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CONTENTS 1. INTRODUCTION.................................................. 2 2. PROTOCOL FILE TRANSFERS....................................... 3 2.1 Graphic File Transfer Display........................... 3 2.2 Choosing the Best Protocol.............................. 4 2.3 ZMODEM-90(TM)........................................... 4 2.4 Sending files with ZMODEM............................... 6 2.4.1 File Maintenance with ZMODEM.................... 6 2.4.2 MobyTurbo Accelerator........................... 6 2.4.3 ZMODEM Compression.............................. 7 2.5 Receiving files with ZMODEM............................. 7 2.5.1 ZMODEM AutoDownload............................. 7 2.6 Tuning ZMODEM Parameters................................ 7 2.6.1 Receiver Window Size Override................... 8 2.7 TERMINAL SERVERS........................................ 8 2.7.1 PORT WATCHERS................................... 10 2.8 7 Bit Environments...................................... 10 2.8.1 Manual ABORT.................................... 10 2.9 XMODEM Family Protocols................................. 10 2.9.1 TRUE YMODEM(TM)................................. 10 2.9.2 YMODEM-1k....................................... 11 2.9.3 YMODEM with OverThruster........................ 11 2.9.4 XMODEM-1k....................................... 12 2.9.5 XMODEM-CRC (with fallback)...................... 12 2.9.6 Classic XMODEM.................................. 12 2.9.7 Relaxed XMODEM.................................. 13 2.9.8 XMODEM with OverThruster........................ 13 2.9.9 YMODEM-g: Traditional Overdrive................. 13 2.9.10 XMODEM Mutants Misrepresented as YMODEM......... 14 2.9.11 Qmodem-G/Streaming XMODEM....................... 14 2.10 Transferring Files with Unix Systems.................... 14 2.10.1 Terminal Servers / Port Multiplexers............ 14 2.10.2 Remote Access vis Telnet........................ 15 2.10.3 Uploading Files to Unix Systems................. 15 2.10.4 The rz and sz Programs.......................... 15 2.10.5 Downloading Files from Unix Systems............. 16 2.11 VAX/VMS File Transfers.................................. 17 2.11.1 Version 4 rz/sz................................. 17 2.12 GEnie File Transfers.................................... 18 2.13 BIX File Transfers...................................... 19 3. FLOW CONTROL.................................................. 20 4. SELECTED COMMANDS............................................. 23 5. Protocol File Transfer OPTIONS................................ 31 6. NUMERIC PARAMETERS............................................ 40 6.1 X/Y/ZMODEM Numeric Parameters........................... 40 7. HARDWARE/SOFTWARE COMPATIBILITY............................... 45 7.1 Hardware Compatibility Notes............................ 45 7.2 Brain Damaged UARTS..................................... 46 7.3 Software Compatibility.................................. 48 8. CROSS REFERENCE INDEX......................................... 53 Chuck Forsberg DSZ Manual Addendum (Selected Pieces of the Pro-YAM Manual) Formatted 9-19-94 For DSZ Users ONLY For DSZ Users ONLY For DSZ Users ONLY For DSZ Users ONLY With Cybernetic Data Recovery(TM) and True YMODEM(TM) Universal Line Printer Edition Copyright 1994 Omen Technology Incorporated All Rights Reserved Omen Technology Incorporated The High Reliability Software 17505-V Northwest Sauvie Island Road Portland Oregon 97231 VOICE: 503-621-3406 :VOICE Modem: 503-621-3746 Speed 1200,2400,9600 Compuserve:70007,2304 GEnie:CAF UUCP: ...!tektronix!reed!omen!caf (C) 1994 Omen Tech Inc Chapter 0 DSZ Manual Addendum Line Printer Draft 2 1. INTRODUCTION The chapters included here are taken from the Pro-YAM manual. Some of the features described here do not apply to DSZ. DSZ does not support ZMODEM Command Download, ZMODEM Security Check, Kermit and certain traditional protocols (WXMODEM, *LINK, MODEM7, etc.). When DSZ is called from a bulletin board or other communications program, automatic ZMODEM file download is not available. ZMODEM AutoDownload is available from DSZ's t command (talk/term function). EXAMPLE: dsz port 1 speed 2400 t -8g Chapter numbers refer to chapters in the ZCOMM user's manual. Welcome to the Rain Forest (_) /~\\ /~\\ / \\/\\ / \\ /\\ / | \\ \\ /\\ / \\ \\/ /|\\ \\ \\ / \\ / \\ / //|\\\\ \\ \\ _/_ \\_/ ___ \\ ///|\\\\\\ _\\_\\ _________________ _______ | ________ -A Usenet Signature (C) 1994 Omen Tech Inc Chapter 1 Protocol File Transfers DSZ Manual Addendum Line Printer Draft Protocol File Transfers 3 2. PROTOCOL FILE TRANSFERS 2.1 Graphic File Transfer Display #---------------------------------------------------------------------# # Professional-YAM Copyright 1991 Omen Technology INC #** # #** # ZMODEM RECEIVE #** # #** # File pcmagc.dmp 1 of 5 #** # #** # Current 43520 of 43520 Total 43520 of 999879 #** # #** # This ################################################## #** # 0------------------------50------------------------100% #** # Total ##- #** # State START FILENAME COMPARE DATA CORRECTING FINISH WAIT #** # Throughput 8704 Retries 0 Time left 2 min #** # Connect ET 13:09 Time 13:18 Modem status #** # #** # #** # Packet LEN 43520 TRANSPORT COMPRESSED DATA BINARY #** # Subpkt LEN 512 Window SIZ #** # ALT-F Cancel File ALT-B Cancel Batch #** # #** #---------------------------------------------------------------------#** ************************************************************************ 38kbps batch file download from a Unix system.[1] ZMODEM-90(TM) compression yields 87kbps effective speed on the PC Magazine Compressible File benchmark.[2] GSZ, ZCOMM and gYAM feature a full screen graphics status display of file transfer statistics. The amount of information displayed depends on the protocol and sending program. XMODEM, CompuServe B+, and Kermit download displays use information supplied to the estimate command. In the absence of a user specified throughput value, Time left is calculated with real time data. Real time throughput may be __________ 1. Pto-YAM screen snapshot made with ALT-Z. The resultant YAMPIC file was renamed to YAMPIC.BIN and read in to THEDRAW. Thedraw output the screen contents in IBM ANSI format, which was then typed and screen dumped to Postsctipt with SCRtoPS(TM) by Olfe Enterprises. 2. Page 159, April 30 1991 PC Magazine. (C) 1994 Omen Tech Inc Chapter 2 Protocol File Transfers DSZ Manual Addendum Line Printer Draft 4 Protocol File Transfers inflated for the first 5-20 kilobytes when a streaming protocol sends data. On PCDOS YAM flavors, call (connect) elapsed time, time of day, and MODEM status are displayed. MODEM status is displayed as follows: x Software flow restraint (XOFF) X Hardware flow restraint (CTS, etc.) L Loss of Carrier Detect signal (CD) H On Hook (DTR off) 2.2 Choosing the Best Protocol A file transfer protocol should have high integrity (assurance of accurate data) and high robustness (low probability of aborting a transfer). And, it should be as fast as possible without compromising reliability. When PC Magazine tested file transfer protocols in early 1991, they ignored the file transfer recommendations given in this manual. Their ignorance slowed Pro-YAM file transfers by as much as 400 per cent. With many different ways to transfer files, your choice of file transfer methods can make the difference between efficient, error free data and slow or error prone transfers. The following subchapters discuss file transfer methods in more detail. 2.3 ZMODEM-90(TM) ZMODEM was developed in 1986 for the public domain (PD) under contract by Telenet, a major packet switched network. Omen Technology's commitment to file transfer technology did not stop with PD ZMODEM. ZMODEM-90(TM) is Omen Technology's copyrighted refinement of PD ZMODEM. ZMODEM-90 speeds transfers with COMPRESSION and other accelerators. ZMODEM-90 adds frame types to support transfers in 7- bit environments. ZMODEM-90 sends files faster and more reliably than PD ZMODEM. Omen Technology's ZMODEM-90 transfers files accurately in many applications where other ZMODEM programs abort or corrupt data. ZMODEM provides a greatly simplified user interface. The file name is entered once, and transfer options may be given to the sending program, even those that apply to the receiver. ZMODEM AutoDownload(TM) allows menu and mouse driven programs to download files and commands with no extra keyboarding required. (C) 1994 Omen Tech Inc Chapter 2 Protocol File Transfers DSZ Manual Addendum Line Printer Draft Protocol File Transfers 5 ZMODEM transfers one or more files with a single command. The size and transfer time for each file is displayed, and the total number of files, size, and transmission time is displayed when more than one file remains to be sent on a command. Keyboarding ALT-F allows the receiver to bypass an individual file without having to restart the batch. ZMODEM transfers both files and commands. Command download allows one of the computers to take positive control of the session. A security challenge (activated by ZMODEM AutoDownload(TM)) guards against Trojan Horse messages.* ZMODEM file transfers can preserve the file date and the exact file contents, unlike traditional protocols that append garbage to files. Streaming transmission provides full throughput over satellite links and packet switched networks. One of three ZMODEM streaming control methods may be used with systems that allow the sender to monitor the received data for error correction packets without interrupting transmission. ZMODEM's "block length" is the entire file! Individually acknowledged packets support other systems. ZMODEM allows programs to adjust the protocol parameters for optimum efficiency as the file is being sent. ZMODEM-90 allows programs to adjust character encoding for best results with a variety of systems. ZMODEM is resistant to conditions that prevent reliable, accurate file transfers with traditional protocols: + ZMODEM data transfers are protected by the Federal Standard 32 bit CRC to assure reliable transfers. This 32 bit CRC gives an undetected error rate five orders of magnitude better than XMODEM's 16 bit CRC, and more than a billion times better than checksum XMODEM. ZMODEM uses 16 bit CRC for file transfers with programs that do not support 32 bit CRC. + Most important, all ZMODEM protocol transactions are protected by CRC. Other protocols advertising 16 or 32 bit CRC sometimes fail under stress because critical control messages are not CRC protected. If you've ever been disconnected when a huge file transfer was almost finished, you'll appreciate resuming/recovering the file transfer with ZMODEM Crash Recovery Omen Technology Incorporated's Intelligent Crash Recovery(TM) guards against file corruption during Crash Recovery operations. (ZMODEM r and rr options.) (C) 1994 Omen Tech Inc Chapter 2 Protocol File Transfers DSZ Manual Addendum Line Printer Draft 6 Protocol File Transfers 2.4 Sending files with ZMODEM To send a file with ZMODEM, the command sz file1 can be given from either the main command prompt, or from the term function via a secondary command prompt obtained with ALT-2. Multiple files and wild cards may be used. EXAMPLE: sz file1 file2 *.lst Please refer to the sz and zcommand commands in Chapter 19 for more examples and information. 2.4.1 File Maintenance with ZMODEM Omen Technology ZMODEM gives you the tools to maintain up to date files on multiple machines. You can use the ZMODEM n option to transfer only those files that have changed since the last time they were transferred. With the p option, you can unconditionally protect files that exist on the destination system. To update only the files you already have while skipping the rest, use the Yn options. You can update an entire directory tree with the R option. EXAMPLE: sz -n -f -R chart sends the chart directory and all its subdirectories. The -n option skips old files. The -f option causes the pathname to be sent; otherwise all files would appear in the same directory on the receiving system. SEE ALSO: File Transfer Options, Chapter 20. 2.4.2 MobyTurbo Accelerator Standard ZMODEM escapes network control characters. This causes a slight drop in throughput when sending compressed files. When transferring compressed files over circuits that pass all 256 8 bit codes, MobyTurbo(TM) may be used to optimize speed. MobyTurbo provides the raw transfer speed of YMODEM-g and other fragile protocols without sacrificing ZMODEM's safety or robustness. MobyTurbo is activated with the m option. The m option may be used with the sz or rz command. EXAMPLE: sz -m *.zip MobyTurbo may be used with ZMODEM AutoDownloads by adding the m option to the DSZOPT environment variable. EXAMPLE: C>set DSZOPT=m (C) 1994 Omen Tech Inc Chapter 2 Protocol File Transfers DSZ Manual Addendum Line Printer Draft Protocol File Transfers 7 SEE ALSO: m file transfer option 2.4.3 ZMODEM Compression ZMODEM-90 programs support ZMODEM compression for fast transfers of compressible files with the Z file transfer option. The amount of compression (and speed increase) depends on the structure of data in the files. EXAMPLE: sz -Z pcmagc.dmp SEE ALSO: Z file transfer option 2.5 Receiving files with ZMODEM 2.5.1 ZMODEM AutoDownload YAM's term function (t command) will detect a ZMODEM transmission, and receive the file(s) automatically. File transfer options for ZMODEM automatic downloads may be specified with the DSZOPT environment variable. EXAMPLE: C> set DSZOPT=m Requests MobyTurbo(TM) accelerator for downloads. .H 3 "Manual ZMODEM Downloads" The rz command may be also given from a command prompt. SEE ALSO: rz command 2.6 Tuning ZMODEM Parameters Chapter 24.2 describes a number of ZMODEM numeric parameters which may be adjusted for extraordinary situations, or to fine tune the last 0.1 per cent of possible performance. The ZMODEM subpacket length (zmodem L parameter) and the ZMODEM frame length (zmodem l parameter) deserve special mention. People tend to confuse these with the familiar 128 and 1024 byte block length used in XMODEM transfers. When a ZMODEM frame length of 0 is specified (the default), a single frame will span the entire file if there are no errors. This is the main source of ZMODEM's reputation for fast transfers. Setting the ZMODEM frame length to a number between 64 and 16384 restricts the frame length to that value. At the end of each frame, the sender stops sending and waits for an acknowledgement from the receiver. When set, the ZMODEM frame length corresponds in function to the 128 or 1024 byte block length of XMODEM based protocols. Each ZMODEM frame consists of one or more subpackets of 32 to 1024 bytes. Since the subpackets within a frame are sent without pause, a short subpacket length does not exact the terrible throughput penalty (C) 1994 Omen Tech Inc Chapter 2 Protocol File Transfers DSZ Manual Addendum Line Printer Draft 8 Protocol File Transfers associated with short XMODEM and Kermit blocks. In the absence of transmission errors, a 256 byte subpacket length has about two per cent more overhead than a 1024 byte subpacket length. However, the longer subpacket length does increase error recovery time. Professional-YAM dynamically adjusts the ZMODEM subpacket length on the basis of transmission speed and observed error rate. If you know what the error rate on a particular call will be before starting a ZMODEM file transfer, setting the zmodem L numeric parameter will provide a small but noticeable improvement in performance, with 1024 best for clean lines and smaller numbers better for noisy lines. When sending files over noisy phone lines not involving networks, the speed of error recovery may be increased by decreasing the values of the ZMODEM t and p numeric parameters. Information about YMODEM and ZMODEM protocol internals is provided in ymodem.doc and zmodem.doc, part of Omen Technology's ZMODEM Developer's Collection. 2.6.1 Receiver Window Size Override Some ZMODEM senders control the network window size to improve error recovery and/or overcome incorrect flow control configuration. The optimum size of this depends on the average error rate on the link, information that may not be available to the sender. ZMODEM-90(TM) allows the receiver to specify the window size, with the Wn option, overriding the sender's window size. SEE ALSO: Wn option 2.7 TERMINAL SERVERS Terminals on some timesharing systems are connected indirectly to the host with TERMINAL SERVERS operating over networks. Terminal servers often interfere with file transfers by "eating" control characters and/or losing data. Accessing a distant system using telnet or rlogin on a local Unix system entails the same problems. If you have a choice between telnet and rlogin try rlogin with the -8 option. Set the escape character to ^P (control P) which is protected by ZMODEM. When terminal servers interfere with file transfers, server commands are often available to help the problem. When possible, enable the server and modems for hardware flow control in and out. Set the terminal server to telnet transparent mode. Some typical commands are "SET TERMINAL DOWNLOAD", "set session passall", and "SET TERMINAL NO ESC", but there is no standard set of commands suitable for all terminal servers. Normally these commands are given before attempting file transfers, but one user has reported that the command must be given after the file transfer is started(!). Until terminal server (C) 1994 Omen Tech Inc Chapter 2 Protocol File Transfers DSZ Manual Addendum Line Printer Draft Protocol File Transfers 9 vendors improve the quality of their product, you may have to get on their case until they adequately support high performance file transfers. Escaping control characters with ZMODEM (sz -e) may help if the transfer gets stuck in the same place on every attempt. Professional-YAM and ZCOMM allow selection of which control characters need to be escaped. In extreme cases 7-bit transmission may be required (see the Professional-YAM/ZCOMM manual). If you encounter problems with control characters you should identify which control characters are causing the problem. Please refer to the sz -T command in sz.doc for more help. Flow control between the server and modem is often defective. This rarely causes a problem in interactive applications whose short bursts (a screenfull at most) fit within the available memory buffers. Streaming protocols such as YMODEM-g, long packet SuperKermit, and ZMODEM can overload the available buffering. Some terminal servers support commands to enable hardware flow control such as "TERM FLOWCONTROL HARDWARE IN OUT"; this assumes the modem attached to the server is properly configured. If the terminal server is too brain damaged to support flow control, ZMODEM lets you fake it by setting a window size. Try sz -w2048 file... to enable software flow control. Experiment with different window sizes for best results. Terminal servers are designed to accept keyboard input from human operators. They may lose data when a program sends more data to the host faster than humans type. Some servers allow larger input buffers to support file uploads. If you can upload short files (less than 100 bytes) but not longer files, try sz -w1024 file... with your uploading program. (Not all programs support this option; use ZCOMM or Professional-YAM.) When both flow control and character transparency are problems, use sz -ew1024 file... as a starting point. Sometimes the terminal server software is defective and must be corrected. Please contact the network's vendor for corrective procedures. An alternative is to install direct serial ports for users desiring to upload files. We have also encountered problems when networking software fails to pass data after a large amount of data has been sent to the host. This has happened on a PPP internet connection which prevented uploads of large amounts of data via either FTP or a ZMODEM upload (via TELNET). The PPP connection grinds to a standstill and not even PING (C) 1994 Omen Tech Inc Chapter 2 Protocol File Transfers DSZ Manual Addendum Line Printer Draft 10 Protocol File Transfers works. The same ZMODEM/TELNET combination easily uploaded ten times as much to a nearby machine connected by Ethernet. 2.7.1 PORT WATCHERS Some systems enforce a timeout which disconnects a user after several minutes of keyboard inactivity. Long, error free ZMODEM transfers do not generate keyboard activity (this is why ZMODEM is so efficient). Restricting the window size with sz -w16384 file... option generates terminal input at regular intervals even when no error correction is needed. If problems persist, try setting a packet length. sz -l1024 file... (The default ZMODEM packet length is the file length.) The sz e and m options may be used in conjunction with the xmtxesc and zmrxesc string parameters to specify more control characters which cannot be passed over the serial line. SEE ALSO: zmtxesc, zmrxesc string parameters 2.8 7 Bit Environments ZMODEM-90 automatically detects 7 bit environments and adjusts accordingly. If the environment is known to be 7 bits, use the E option to provide 7 bit compatibility in minimum time. EXAMPLE: sz -E file.doc When transferring files with a large number of bytes with the 8th bit set, the P ("pack") option may be used to optimize 7 bit encoding. EXAMPLE: sz -P zipfile.zip 2.8.1 Manual ABORT If a ZMODEM transfer fails abruptly under exceptional conditions the program on the remote machine may be manually terminated by repeatedly typing Ctrl-X characters at it until the program exits. 2.9 XMODEM Family Protocols All XMODEM family protocols require an absolutely transparent data path from sender to receiver. Modems must not be configured for software flow control. 2.9.1 TRUE YMODEM(TM) Developed in 1981, YMODEM is finding its way into many communications programs. With Omen Technology's Enhanced Data Recovery(TM), YMODEM gives excellent efficiency, integrity, and fair robustness in many applications. (C) 1994 Omen Tech Inc Chapter 2 Protocol File Transfers DSZ Manual Addendum Line Printer Draft Protocol File Transfers 11 True YMODEM transfers one or more files in a batch, without alteration or added garbage characters. True YMODEM also preserves the file date across multiple time zones. Professional-YAM and the Unix(TM) rb and sb programs preserve the file modification date.[3] 2.9.2 YMODEM-1k The sb k option (1024 byte blocks) may be used to enhance throughput, especially when using timesharing systems, satellite links, or packet networks that can support the longer blocks. EXAMPLE: sb -k *.c *.h sends all .c and .h files in the current directory with 1024 byte blocks.[4] YMODEM and YMODEM-1k transfers can be received with the rb or F3 commands. YMODEM file transfers with Unix and VMS systems are discussed later in this chapter. Some programs claim to support YMODEM but actually use XMODEM with 1024 byte blocks. These programs do not meet the YMODEM Minimum Requirements defined by the YMODEM protocol. One can use Pro-YAM's XMODEM sx -k and rc commands with these traditional programs. 2.9.3 YMODEM with OverThruster YMODEM and YMODEM-1k file downloading from networks and timesharing systems is slowed by response times. This slowing may be significant even when 1k blocks are used. With some systems, one can speed up YMODEM downloads by using the o option with the rb command to receive the file. Because OverThruster(TM) defeats error recovery, a line hit will usually abort a download. OverThruster(TM) may be used with X.PC or MNP error correcting link level protocols. EXAMPLE: rb -o SEE ALSO: O numeric parameter __________ 3. Controlled by the d and z numeric parameters 4. YAM switches to 128 byte blocks at the end of a file when the length warrants. (C) 1994 Omen Tech Inc Chapter 2 Protocol File Transfers DSZ Manual Addendum Line Printer Draft 12 Protocol File Transfers 2.9.4 XMODEM-1k The XMODEM-1k protocol transfers one file per command with 1024 byte blocks and a nominal 16 bit CRC. The file name must be entered for both the sender and the receiver. Programs lacking YAM's Cybernetic Data Recovery(TM) logic are less likely to transfer data accurately under marginal conditions. XMODEM's use of every possible 8 bit code causes problems in some applications. The end of the file may be padded by up to 127 or 1023[5] garbage characters. To send a file with XMODEM-1k: sx -k file1 To receive a file with XMODEM-1k: rc file1 2.9.5 XMODEM-CRC (with fallback) The XMODEM-CRC protocol transfers one file per command. The XMODEM-CRC protocol requires the receiving program to initiate an XMODEM-CRC transfer. The file name must be entered for both the sender and the receiver. Even with CRC-16, programs lacking YAM's Cybernetic Data Recovery(TM) are less likely to transfer data under marginal conditions. XMODEM- CRC's use of every possible 8 bit code causes problems in some applications. The end of the file may be padded by up to 127 garbage characters. To send a file with XMODEM (or XMODEM-CRC): sx file1 To receive a file with XMODEM-CRC: rc file1 2.9.6 Classic XMODEM The original MODEM protocol, developed by Ward Christensen, is supported by a large and growing number of programs operating on a variety of micros and minis. The base level XMODEM protocol gives good results when used over low error rate direct telephone connections. XMODEM's short data blocks and use of every possible 8 bit code preclude its application in many environments. File transfers with this protocol add up to 127 garbage characters to transferred files. The XMODEM protocol can transfer one file per command. The file name must be entered at both the sender and the receiver. To send a file with XMODEM: sx file1 To receive a file with Classic XMODEM: rx file1 __________ 5. Some programs (including YAM) limit this padding to 127 bytes. (C) 1994 Omen Tech Inc Chapter 2 Protocol File Transfers DSZ Manual Addendum Line Printer Draft Protocol File Transfers 13 2.9.7 Relaxed XMODEM Professional-YAM's XMODEM and YMODEM support has been optimized for maximum reliability with a wide variety of systems under a wide variety of conditions. The default XMODEM and YMODEM timeout parameterss are "relaxed" timings. They rarely need to be lengthened except under the most sluggish of conditions. The zmodem t, T, and p numeric parameters (q.v.) control timeouts for XMODEM, YMODEM, and ZMODEM. The default values allow 10 seconds for a packet to appear and a 10 second pause within a packet before starting error recovery. EXAMPLE: zmodem pt200 pp150 :: Set more relaxed X/Y/ZMODEM timing For best reliability, Omen Technology does not recommend tightening these timings for XMODEM and YMODEM transfers on noisy lines. 2.9.8 XMODEM with OverThruster XMODEM file downloading from networks and timesharing systems is slowed by short blocks and long response times. With some systems, one can speed up downloads by using the ro command to receive the file. Because OverThruster(TM) defeats error recovery, a line hit will usually abort a download. With nearly error free connections, one can save enough time from the increased throughput to make up for the failed transfers. OverThruster(TM) may be used with X.PC or MNP error correcting link level protocols. EXAMPLE: ro file1 EXAMPLE: rb -o SEE ALSO: O numeric parameter 2.9.9 YMODEM-g: Traditional Overdrive The proliferation of error correcting modems has sparked a proliferation of YMODEM-g programs, more and more of which actually meet minimal YMODEM protocol specifications. YMODEM-g transmits 0 or more files per batch with an ACK-less variant of YMODEM-1k. The sender does not wait for individual data blocks to be acknowledged, allowing high speed transfers with error correcting modems. YMODEM-g assumes an error free communications channel. A single transmission error or character lost because of DOS or TSR interrupt latency ruins the entire transfer, and YMODEM-g does not support Crash Recovery(TM). YAM supports True YMODEM-g with the sb and rb -g commands. (C) 1994 Omen Tech Inc Chapter 2 Protocol File Transfers DSZ Manual Addendum Line Printer Draft 14 Protocol File Transfers EXAMPLE: sb *.old Sends files in the current directory with YMODEM or YMODEM-g protocol. The receiver controls whether YMODEM or YMODEM-g is used for the transfer. EXAMPLE: rb -g Receives with YMODEM-g protocol. 2.9.10 XMODEM Mutants Misrepresented as YMODEM Despite continuing education efforts, a few lazy software providers insist on identifying their mutant XMODEM protocols as "ymodem". They choose to ignore the definition of YMODEM that Ward Christensen wrote when he coined the term YMODEM in his April 1985 message: (a) a record 0 containing filename date time and size (b) a 1K block size option (c) CRC-16. Use the XMODEM sx-k and rc commands to deal with these nonstandard programs. In case of questions, please refer to ymodem.doc, part of yzmodem.zoo for for the official YMODEM protocol. (Available in Omen's ZMODEM Developer's Collection.) 2.9.11 Qmodem-G/Streaming XMODEM The Qmodem program and certain bulletin boards provide an ACKless XMODEM mutant protocol selected with the Qmodem G protocol menu choice. The sx and rx -g commands support this mutant XMODEM. EXAMPLE: rx -g qmodem.fil 2.10 Transferring Files with Unix Systems 2.10.1 Terminal Servers / Port Multiplexers Some Unix systems are accessed via a port multiplexer or other network. Some of these interfere with data transmission. In some cases it has been necessary to contact the manufacturer to obtain undocumented instructions or software updates to make the multiplexers or networks suitable for file transfers. These systems may require additional control characters to be escaped. The sz command e option may be used to escape all control characters. SEE ALSO: e option Individual control characters can be escaped with the zmtxesc string parameter. (C) 1994 Omen Tech Inc Chapter 2 Protocol File Transfers DSZ Manual Addendum Line Printer Draft Protocol File Transfers 15 SEE ALSO: zmtxesc string parameter Sometimes it is necessary to use 7-bit transfers with the E or EP options. EXAMPLE: sz -EP bigkahuna.zip 2.10.2 Remote Access vis Telnet Sometimes one wishes to access a distant host by calling into a nearby Unix system. The Unix telnet program may be used to access other hosts. When using telnet, the -8 option should be used to enable an 8 bit path. The telnet escape character should be set to Control-P, a character which is protected by standard ZMODEM. EXAMPLE: telnet -8 -e ^P localhost 2.10.3 Uploading Files to Unix Systems Files may be sent to Unix systems conveniently and quickly with ZMODEM. Unix flavors of Professional-YAM support the full ZMODEM-90(TM) feature set including Intelligent Crash Recovery(TM) and selective transfers with the rz command, a hard link to the /usr/bin/yam program. If the Unix system is operating with 7 bits, the sender's zmodem d parameter may have to be increased to allow the rz program time to change Unix to 8 bits for the transfer. SEE ALSO: zmodem d numeric parameter Traditional Unix systems limit serial input buffering to a few hundred characters or less. This is sometimes too small to prevent data loss and retransmissons when operating at high speeds. On SCO Unix 3.2.4 this bufering can be increased by increasing the TTYHOG and NCLIST kernel parameters. 2.10.4 The rz and sz Programs Professional-YAM is the fastest Unix ZMODEM upload program. Pro-YAM uses a minimum of CPU resources for uploads. Pro-YAM provides the best ZMODEM technology and feature set available., but it may not be available on a particular system. The rz program, part of the rzsz package, may be used to support a subset of Pro-YAM's ZMODEM features. If rz is not installed on the target Unix system, unpack the rzsz.zoo file on your MSDOS system with: booz x rzsz.zoo given from the DOS prompt.[6] Next, the command source zupl.t calls the zupl.t script to (C) 1994 Omen Tech Inc Chapter 2 Protocol File Transfers DSZ Manual Addendum Line Printer Draft 16 Protocol File Transfers upload the bootstrap file minirb.c, compile it, and use it to upload the remainder of the source files. After the rest of the files have been uploaded, compile rz.c and sz.c using the directions given in the README file and in the C source files. The rz and sz manual pages may be formatted with a make doc command. The undos program may be used to remove carriage returns in files uploaded to Unix machines. 2.10.5 Downloading Files from Unix Systems To download files from Unix(TM) systems, use the Unix sz command to send the desired files to YAM. To Unix keyboard: sz file ... Professional-YAM's ZMODEM AutoDownload(TM) takes care of the rest for you, saving unnecessary keystrokes. If one or more of the files already exists on the destination disk, use sz -y file ... instead, to replace the old copies on your computer. Another useful option sends only the files that exist on both computers (Y), and furthermore sends only those that are newer (n): sz -Yn file ... When files are long and transmission slow, you can save time by compressing them first. The zoo program, available for DOS, Unix, and VMS, may be used to compress file(s) before transmission. Other suitable programs include compress, zip, and gzip. Omen Technology products support ZMODEM compression with the Z option. All Omen Technology products support compression by Run Length Encoding (RLE). Unix flavors of Professional-YAM also support LZW compression. Unix source files normally do not contain carriage returns used by CP/M and DOS. Some CP/M or DOS programs, such as C compilers, do not require carriage returns in the source files. Others, such as the Microsoft Macro Assembler, become quite confused by such files, although such files fully meet the requirements of the ASCII standard. Carriage Returns may be added before downloading with the todos or tocpm programs. Carriage returns may be added during the transfer ______________________________________________________________________ 6. On Unix systems with Professional-YAM installed, the rzsz source files and man pages are installed in the /usr/src/command/rzsz directory, or on the distribution diskette in the file /tmp/yamusrc.tar.Z. (C) 1994 Omen Tech Inc Chapter 2 Protocol File Transfers DSZ Manual Addendum Line Printer Draft Protocol File Transfers 17 with the sz -a option. Carriage Returns may be added after the transfer by some program editors, including uEMACS. Short files (less than 64kb) may be converted using YAM's read and create commands to pass the data through YAM's capture buffer. Text files may also be downloaded using the capture buffer if sz has not been installed on the Unix machine. If a file or set of files are to be transported between two Unix systems, it may be helpful to place them in a tar or cpio archive (and possibly compress the archive) before transmission. This procedure will preserve the Unix file modes and modification times, and bypass pathname restrictions imposed by DOS. As with rz, Unix Professional-YAM is linked to sz to support the full ZMODEM-90(TM) feature set. Otherwise the separate Unix sz program may be obtained as described in the previous subchapter. 2.11 VAX/VMS File Transfers Most of the comments made above about Unix file transfers apply to VMS as well. Many VAX/VMS systems attach terminals with terminal multiplexers just as nasty as those used with Unix systems. They require fixes similar to those described above for Unix systems.. Automatic uploads to VMS may require setting the zmodem d (delay) numeric parameter to give time for the VMS rz program to properly initialize. SEE ALSO: zmodem d numeric parameter EXAMPLE: zmodem pd15 2.11.1 Version 4 rz/sz Omen provides VMS flavors of version 4 rz and sz precompiled in rzsz.tlb, a VMS "text library". Version 4 rz supports most ZMODEM-90 features including Crash Recovery, compression, and MobyTurbo. Binary uploads write files with a default VMS 512 byte fixed length record format. EXAMPLE: sz biglib.tlb Sending to VMS with the i option selects the VMS Stream_LF record format. Stream_LF preserves the exact file length and data contents when read by C programs. EXAMPLE: sz -i vmsemacs.exe Sending to VMS with the I option causes the VMS receiver to use (C) 1994 Omen Tech Inc Chapter 2 Protocol File Transfers DSZ Manual Addendum Line Printer Draft 18 Protocol File Transfers variable length binary records. VMS Kermit-32 and some other programs understand this record format. Text files uploaded with the a option are written in variable length records with CR carriage control. EXAMPLE: sz -a emacs*.c Version 4 VMS sz supports standard VMS wild card and directory recursion syntax. EXAMPLE: $ sz -qa [*...]*.prn sends all accessible .prn files on the system in ASCII mode. The VMS sz q option suppresses the initial tally of the number of files and their lengths. This tally can take some time when a large number of files and directories are invloved. The f option may be added to send directory names as well. If you use Kermit to upload the rzsz.tlb file to VMS, command the receiving Kermit program to SET FILE TYPE FIXED. (Some VMS Kermit programs may require SET FILE TYPE BLOCK.) Otherwise Kermit will garble the data. 2.12 GEnie File Transfers The General Electric Consumer Information Service service (GEnie) uses ZMODEM-90(TM) for efficient downloads. GEnie's ZMODEM server selects ZMODEM RLE Compression or MobyTurbo(TM) for optimum download speed on each file. GEnie uses a large network to provide callers with local access numbers. This requires technical tradeoffs to control data flow in the network. If you have a reliable, error-free connection to GEnie, download speeds can be improved by increasing GEnie's ZMODEM window size. EXAMPLE: C> set DSZOPT=W16384 The sx file.exe command is used for XMODEM-CRC uploads to GEnie. When uploading with XMODEM-CRC, Wait for GEnie's "READY FOR INPUT, start your XMODEM upload." message, and then wait for the XMODEM-CRC C to appear before issuing the sx command. Issuing the sx command before the C appears may corrupt the uploaded file. A number of GEnie access scripts are provided in scripts.zoo with filenames starting with ge. The main GEnie login script is provided in phones2.t witin scripts.zoo. (C) 1994 Omen Tech Inc Chapter 2 Protocol File Transfers DSZ Manual Addendum Line Printer Draft Protocol File Transfers 19 2.13 BIX File Transfers BIX (Byte Information Exchange) supports ZMODEM-90 and Kermit file transfers. The Tymnet phone number in the bix telephone directory entry should be changed for your calling area. Other scripts are provided to handle BIX mail and conferences. When setting up a new BIX account, give the command call bix,new to force a login to the BIX new account program. Be sure to select ZMODEM downloads and uploads with the BIX "OPTIONS" menu choice. Set the DSZOPT environment variable m or mr to enable MobyTurbo and ZMODEM Crash Recovery. When uploading over Tymnet or other networks, it may be necessary to set the zmodem w numeric parameter to a value between 2048 and 8192 for best upload performance. The optimum value depends on load and the particular node you dial in to. EXAMPLE: z pw6144 BIX's transfer time predictions are about 40 per cent too pessimistic for ZMODEM transfers. A number of BIX scripts are included in SCRIPTS.ZOO. //-n-\\ _____---=======---_____ ====____\ /.. ..\ /____==== // ---\__O__/--- \\ \_\ /_/ Enterprise... Surrender or we'll send back your *&^$% tribbles !!! -A Usenet Signature (C) 1994 Omen Tech Inc Chapter 2 Flow Control DSZ Manual Addendum Line Printer Draft 20 Flow Control 3. FLOW CONTROL All of us must sometimes tell people to "slow down" lest they overload us with information faster than we can write it down. "Wait!" is a Flow Control Signal for the English language. When the receiving Pro-YAM complains about Garbled Data Subpacket or Line Status Register 01 you should suspect a flow control problem. When buffered modems, timesharing systems, networks, or computers of differing speeds are involved, a machine readable "Wait!" signal is required. Flow control is sometimes necessary to display long messages without skipping over the good parts. If you see pieces of text missing from messages but don't see the usual funny characters caused by line noise, you have a flow control problem. File transfers that use long blocks or streaming protocols may not work well unless slower parts of the system regulate the speed of transmission to prevent loss of data. With ZMODEM, SuperKermit, and other streaming protocols, inexplicable retransmissions of data blocks, often at regular intervals, indicate flow control failure. If you wish to keep things simple, the sending computer should not operate at a higher interface speed than the slowest link in the network. Otherwise precautions must be taken to prevent data loss with interactive operations and unnecessary retransmissions with streaming file transfer protocols. YAM, ZCOMM, and DSZ default to software flow control with XON and XOFF characters.[1] When used with modems that require hardware flow control, the handshake command (q.v.) should be used to specify which hardware lines are to be used for flow control. Non transparent software flow control is incompatible with Emacs editors, XMODEM and YMODEM transfers. XMODEM and YMODEM require complete transparency to all 256 8 bit codes. An XMODEM transfer that always fails at the same block results from non transparent flow control. When XMODEM-1k and YMODEM-1k are used, the network must assert flow control, or handle bursts of 1040 characters without data loss. When X.25 or hardware CTS is unavailable, flow control that does not "eat" any characters may be used with XMODEM and YMODEM. When buffers fill up, an XOFF should be emitted. An XON should be __________ 1. The PCDOS flavor enables "handshake both" when selecting a port with an active Clear To Send (CTS) signal that was previously initialized to a speed greater than 2400 bps (C) 1994 Omen Tech Inc Chapter 3 Flow Control DSZ Manual Addendum Line Printer Draft Flow Control 21 sent when the buffer has emptied. Otherwise, the network should neither generate nor eat XON or XOFF characters. On Telenet, this is obtained by setting CCIT X3 5:1 and 12:1 in the PADs (Packet Assembler Disassembler) at both ends of the network. Packets should be forwarded when the packet is a full 128 bytes, or after a moderate delay (3:0,4:10). Set parameter 5 to 1 at both ends AFTER one is connected to the remote modem. (Sorry, these commands must be given each time you connect to a modem in the far city!) <ENTER>@<ENTER> set 5:1<ENTER> rst? 5:1<ENTER> cont<ENTER> ZMODEM and Kermit protect all 4 XOFF and XON characters, commonly used network control characters and trigger strings. ZMODEM and Kermit are compatible with many networks that do not support XMODEM family protocols, including some that claim network compatibility. For PADs that do not accept "rst?", use: <ENTER>@<ENTER> set 4:2,5:1,12:1<ENTER> cont<ENTER> For best Telenet download throughput, parameter 64 (advance ACK) should be set to 7. The parameter 0 is a dummy argument that distinguishes Telenet parameters from CCIT parameters. <ENTER>@<ENTER> set 0:0,64:7<ENTER> cont<ENTER> Sometimes Telenet flow control stops data transmission when the network buffers are not yet full. If you often see "STOPPED" flashing in the status line (DOS versions), or if you see the modem send data light pause in a ZMODEM or SuperKermit file send, poor flow control may be the culprit. Such slowdowns are typical when a network is overloaded. If this condition persists, the network should take steps to reduce the congestion. Turning OFF network flow control and activating ZMODEM's or SuperKermit's protocol flow control may increase throughput under these conditions. Instead of or in addition to XON/XOFF flow control, the sending program's ZMODEM w numeric parameter can restrict the window size to a value that does not overload the network. A zmodem pw2048 command restricts the window size (maximum number of bytes in transit) to 2048. This causes the sz command to trigger the receiver's acknowledgement every 512 bytes (one fourth the value of the ZMODEM w numeric parameter). The sender monitors these responses and suspends transmission when necessary to restrict the window to the specified size. Until a network dependent lower limit is reached, lower window sizes improve the speed of error recovery at the expense of slight increases in protocol overhead. When the window size becomes less than the number of characters sent within the network's transit time, throughput falls off rapidly. Frequent protocol acknowledgements slow down high speed pseudo full duplex modems (US Robotics HST, Telebit (C) 1994 Omen Tech Inc Chapter 3 Flow Control DSZ Manual Addendum Line Printer Draft 22 Flow Control TrailBlazer) and should be avoided. ZMODEM-90(TM) allows the receiver to specify the window size with the -Wn option where n is the desired window size. requests an 8192 byte window size. Some modems and networks can be configured to flush (discard the contents of) their buffers when a break signal is received. If this is possible, error recovery with ZMODEM transfers may be speeded up by setting the ZMODEM b parameter to 1, which sends a break whenever the ZMODEM sending program gets a retransmission request. Network and Flow Control (FC) Compatibility ______________________________________________________________________ | Network | Interactive | XMODEM | WXMODEM | S-KERMIT | ZMODEM | |________________|_____________|________|_________|__________|________| |No Network | YES | YES | YES | YES | YES | |8 bit, no FC | NO | YES | YES | YES(1) | YES(1) | |Transparent FC | YES | YES | YES | YES | YES | |Non Transparent | YES | NO | NO | YES | YES | |7 bit | YES | NO | NO | YES | YES(2) | |________________|_____________|________|_________|__________|________| (1) Window size must be restricted to avoid buffer overrun if the network cannot transfer data at full speed. (2) Requires ZMODEM-90(TM) 7-bit support (C) 1994 Omen Tech Inc Chapter 3 Selected Commands DSZ Manual Addendum Line Printer Draft Selected Commands 23 4. SELECTED COMMANDS Commands and arguments must be entered in lower case except where stated. estimate length speed Use the specified length and specified effective speed for the next receive file to be created. A length of 0 bypasses the length substitution. Once a speed (in effective bits per second) is given, it is used for all locally displayed transmission time calculations until the next speed or port command. EXAMPLE: "speed 19200; estimate 0 2400" Use an effective transmission speed of 2400 for transmission time estimates instead of the 19200 bps interface speed. HAndshake {off|on|cts|dsr|dcd|both|slow} Some modems and printers cannot accept continuous full speed data. These devices send control characters (XOFF and XON) for flow control, or generate a hardware flow control signal on the CTS, DSR, or DCD pin. The Handshake command controls the modem port hardware handshake (default off). If hardware handshaking is selected, an ON to OFF transition on the specified line pauses transmission, and an XON character will not override the hardware restraint. After a timeout set by the S numeric parameter (default 60 seconds), or if characters are in the keyboard input buffer, a warning message is displayed, the restraint is released, and characters are sent. As a special case, handshake on obeys output flow control with the CTS input signal, asserts input flow control with the RTS output signal, and disables the transmission of XOFF characters when the modem input buffer becomes nearly full. In addition, handshake slow drops the RTS output signal while writing to disk when receiving with XMODEM, YMODEM, or ZMODEM. The command handshake both allows either CTS or XOFF to pause output, in addition to asserting input flow control with the RTS output. The handshake dcd command enables d term option (q.v.). Subsequently, selecting a different type of handshaking will disable d term option. The handshake command releases flow control (allows data to flow if it had been stopped by handshaking). Changing the communcations port with the port or portx command disables hardware handshaking. (C) 1994 Omen Tech Inc Chapter 4 Selected Commands DSZ Manual Addendum Line Printer Draft 24 Selected Commands SEE ALSO: S numeric parameter EXAMPLE: handshake cts Turns on CTS handshaking. port n Change the modem port to COMn. On DOS, the legal values for n are 1...18. Selecting a new port normally selects software handshaking ("handshake sw"). The PCDOS flavor enables both hardware and software handshaking ("handshake both") iff the port speed exceeds 2400 bps and the Clear To Send (CTS) signal is active at the time the port command is given. Standard Ports (PCDOS): COM1 3F8 IRQ4 (Standard IBM) COM2 2F8 IRQ3 (Standard IBM) NON STANDARD PORTS: COM3 3E8 IRQ4 (Alternate) COM4 2E8 IRQ3 (Alternate) COM5 2B8 IRQ3 (Columbia) COM6 2B8 IRQ2 (Alternate for IBM) COM7 2E8 IRQ5 (Alternate "COM3") COM8 3E8 IRQ5 (Alternate "COM4") COM9 Uses the port address and interrupt vector previously set by the portx command. COM1 and COM2 are the standard serial ports defined by the IBM Technical Reference Manual. COM3 and COM4 are supported by many serial cards and modem boards. COM3 and COM1 share the same dedicated hardware interrupt line, and these ports may not be used at the same time. Likewise, COM4 and COM2 may not be used at the same time. Columbia computers support COM5. COM6 to COM8 are alternate configurations that may be accessed by cross jumpering between printer port decoders and serial port enables on some multifunction boards. COM7 and COM8 support alternative definitions for "COM3" and "COM4" respectively. Since YAM uses the interrupt line on the selected port, no other program or device driver may use the same port address and/or interrupt vector concurrently. Certain disk controllers and mice (C) 1994 Omen Tech Inc Chapter 4 Selected Commands DSZ Manual Addendum Line Printer Draft Selected Commands 25 interfaces use IRQ2 and IRQ5. IRQ5 is sometimes used by network cards and printer ports. Ports sharing the same interrupt vector (IRQ number) cannot be used concurrently. The port command sets the d term option (which suppress the No Carrier Detect message). EXAMPLE: port 2 DOS YAM begins with COM1 unless overridden by the DPORT environment variable. EXAMPLE: C>set DPORT=2 On Unix, the argument of the port command is a character special file in the /dev directory. Unix and Xenix flavors have no default port. If the DPORT environment variable is set, that port will be selected when Pro-YAM initializes. Otherwise, a port is selected by the startup and/or dialing script. Typical values are tty01 (386/ix) and tty2A (Xenix). EXAMPLE: DPORT=tty1A; export DPORT If the port is in use by another program that supports UUCP port arbitration, or otherwise not accessible, port selection fails and the error counter is incremented. EXAMPLE: pe0; port tty1A; if !e goto gotport pe0; port tty1B; if !e goto gotport pe0; port tty1C; if !e goto gotport echo "No Ports available"; fail gotport: SEE ALSO: handshake command, dport string parameter, e test condition portx hbase,irq[,divisor] * To support specialized multiport serial interfaces, the portx command selects a communications port with a specified hexadecimal base address hbase and Interrupt Request Line irq (3 <= irq <= 15).[1] Nonstandard baudrate clock inputs are supported with the optional divisor argument. To support a __________ 1. IRQ2 can be used on some machines, on others it must be specified as IRQ9. (C) 1994 Omen Tech Inc Chapter 4 Selected Commands DSZ Manual Addendum Line Printer Draft 26 Selected Commands nonstandard bit rate source, multiply 5760 by the new raw bit rate source frequency in MHz divided by 1.84320. The portx does not check its argument for validity. The consequences of an invalid selection are quite undefined. The specified base address and IRQ number are assigned to COM9, where they may be used by the port command and the x numeric parameter. The status line and s command will indicate COM9. This command not available on X.PC, Unix, Xenix, or OS/2. EXAMPLE: portx 3e8,15,57600 Selects a comm port with a base address of 3e8 using IRQ15 and the 18.432 MHz clock option on the Boffin Electronics "WinSport II" 2 port serial board. rb [-options] Receives with options 1 or more files using YMODEM protocol. The rb command also receives files sent with SEAlink protocol. Chapter 20 describes the available options. YMODEM transmits the pathname and length of each file. If a file is received in error (retries exhausted, etc.), the batch transfer will terminate. If Restricted, a file received in error will be unlinked (erased). EXAMPLE: rb -y Receive file(s) with YMODEM replacing old files, if any. EXAMPLE: rb -g Receive file(s) with YMODEM-g. Many programs claiming to support YMODEM actually use XMODEM with 1024 byte blocks; use YAM's sx -k, rx and rx -g XMODEM commands with these mutants. SEE ALSO: YMODEM protocol, Chapter 13. rb [-options] [dir] [file ...] Receives with options 1 or more files using YMODEM protocol. An optional disk and/or directory dir may be specified. The optional supplied pathnames file ... are used in place of pathnames normally provided by the sending program. If the sending program attempts to send more files than the number of names supplied to the rb command, the transfer is aborted. rc [-options] file Receives with options a single file using the Ward Christensen XMODEM protocol, 128 or 1024 byte blocks, and CRC-16 instead of an 8 bit checksum. YAM signals the sending program that CRC-16 is to be used. After four errors while attempting to receive the first sector, YAM will cancel the CRC-16 option and reverts to checksum operation. The probability of an undetected transmission error is much less if CRC-16 is used in place of the default 8 bit arithmetic checksum. (C) 1994 Omen Tech Inc Chapter 4 Selected Commands DSZ Manual Addendum Line Printer Draft Selected Commands 27 Omen Technology Incorporated Recommends use of the 16 bit CRC to maintain data integrity at professional levels. Chapter 20 describes the available options to the rc command. If Restricted, a file received in error will be deleted. EXAMPLE: rc foo.com SEE ALSO: XMODEM-CRC protocol, Chapter 13. ro [-options] file Receives with options a single file using non- standard XMODEM-CRC protocol logic. OverThruster(TM) speeds file downloads at the expense of error recovery. OverThruster operation is controlled by the O numeric parameter. As fans of Buckaroo Bonzai know, the OverThruster is not universally applicable. A transmission error will almost always terminate an OverThruster file download. If Restricted, a file received in error will be unlinked (erased). EXAMPLE: ro foo.com SEE ALSO: O numeric parameter rx [-options] file Receives with options a single file using the Ward Christensen XMODEM protocol. CRC-16 is not the default because most commercial comms programs only support the 8 bit checksum. Chapter 20 describes the available options. If Restricted, a file received in error will be unlinked (erased). EXAMPLE: rx foo.com The rc command should be used whenever possible instead of rx. EXAMPLE: rx -g foo.txt Receive a single file with an ACKless XMODEM protocol mutant incorrectly called "ymodem-g" by PCBoard and Qmodem programs. SEE ALSO: XMODEM protocol, Chapter 13. rz [-options] Receives with options 1 or more files using ZMODEM protocol. Chapter 20 describes the available options. Each file's pathname is obtained from the sending program. The +, a, b, n, N, r, and y options are accepted from the sending program, subject to Restriced privileges. If the +, b, n, N, r, or y option is specified to the receiver, it overrides any contrary options specified to the sender. Only one of the a, b, or r options may be specified. Only one of the +, n, N, or y options may be specified. If a file is received in error (retries exhausted, etc.), the batch transfer will terminate. If Restricted, a file received in error (C) 1994 Omen Tech Inc Chapter 4 Selected Commands DSZ Manual Addendum Line Printer Draft 28 Selected Commands will be unlinked (erased). EXAMPLE: rz -y SEE ALSO: Z term option SEE ALSO: ZMODEM protocol, Chapter 13. rz [-options] [dir] [file ...] Receives with options 1 or more files using ZMODEM protocol. An optional disk and/or directory dir may be specified. The optional supplied pathnames file ... are used in place of pathnames normally provided by the sending program. If the sending program attempts to send more files than the number of names supplied to the rz command, the transfer is aborted. To allow use of the rz command, Z term option (ZMODEM AutoDownload) should be turned off with a dis -Z command. sb [-options] [PREFIX=p | ONAME=x] pathspec Send the files specified in pathspec using True YMODEMTm Protocol. The pathname, length, and modification time of each file are transmitted. Files which cannot be opened are skipped. An empty pathspec sends all files in the current directory. A directory name expands to all regular files in that directory. If an error aborts a file transmission (retries exhausted, etc.), batch transfers terminate. The sb command will send files with SEAlink protocol if the receiving program requests SEAlink. EXAMPLE: sb -k *.com Sends *.com using 1024 byte packets. The receiver must be commanded to receive the files with an rb command. Unix and OS/2 users: sb command cannot be used to send source files that grow after the beginning of transmission. SEE ALSO: YMODEM protocol, Chapter 13, SEAlink protocol, Chapter 13. sx [-options] file Send a single file using the Ward Christensen XMODEM or XMODEM-CRC protocol. The receiving program may request use of a 16 bit CRC, which is more accurate than the default checksum. DOS/Unix files sent this way will have Control-Z (CPMEOF) garbage characters appended to make the file length a multiple of 128. EXAMPLE: sx foo.com EXAMPLE: sx -k foo.com Sends foo.com using 1024 byte blocks The receiver must be commanded to receive the file with an rx filename or rc filename command. (C) 1994 Omen Tech Inc Chapter 4 Selected Commands DSZ Manual Addendum Line Printer Draft Selected Commands 29 SEE ALSO: XMODEM, XMODEM-1k, XMODEM-CRC protocols, Chapter 13. sz [-options] [PREFIX=p | ONAME=x] pathspec Send the files specified in pathspec using ZMODEM Protocol.[2] If the remote supports ZMODEM AutoDownload, or accepts rz followed by carriage return as a command to receive files with ZMODEM protocol, only the sz command need be given. Otherwise, the receiver must be commanded to receive the files with an rz command or menu choice. The +, a, b, n, N, r, y, and Z options are sent to the receiving program. Only one of the a, b, or r options may be specified. Only one of the +, n, N, or y options may be specified. Each skipped file is counted as an error as indicated by the e test condition and e numeric parameter. If the q option is used, files skipped as a result of selective file transfers are not counted as errors. The pathname, length, and modification time of each file are transmitted. Files which cannot be opened are skipped. An empty pathspec sends all files in the current directory. A directory name expands to all regular files in that directory. If ONAME=x is given after the options (if any) and before the file name(s), x will be used exactly as given as the COMPLETE destination pathname instead of each file's actual pathname. It is the sender's responsibility to use lower case for x unless the filename is really supposed to be all caps. EXAMPLE: sz -y ONAME=B:/spiked/secret /soviet/sdi/newlaser.doc Results in the destination file secret on drive B: in the /spiked directory. (Destination directories must exist and be writable). If instead PREFIX=p is given after the options (if any) and before the file name(s), p will be added to the destination pathname(s) as a prefix. It is the sender's responsibility to use lower case for p unless the prefix is really supposed to be all caps. EXAMPLE: sz -y PREFIX=C:/foobaz/ /biff/bam/aardvark.wak Results in the destination file "C:/foobaz/aardvark.wak" EXAMPLE: sz *.com Sends all files with a .com extension. __________ 2. The receiver may use the sz command to send files by uploading an sz command with the zcommand command. (C) 1994 Omen Tech Inc Chapter 4 Selected Commands DSZ Manual Addendum Line Printer Draft 30 Selected Commands EXAMPLE: sz -r ??log Crash Recovery sends only the new data if the receiver has incomplete versions of these files. EXAMPLE: sz -fn src/*.c src/*.h maildir Sends only newer .c and .h files in the src subdirectory, and all new files in the maildir subdirectory. EXAMPLE: zcommand "sz -fn /bin /wp" commands a remote YAM system in Host Operation (unrestricted) to send all new files in the /bin and /wp directories. EXAMPLE: sz -Yn *.c Sends only newer versions of files that already exist at the destination. EXAMPLE: sz -Rf usera Sends all files in the usera directory and all subdirectories thereof. Directories are not sorted when the R option is used on 16 bit systems. SEE ALSO: ZMODEM protocol, Chapter 13, Options, Chapter 20. (C) 1994 Omen Tech Inc Chapter 4 Protocol File Transfer OPTIONS DSZ Manual Addendum Line Printer Draft Protocol File Transfer OPTIONS 31 5. Protocol File Transfer OPTIONS Options modify the way the protocol file transfer commands send and receive files. They are reset before each command line. The a, b, r and rr options are mutually exclusive. With ZMODEM, a b option given to the sender or receiver will override any a option. The +, c, r, rr, N, n, p, and y options are mutually exclusive. The Y option may be followed by the c, +, r, n, or N option. Specifying these options to the receiver overrides the ZMODEM sender's specification of these options. The DOS append command interferes with some of these options. + When receiving to a file already on disk, append the new data to the file. If the specified file does not exist, it is created. This option is not allowed if YAM is Restricted. EXAMPLE: rc -+ evrybody.dat When sending files with ZMODEM, the + option commands the receiver to append to a file already on the receiver's disk. EXAMPLE: sz -+ ONAME=master.log *.log sends all .log files in the current directory to be appended to master.log on the receiver's computer. NOTE: Append (+) is not the same as crash recovery (-r). Append is used to concatenate (add) new data to an existing file. The resulting file contains both old and new data. NOTE: If an append (+) file transfer is interrupted and restarted, data may be duplicated. SEE ALSO: r option 7 Strip data to 7 bits for file transfers with the Kermit protocol. Program executables and other 8 bit binary files cannot be sent this way. In the absence of the 7 option YAM transfers all 8 bits of each byte. If the communications line is set to 8 bits no parity, the 8th bit is transmitted, otherwise YAM requests 8th bit quoting. NOTE: The 7 option is distinct from the 7e and 7o term options. a (ASCII) The a option applies to files received with XMODEM, YMODEM, or ZMODEM protocol. It converts newlines not preceded by CR to CR/LF pairs. NULL, RUBOUT, and all characters in each packet beginning with Ctrl-Z are excluded. The a option is useful when receiving text files without carriage returns directly from Unix (C) 1994 Omen Tech Inc Chapter 5 Protocol File Transfer OPTIONS DSZ Manual Addendum Line Printer Draft 32 Protocol File Transfer OPTIONS systems. When sending with ZMODEM, the a option instructs the receiver to convert text files to the conventions used in its operating environment. When sending to VAX/VMS rz this selects CR carriage control variable length record format. The a option does not apply to the Kermit, sx, or sb commands. Files transferred with the a option cannot be processed with the ZMODEM r (recover/resume) option. EXAMPLE: rc -a program.c receives program.c and converts end of lines to CR/LF. b (Binary) With ZMODEM, inhibits the receiver from translating the file contents. If either the ZMODEM sender or receiver specifies b option, any contrary requests will be ignored. EXAMPLE: sz -b program.exe c With ZMODEM, change the file name to prevent collision if the destination file exists. The receiving program must support the ZMODEM c option or file disposition will be undefined. The form of the invented (changed) filename is implementation dependent. Use CRC-16 with the rx, rt, and r7 commands. e Normally, ZMODEM senders escape XON, XOFF, Ctrl-P, CR-@-CR, and Ctrl-X, and ZMODEM receivers ignore XON and XOFF. The e option escape all control characters when sending files with the ZMODEM protocol. In 7-bit environments, the e option also escapes RUBOUT (7F).[1] This option is useful when operating with brain damaged data PBX systems and other types of "front ends". SEE ALSO: zmtxesc, zmrxesc string parameters E With ZMODEM-90, force 8th bit encoding even if the transmission medium appears to support 8 bits.[2] f Send the full pathname as specified (exclusive of disk identifier) when using a batch send command. Normally only the file name __________ 1. In 7-bit environments, ZMODEM always escapes FF. 2. Not featured in DSZ.COM. (C) 1994 Omen Tech Inc Chapter 5 Protocol File Transfer OPTIONS DSZ Manual Addendum Line Printer Draft Protocol File Transfer OPTIONS 33 portion (without any directory prefix) is transmitted. The f option applies to batch file transmission with the kermit sb, sb, send, and sz commands. EXAMPLE: cd /src; sz -f robot/r2d2.h sends the file with the pathname robot/r2d2.h. EXAMPLE: sz -f /src/robot/vox/3tpi0.* SEE ALSO: PREFIX=p flag for the sb and sz commands. F Insert a pause after each transmitted data subpacket transmitted with ZMODEM. This is useful in certain situations when conventional flow control methods are unavailable, ineffective, or unreasonably slow (i.e., "broken"). The length of pause is set by the zmodem F numeric parameter. EXAMPLE: sz -F honker.dat SEE ALSO: zmodem F numeric parameter g Given to the receiving program, the g option to the rb command allows the sender and receiver to dispense with acknowledging each transmitted packet when using YMODEM batch transfers. YMODEM-g increases throughput when the transmitting medium itself (direct connection, X.PC session, or error correcting modems) provides error free transmission. The transmitting medium can use XOFF and XON to enforce flow control. If the transmitting medium does not enforce flow control,[3] the user must insure the receiver is not overrun. YAM on a PC or XT accepts data at 9600 bps without flow control when the file is being written to a hard disk or ramdisk.[4] If an error is detected when the g option is used, the transfer is aborted. EXAMPLE: rb -g __________ 3. X.PC automatically enforces end to end flow control. 4. Provided no memory resident programs or special drivers hog CPU cycles. (C) 1994 Omen Tech Inc Chapter 5 Protocol File Transfer OPTIONS DSZ Manual Addendum Line Printer Draft 34 Protocol File Transfer OPTIONS The g option may also be used with the rx command to receive files from Qmodem's G protocol. i With YMODEM or ZMODEM, instructs the receiver to write file(s) in stream oriented Image format. When sending to the VAX/VMS version of rz, the i option selects Stream_LF record format. Stream_LF preserves the exact contents of binary files read by VMS C programs. Stream_LF is useful for file servers and archives that service PCs, as well as C programs on VMS itself. (Without the i option, the VMS rz default is 512 byte fixed length record format.) I With YMODEM or ZMODEM, instructs the receiver to write file(s) in variable length binary record Image format. When sending to the VAX/VMS version of rz, the i option selects Variable length (mrs=510) binary record format. Certain programs such as Kermit32 understand this binary record format better than Stream_LF. k Use 1024 byte (1K) packets with the sb and sx commands. The default packet length is 128. This increases throughput when the speed is high relative to the response times of the communications channel and the computers. The k option is useful with 9600 or 19200 bps transfers with directly connected timesharing systems. The k option may not work properly uploading to some systems, particularly heavily loaded or poorly implemented timesharing systems at high speeds. The k option is valid only when sending to YAM, Unix rb, or other compatible programs. If the file length is not a multiple of 1024, the remainder of the file will be sent with 128 byte blocks. This option does not affect Kermit transfers. EXAMPLE: sb -k *.c *.h With the sz command, the k option forces an initial 1024 byte subpacket length. EXAMPLE: sz -k *.c *.h K Use 4096 byte (4k) packets with the sb and sx commands. The default packet length is 128. This increases throughput when the speed is high relative to the response times of the communications channel and the computers. The K option is useful with 9600 or 19200 bps transfers with directly connected timesharing systems. The K option may not work properly uploading to some systems, particularly heavily loaded or poorly implemented timesharing systems at high speeds. The K option is valid only when sending to compatible programs. If the file length is not a multiple of 4096, the remainder of the file will be sent with shorter blocks. This option is useful when working with non-ZMODEM programs that support the "XMODEM 4k" protocol, and for settling arguments. (C) 1994 Omen Tech Inc Chapter 5 Protocol File Transfer OPTIONS DSZ Manual Addendum Line Printer Draft Protocol File Transfer OPTIONS 35 EXAMPLE: sb -K *.c *.h l Force pathnames that are all uppercase to lower case. This option is reset by the call command. This option is ignored on DOS and OS/2 flavors of Pro-YAM. m (ZMODEM-90) Activate MobyTurbo(TM) for maximum throughput on compressed files sent over completely transparent connections. MobyTurbo can be used over links that support YMODEM-g. MobyTurbo can not be used with most forms of software flow control or over networks that reserve control characters. The m option can be given to either the sending or receiving ZMODEM-90 program. Likewise MobyKermit(TM) increases the speed of Kermit file transfers. Unlike ZMODEM, the Kermit m option can only be given to the sending program. Some Kermit programs do not work with the m option. M Locks out MobyTurbo even if the other program has given the m option. This option is useful if the transmission path does not support complete transparency. The Kermit receive M option causes unprefixed control characters to be ignored. This is useful in certain environments that insert spurious characters into Kermit packets. n (ZMODEM) Each file is transferred if the corresponding destination file does not exist, or if the source file is newer. The n option can be given with either the sz or rz commands. This option is not allowed if the receiver is Restricted. EXAMPLE: sz -n *.* attempts to send all files in the current directory. Only those files that do not exist in the destination directory, and those for which the source is newer will be sent. N (ZMODEM) Transfer the file if the corresponding destination file does not exist, or if the source file is newer or longer. The N option be used with the sz and rz commands. This option is not allowed if the receiver is Restricted. EXAMPLE: sz -N *.* p (ZMODEM) Protect destination file; bypass this file if it already exists on the destination system. P (ZMODEM-90) When transferring files over 7 bit paths, pack 4 8-bit bytes into 5 7-bit bytes for transmission instead of quoting the 8th bit.[5] This increases transmission speed on compressed files. (C) 1994 Omen Tech Inc Chapter 5 Protocol File Transfer OPTIONS DSZ Manual Addendum Line Printer Draft 36 Protocol File Transfer OPTIONS q (Quiet) suppresses block by block status line update during Kermit and X/YMODEM file transfers. Also prevents skipped files from incrementing the e numeric parameter and e test condition. r (ZMODEM) Resume/Recover an interrupted file transfer with the ZMODEM protocol. May be given with either the sz or rz commands. The r option may be used to resume the transmission of a long file after a disconnect or power loss, without having to start over at the beginning of the file. The r option may also be used when the source file grows from time to time and only the incremental portion needs to be sent. The r option assumes that the contents of the destination file are identical to the corresponding beginning portion of the source file. The r option should not be applied to a file that has been modified by the a option. This option is not allowed if the receiver is Restricted. EXAMPLE: sz -r hugefile.lst SEE ALSO: zmodem c numeric parameter For convenience, the r option can be specified on all files if desired, even those that have not been interrupted during a transfer. However, if you do make the r option the default with DSZOPT you could inadvertently overwrite valuable data with unrelated data from a random file with the same file name. The "ZMODEM Crash Recovery at NNNN" message may not appear when performing Crash Recovery on very short files. rr As above, but the files are compared by taking a 32 bit CRC on the contents before deciding on whether to start a fresh transfer. EXAMPLE: sz -rr maybenewer.lst With the -rr option, all of the files are compared or transmitted by default. The number of bytes used in the comparison may be restricted by setting the zmodem R numeric parameter to a number between 2048 and 32000 (1 billion on 32 bit flavors). EXAMPLE: zmodem pR20000 ______________________________________________________________________ 5. Not supported in DSZ.COM. (C) 1994 Omen Tech Inc Chapter 5 Protocol File Transfer OPTIONS DSZ Manual Addendum Line Printer Draft Protocol File Transfer OPTIONS 37 s SlugBait modifies the logic of ZMODEM sending to detect and report attempts at evading accountability for receiving files. Such attempts are flagged with a Q status in the log of sent files. SlugBait adds a slight delay to file transmission, and a transfer that is cut off at the very end of file may very infrequently be reported with Questionable instead of ERROR status. S When sending file(s) with ZMODEM, interrogate the receiving program for its serial number. S option terminates when a serial number is received or when the call command is given. Receiving file(s) with YMODEM or ZMODEM from programs providing a serial number also provides the other program's serial number. The serial number received is listed by the performance log. t Enter the term function after file transfer(s) complete. The t option should not be used in commands given from within the term function, either directly or with soft key definitions. u Unlink (remove, delete) the file after it has been sent with the sz command. Users should not manually skip or abort transfers when this option is used. v View the data being transmitted or received. Only correct data is displayed. Viewing standard ASCII files does not interfere with correct transmission at high speeds, although throughput may be degraded. The output may be redirected to a capture file or DOS device with the > or >> command. Unless output is redirected, this option must not be used when YAM is in Host Operation. When invoking Unix Pro-YAM as xyam, rz, sz, rb, sb, rx, or sx, creates a logging file with information useful for debugging purposes. More v's create more detailed debugging information. SEE ALSO: v numeric parameter, LOGFILE environment variable wN Use a window size of N bytes with the sz command, overriding the zmodem w numeric parameter. If N is missing, use a ZMODEM window size of 4096 bytes. SEE ALSO: Flow Control Chapter 14, zmodem w numeric parameter WN Request the sending program to use a window size of N bytes, overriding the sender's window size setting, 4096 bytes if N is missing.[6] (C) 1994 Omen Tech Inc Chapter 5 Protocol File Transfer OPTIONS DSZ Manual Addendum Line Printer Draft 38 Protocol File Transfer OPTIONS y Yes it is OK to replace a file already on disk when receiving a file. If absent, the operator is given a choice of appending to the current file (a), erasing it (y) or aborting (n). This option is not allowed if YAM is Restricted. When sending with ZMODEM, commands the receiver to replace a file on its disk. Y (ZMODEM) Transfer only those files for which a file with the same pathname exists at the destination, overwriting the destination files. The Y option may be followed by other ZMODEM options to further qualify the selection of files to transfer. This option is not allowed if YAM is Restricted. EXAMPLE: sz -Yn *.* If the source directory contains files A, B, and C, each dated today, and the destination directory contains B and C, with B a week old and C dated today, only B will be sent. zT Use T minutes behind GMT (Greenwich Mean Time) as the local timezone instead of the z parameter value for the file(s) transferred with this command. EXAMPLE: sb -k -z300 ESTfile sends ESTfile corrected for creation in Eastern Standard Time. Z Transmit files with compression. The ZMODEM receiver must indicate its ability to decompress received files for this option to take effect. When sending between Unix systems, files are compressed with 12 bit Lempel-Ziv compression. Otherwise, packets are transmitted with Run Length Encoding. Over slow channels, compression increases the transmission speed of compiler listings, screen dumps, etc. by up to 50 per cent. LZW compression is more effective on more types of data than RLE compression. Some files, including the Personal Computing Magazine ASCII Test File, speed up by more than an order of magnitude with either RLE or LZW compression. Heavily encrypted data and compressed files, including ARC and ZOO archives, do not benefit from ZMODEM compression. The situation with fast compressed modems is more complex. The benefits of ZMODEM compression will depend on the particular ______________________________________________________________________ 6. The W option is supported when receiving files from ZMODEM-90(TM) program versions after Jan 21 1990. (C) 1994 Omen Tech Inc Chapter 5 Protocol File Transfer OPTIONS DSZ Manual Addendum Line Printer Draft Protocol File Transfer OPTIONS 39 application; try the transfers with and without ZMODEM compression to determine the most efficient options. (C) 1994 Omen Tech Inc Chapter 5 Numeric Parameters DSZ Manual Addendum Line Printer Draft 40 Numeric Parameters 6. NUMERIC PARAMETERS O Controls OverThruster(TM) operation with the ro command (XMODEM, XMODEM-1k, and YMODEM) downloads. This parameter should be set as follows: CompuServe XMODEM Negative numbers control the number of bytes added to the window on XMODEM downloads from the CompuServe Information Service. Larger numbers increase throughput, but cause improperly interfaced MNP modems on CIS nodes to drop characters under stress, disrupting the file transfer. EXAMPLE: dsz pO-512 ro file1.ext Other XMODEM Positive numbers up to a system dependent value less than the protocol block size increase throughput. Larger values induce timeouts and/or retransmitted blocks. The optimum value must be determined by experiment. 30 to 60 gives best results with MNP modems at 2400 bps. The optimum value varies depending on the remote computer, modem(s), system traffic, and the network node. Performance improvement with high O parameter values is greater with sluggish networks. EXAMPLE: dsz pO60 ro file1.ext EXAMPLE: dsz pO1000 rb -o (EXEC-BBS, MNP 5, 9600 bps) 6.1 X/Y/ZMODEM Numeric Parameters These parameters control XMODEM, YMODEM, and ZMODEM protocol transfers. They are set with the z px# command available with ZMODEM flavors of YAM. EXAMPLE: z pl16384 Forces ZMODEM packet length of 16384 (default packet length is infinite). Their current values can be displayed with a z p command. These parameters rarely need changing in normal environments. b If non zero, ZMODEM sends a break when it is sending a file and receives a retransmission request. This mode of operation may be used with high speed modems to clear unwanted characters from the modem's buffer during error recovery. Usually, the modem must be given a configuration command to make it clear its transmit buffer when receiving a break signal. B Sets the duration of the break signal in tenths of a second, default 2 (200 milliseconds). (C) 1994 Omen Tech Inc Chapter 6 Numeric Parameters DSZ Manual Addendum Line Printer Draft Numeric Parameters 41 c Enables Cybernetic Data Recovery(TM) on XMODEM and YMODEM transfers. Setting this parameter to 0 accommodates programs with non standard XMODEM/YMODEM protocols and slightly quickens file transfers. The default value of 1 provides optimum reliability for XMODEM and YMODEM transfers with programs that meet the XMODEM/YMODEM spec. Setting this parameter to -1 disables error checking provided by the r option. e If non zero, escape all control characters. This allows ZMODEM transfers to operate over data PBX and other systems that freak out when they receive control characters. d Some operating systems, most notably VAX/VMS, use ^X to stop programs. ZMODEM uploads consist of a "rz" command to start the rz program followed by a ZMODEM packet. If the ^X in the ZMODEM packet causes problems, the zmodem d parameter can be used to delay the initial ZMODEM packet until the rz program initializes itself. The zmodem d parameter sets a delay in tenths of a second on ZMODEM sends (uploads) between the "rz" command and the first packet. f Flow control mask, only used with Unix/Xenix systems. Setting this to 0 (the default) disables hardware (RTS/CTS) flow control for Xenix/Unix systems with broken hardware flow control. On Xenix/Unix systems where only CTS flow control works properly, set this to 8192 to allow CTS flow control only. Use 32768 for newer SCO systems that support CRTSFL. F Sets the pause after each data subpacket sent with the sz command when the F option is used, or when failing flow control is detected. The default value of 1 causes a one tenth second delay. SEE ALSO: F option On some Unix operating systems the pause will be rounded up to the next second or two. J See discussion of the zmodem k parameter immediately below. k (PCDOS versions only) On YMODEM and ZMODEM downloads, the zmodem k parameter causes YAM to pause transmission every k kilobytes by asserting flow control restraint, and flushing disk writes. This does no require any special cooperation from the sending program beyond properly configured flow control. If the zmodem k parameter is non zero and the B numeric parameter is set, flushing is performed every B bytes. The zmodem J parameter controls the time delay between flow control assertion and buffer flushing. The zmodem K parameter controls the time delay between buffer flushing and the de-assertion of flow control. (C) 1994 Omen Tech Inc Chapter 6 Numeric Parameters DSZ Manual Addendum Line Printer Draft 42 Numeric Parameters SEE ALSO: B numeric parameter, Error Messages chapter (interrupt latency) K See discussion of the zmodem k parameter immediately above. l Normally, the ZMODEM "packet length" ("block length") is the file length. Setting this parameter non zero forces ZMODEM to close a frame and wait for an ACK after each # bytes (default 0). This makes ZMODEM behave like XMODEM, YMODEM, or JMODEM, which wait after each block/packet for an acknowledgement before going on to the next block. The packet length may be adjusted to prevent buffer overflow in data PBX systems. The call command resets this parameter to 0. L (Default 0) If non zero, overrides the nominal length of data subpackets within each ZMODEM frame. A smaller value speeds error recovery on noisy lines, a large value (maximum 1024) reduces the overhead of CRC characters. The call command resets this parameter to 0. Please note that streaming ZMODEM has no direct equivalent to XMODEM/YMODEM/JMODEM block length unless the zmodem l parameter is set non zero. In the absence of errors, ZMODEM normally sends the entire file without pause. If somebody claims ZMODEM's 1024 byte subpacket length is slowing things down by more than one half per cent, he doesn't understand ZMODEM and should be ignored. n Sets the number of NULLS (default 0) sent before each ZDATA frame. Some buffered modems (Fastcomm) have a firmware bug which loses characters when changing the direction of transmission. This causes data frames to fail with a CRC or other error. ZMODEM n parameter values in the range of 100 to 150 have obviated this syndrome. P When set to 2 (the default), purge the transmit buffer and force a receiver response when a CR/LF sequence (indicating a PC-Pursuit DATA LOSS message) is detected. A value of 1 does not purge the transmit buffer. A value of 0 disables special processing of CR/LF sequences received by the sending ZMODEM. w If non 0, restrict the ZMODEM transmit window to the specified number of bytes. Setting this parameter to N requests acknowledgements from the receiver every N/4 characters. Pro-YAM then waits for acknowledgements from the receiver whenever it has sent N more characters than it has received acknowledgements for. This parameter is useful with networks with defective flow control. Error recovery when ZMODEM is used with networks that store an excessive number of characters in transit can usually be improved by restricting the window size. The call command resets this parameter to 0. Setting this parameter non zero also causes the sz command to perform an extra step that actively prevents an ALT-F given to a (C) 1994 Omen Tech Inc Chapter 6 Numeric Parameters DSZ Manual Addendum Line Printer Draft Numeric Parameters 43 receiver from generating a spurious successful file transfer completion. W Adjusts the number of characters the ZMODEM receiver will silently ignore when searching for the beginning of a new frame. This may be set larger to accomodate networks with excessive in transit storage, smaller to speed error recovery from long error bursts on direct connections. The call command resets this parameter to the default (1400). Z Number of minutes (default 0) to adjust the file modification date when using the Telink or Clink/SEAlink file transfer protocol to transfer a file between different time zones. The timeout parameters below may be set lower for faster X/YMODEM error recovery when transferring files between two micros, higher to accomodate extremely sluggish systems. Only in pathological cases is it necessary to modify these parameters. The call command resets these parameter to their defaults. p Timeout in tenths of seconds for gaps within a packet (default 100). r If non zero, remove incomplete files received with a protocol except those received with the + option (default 0). R When non 0, limits the number of bytes of file comparision used with the sz and rz -rr option. This parameter may be set to a value between 2048 and 32000 (1 billion on 32 bit systems). This parameter is given to the receiving program. EXAMPLE: z pR30000 SEE ALSO: -rr option s Timeout interval in seconds waiting for XON characters or positive flow control (default 15). If an XON is not received within this time, transmission resumes anyway. A value of 0 disables this timeout. t XMODEM, YMODEM, and ZMODEM Receiver timeout in tenths of seconds waiting for a packet or command acknowledgement (default 100). T Transmitter timeout in tenths of seconds waiting for a packet (default 600). / ==|-- == \ == == [][][] (C) 1994 Omen Tech Inc Chapter 6 Numeric Parameters DSZ Manual Addendum Line Printer Draft 44 Numeric Parameters "I don't know what this thing does, but it's pointing in your direction." -Dr. Who, from A Usenet Signature (C) 1994 Omen Tech Inc Chapter 6 Hardware Compatibility DSZ Manual Addendum Line Printer Draft Hardware Compatibility 45 7. HARDWARE/SOFTWARE COMPATIBILITY 7.1 Hardware Compatibility Notes IBM PS/2 Model 50Z Early samples of this machine have a design error on the motherboard that causes comms programs to lock up the machine. Replacing the motherboard with a correctly functioning unit from current production corrects the problem. The part number of the replacement PS2/50 Z motherboard is 35F5928. (Information provided by John M. Choma 73047,3566) In the U.S. IBM has stonewalled on this issue, but in December 1988 agreed to replace the defective motherboards under warranty. Zenith Computers Older Zenith computers may need a ROM update to work properly with interrupt driven programs such as YAM. NEC Multispeed The NEC Multispeed computer locks up unless STACKS is set in CONFIG.SYS. In addition, one should disable floppy disk power save mode, and set popup program memory allocation to 0. For best results, use the latest NEC software patches to the NEC MSDOS, and/or use an IBM PC-DOS instead of the DOS supplied by NEC. EGA/VGA Multimode Boards Some multimode EGA and VGA boards include an "auto select" feature designed to configure the board to various display standards using software trickery. In the case of Paradise VGA and others, this feature causes excessive interrupt latency and loss of data at high speeds. Disabling the auto select on the display board corrects this problem. EGA Wonder The BIOS in the ATI EGA Wonder has been observed to increase interrupt latency to the dismay of 9600 bps operation on an 8 mHz no wait state AT clone. There has also been a report (unexplained) that an EGA board has induced line noise in one instance. Tecmar Graphics Master To use YAM with this display board, give a mode mono command before running Pro-YAM. Leading Edge MODEMS and I/O BOARDS Some Leading Edge modems and interface boards use 8250 UART devices that do not respond correctly when the software turns the transmitter interrupts on and off. High performance communications programs such as Professional-YAM require properly functioning UART chips, such as the National Semiconductor 16450 or 16550A. (C) 1994 Omen Tech Inc Chapter 7 Hardware Compatibility DSZ Manual Addendum Line Printer Draft 46 Hardware Compatibility 7.2 Brain Damaged UARTS Omen Technology has received reports of problems with buggy 8250 type UART integrated circuits in Leading Edge modem boards, serial port interfaces, and computers. The defective chip logic affects high performance software. Replacing the buggy chip with a newer chip (NS16550AFN) corrects the problem. The UM82450 chip in the Zoom 2400HC also appears to cause problems. Zoom Telephonics advises that this problem is limited to their old model. The old model has an external volume control. You can identify an old chip by inspecting the serial interface board for 8250 or UM82450 type devices. A service technician or hardware hacker can help if you are not familiar with reading chip numbers. Dsz users can identify old chips with the following software command: EXAMPLE: dsz port 1 speed 2400 p The resulting value for the P numeric parameter should be 1. A value of 0 indicates a non-buffered chip or a chip with a defective buffer. ZCOMM and Professional-YAM users can look at the printout produced by the s command; old UART chips register as TYP 0. Some internal modems and PCMCIA cards use a firmware simulated UART that is not detected as a buffered UART. Properly designed firmware UARTs provide excellent buffering. The National Semiconductor NS16550AFN is a pin compatible plug in replacement for 8250 and 16450 serial chips. Omen Technology PCDOS software enables the FIFO buffer in the NS16550AFN to prevents loss of data from poorly written device drivers, TSR programs, etc. We are also using the Goldstar GM82C550 chip with a 9025 date code. This Goldstar chip is plug compatible with the National chips. No problems have been discovered with this chip. The NS16550AFN has better electrical characteristics than the older UART chips. 386 and fast 286 machines should use the NS16550AFN for best results. Omen Technology software has been written to allow time for the older UART chips to operate. However, there is a limit to how much the software can rearrange chip accesses without resorting to performance robbing wait loops. Some other software is not as forgiving of slow chips. Fortunately the FIFO UART chip situation continues to improve. As of this writing, the following plug compatible chips are known to work. (C) 1994 Omen Tech Inc Chapter 7 Hardware Compatibility DSZ Manual Addendum Line Printer Draft Hardware Compatibility 47 + Goldstar GM82C550, + National Semiconductor NS16550AN and NS16550AFN + Startech 16550 Current Western Digital WD16C550 chips do not function properly at low speeds. The Startech 16C552 contains two UARTS and a buffered parallel interface. If your UART chip is soldered in or otherwise not replaceable, you will need a new plug-in board with a good UART chip. Byte Runner Technologies 800-274-7897 offers a variety of boards and chips. Another is the KW-524E-1 Serial/Parallel/Game card, $30.90 from TSD Systems, 800-331-9130 (FAX 407-331-8130). A board populated with two FIFO UARTS is $41.85. The Hayes ESP board comes with two serial ports with NS16550AFN devices. The ESP definitions for COM3 and COM4 agree with the industry standard definitions used by Omen Technology. All option switches on the ESP board should be OFF except those used to select the port number (COMn). The $99 "WinSport II" from Boffin LTD 612-894-0595 has two NS16550AFN FIFO UARTS and also supports MobyBaud (18.432 MHz clock). This card also supports higher IRQ numbers, freeing up the low IRQs for other applications. Software Electronics 503-640-1946 sells a $59 board with two FIFO UARTS and a bidirectional enhanced parallel port. The following information comes from a number of people: "I have located a small dealer in New York who has the cards with or without the 16550. I believe the price is around $50.00. The company is RJK Consulting and the number is 718-968-9167. The gentleman to speak to is a Mr. RJ Kulman. ... I got this information off the "Interlink" BBS system." Fm: Nick Braak [TRICON] 75156,1254 Fry's - 415-770-FRYS. This is a Silicon Valley electronic department store. Jameco Electronics at 415-592-8097 800-538-5000 sells National NS16550AFN chips mail order (credit card) in small quantities. Unfortunately, we received a number of reports (none recently) that their serial i/o card was supplied with the defective WD16C550 soldered in, even when ordered with specific instructions to include 16550AFN chips. (C) 1994 Omen Tech Inc Chapter 7 Hardware Compatibility DSZ Manual Addendum Line Printer Draft 48 Hardware Compatibility TSD Systems advertise a 2 serial/parallel/game card with one or two NS16550-AFN chips. 800-331-9130(voice) 407-331-8130(fax) Microprocessors Unlimited, 24000 South Peoria, Beggs, OK. (918) 267- 4961. The price for the chip is $13.50 plus shipping costs. Consolidated Computers 4 Shoppers Lane Suite 121 Turnersville, NJ 08012 (609)751-9595(voice) (609)751-3843(bbs) (609)751-3840(fax) Arrow Electronics at 800-932-7769 (516-467-1000). Willies Computer Software Company: 800/835-4832. N.B.: Current Western Digital WD16C550 chips do not function properly at low speeds. This has been confirmed with samples received directly from Western Digital. WD is aware of this problem, but has not informed us of a corrected chip. 7.3 Software Compatibility Some programs and device drivers affecting the operation of PC-DOS may interfere with YAM, especially when YAM is operating at high baud rates. Historically, loss and corruption of data have been caused by memory resident programs. Some of these programs increase interrupt latency preventing YAM from reading a character from the UART holding register before the next character comes in on top of it. In other cases, programs do not properly restore the state of the machine when they exit from interrupts. If such a problem is suspected, run YAM without any memory resident programs or special drivers to locate the source of the problem. Once the offending program is identified, a call to the program's vendor may obtain a corrected version. The design of memory resident programs is a little known black art. Subtle bugs, non reproducible interactions, and magic combinations are commonplace results of attempts to impose various aspects of multitasking on top of an operating system that was not properly designed to permit such extensions. Omen Technology Incorporated may be able to help identify these interactions if provided with the source code of the offending programs. Some of the known troublemakers are mentioned below. Smartdrive This disk cache program (Windows 3.1 version) has been observed to cause communications errors even when a FIFO UART is used. BREAK ON This DOS command causes ^C to be intercepted by DOS at various, sometimes awkward, times. BREAK ON must be used with (C) 1994 Omen Tech Inc Chapter 7 Software Compatibility DSZ Manual Addendum Line Printer Draft Software Compatibility 49 extreme caution as interrupting most programs with ^C compromises the integrity of the file system. If a program is interrupted by ^C or Ctrl-Break, the file system should be immediately checked with CHKDSK. In some cases it may be necessary to reboot DOS with Ctrl- Alt-Del if DOS runs out of file descriptors. A synonym for BREAK ON might be NUKE FILESYSTEM ON. Someday MicroSoft may discover what to do with ^C (DEC figured it out about two decades ago). In the meantime, we recommend you not use it. When Professional-YAM starts up, it stores the status of the BREAK ON flag, then clears it. On Exit, or when calling a DOS program, YAM restores the BREAK ON flag to its previous state. Disk Cache Programs Microsoft SMARTDRVIVE Norton NCACHE Multisoft PCQWIK Many disk cache programs tie up the computer long enough to lose modem data. (It only takes a few thousandths of a second!) Some disk cache programs are worse than others. Some are so bad not even a FIFO UART can overcome them. Some programs (SMARTDRV) can be set to cache disk reads only, avoiding the delayed writes that disrupt file downloads. Mouse Drivers Some mouse drivers have been reported to interfere with file transfers. DOS append command The DOS append command allows one or more directories to be partially "grafted on" to a specified directory. Some DOS system calls "see" files in the new directory, some do not. This interferes with file transfer options such as -y, -r and -n. If the DOS append command must be used, use the /x:on switch. TOPDOS TOPDOS, ver 2.00i by Frontrunner Development Corp., has caused ZCOMM and other programs to lock up. Disabling TOPDOS restores normal operation. DOS 3.2 DOS 3.2 introduces the concept of a fixed number of interrupt stacks. The default value chosen is not always sufficient, and DOS 3.2 sometimes prints the infamous Internal Stack Failure message and cheerfully halts the computer. Adding the line STACKS=20,128 to the CONFIG.SYS file should correct the problem. Lacking any useful documentation from Microsoft, you may wish to experiment with different values. Extended Memory RAMDISKS Extended Memory electronic disks (ramdisks) require the 80286 chip to switch in and out of protected mode during block transfers. A hardware reset pulse is used to switch back to the "real mode" required for DOS. This causes loss of modem data at high speeds. It may be possible to reduce excessive interrupt latency by reducing the length of protected mode block transfers to 128 or less. In one (C) 1994 Omen Tech Inc Chapter 7 Software Compatibility DSZ Manual Addendum Line Printer Draft 50 Software Compatibility instance, replacing the ROM BIOS with a newer version increased the maximum transmission speed without losing characters to 9600 bps. This problem has not been observed with expanded memory (Intel/Lotus/AST/etc.) ramdisks. The new generation NS16550AN or 82510 serial interface circuits should be used instead of 8250's for best results at high speed. The NS16550AN allows operation at a communications speed of 115200 bps compared to 9600 bps (typical) for the 8250 and 16450. Disk Drivers Disk drivers, especially hard disk drivers for 80286 machines, lock out interrupts for varying periods of time. The actual interrupt latency depends on the speed of the computer and the particular BIOS code used. In one case, upgrading to a newer BIOS allowed operation at 38400 bps, compared to 4800 bps previously. Such an improvement is well worth the small ($25 typical) cost of a new set of ROM BIOS chips. DOS 3.x Each new version of PC-DOS adds new features and eats up more of the 8088's meager resources. DOS 3.2 increases interrupt latency enough to interfere with YAM's operation at 19200 bps on an IBM PC. If this is a problem, switching to DOS 2.1 will reduce the interrupt latency. Replacing 8250 and 16450 serial interface chips with the new NS16550AN chip allows YAM to operate smoothly at high speeds. FANSI-Console Versions of this program before 1.07 did not maintain the pointer to the active display board in the IBM documented memory location. A DOS mode command may cause YAM to reference the wrong display adapter address. This caused incorrect sync signals and possible damage to certain monitors. Current versions (2.X) increase interrupt latency enough that the serial line drops characters when the keyboard is touched. Seaware Batch Versions of this program has been known to cause loss of data. Spotlight/Lotus Metro This TSR program has been reported to cause Pro-YAM to lock up. Pathname Modifiers Programs such as FILEPATH and GLOBALS allow files to be visible in more than one directory at a time. Such programs may interfere with security when YAM is restricted, since that security is based on restricting access to directories. In general, sensitive files should not be made global when YAM is made accessible to outside callers. Pro-YAM may not recognize file names generated by such programs unless the program traps the DOS FINDFIRST calls as well as the file open calls. (C) 1994 Omen Tech Inc Chapter 7 Software Compatibility DSZ Manual Addendum Line Printer Draft Software Compatibility 51 We have received various reports of strange behavior which have been traced to filesystem modifications caused by such programs, including damaged file systems. We recommend such programs be phased out as soon as possible, as they may not operate at all with future versions of DOS or distributed file systems. BRKBOX This program locks out interrupts up to 17 milliseconds while waiting for the vertical retrace. For a communications program, 17 milliseconds is a very long time, and data will be lost at speeds above 300 bps. CGCLOCK Programs such as CGCLOCK.COM use clock interrupts to update a time display on the screen. Some increase interrupt latency so much that YAM cannot respond in time to accept characters from the remote, even at 1200 baud. Concurrent PC-DOS YAM runs under Version 4.1 of Digital Research Concurrent PC-DOS (CPCDOS). The - numeric parameter must be set to 0. The CPCDOS "addmem" command should be used to allocate extra memory if DOS Gateway are to be used. ANSI.SYS YAM uses direct keyboard input from the ROM BIOS because the DOS keyboard input calls do not handle Ctrl-BREAK properly. As a side effect, keyboard keys redefined by ANSI.SYS have no effect on YAM's operation. It is possible to program some of the keys to call YAM with arguments. The following file, reassigns ALT-C, ALT-H, and ALT-V to execute the commands shown below. The $ character represents ESCAPE. $[0;46;"cd \tmp";13;"YAM call -200 cbbs-r";13p $[0;35;"YAM call host";13p $[0;47;"cd \tmp";13;"YAM call cissig";13p YAM uses the ROM BIOS CRT functions and direct output to the display, bypassing any processing provided by ANSI.SYS. Perhaps someday Microsoft will enhance ANSI.SYS to make it useful for programs like YAM ... PRINT.COM Once the DOS PRINT program is memory resident, file downloads at high speeds (38kb on a PC) suffer from interference, even if a file is not currently being printed. With certain printers, the DOS PRINT command will preempt the running program for several seconds at a time. These "swapouts" can be confusing when you are accessing an interactive application. They may interfere with file transfers, especially if the remote program uses "tight" timing. If this happens, PRINT should be suspended during file transfers. Operation of the PRINT command does not appear to cause loss of data downloaded from timesharing services at 1200 bps, as long as the interruptions last less than ten seconds. Perhaps IBM or Microsoft will someday fix this bug in (C) 1994 Omen Tech Inc Chapter 7 Software Compatibility DSZ Manual Addendum Line Printer Draft 52 Software Compatibility the DOS PRINT command. PRINT should not be invoked from YAM for the first time as DOS memory allocation will become fragmented. If PRINT or some other spooler is outputting to a serial port using the BIOS INT 14h serial port driver, YAM's "!~subprogram" command will redirect the printer output to the remote and thus should be avoided. SWITCHAR = - YAM will work properly when the DOS switch character is set to "-", allowing Unix style pathnames. The - numeric parameter must be set non zero to allow YAM DOS Gateway to use / to delimit directories. It may be necessary to remove this line from CONFIG.SYS and reboot DOS before using the IBM dump and restore commands. N.B.: DOS 3.0 does not support SWITCHAR in the config.sys file. A short program, DASH, will set switchar to -. It prevents many oaths. Microsoft has removed all SWITCHAR support in DOS 5.0. So much for POSIX compliance. This manual is Copyright 1994 Omen Technology Incorporated, All Rights Reserved. It was formatted 9-19-94. (C) 1994 Omen Tech Inc Chapter 7 Software Compatibility DSZ Manual Addendum Line Printer Draft Software Compatibility 53 8. CROSS REFERENCE INDEX (C) 1994 Omen Tech Inc Chapter 8 Software Compatibility Chuck Forsberg 8. CROSS REFERENCE INDEX (C) 1994 Omen Tech Inc Chapter 8 Cross Reference Index Version 18.15 TurboDial 2.41 Line Printer Draft Cross Reference Index 4 kb packet length 34 FIDO 26, 28, 43 50Z 45 file date 5, 11 7 bit data 31 file download 16, 16 80286 50 file name override 26, 28 8250 UART 46 file transfer 26, 26, 27, 28, 29 ANSI.SYS 51 file transfer packet length 34, append 31 34 append DOS command 31, 49 Flow Control 20, 24, 33, 37, 40, batch file transfer 26, 27, 28, 42, 43 29 frame length 42 baud rate 51 front end 32 BIX Timesharing Service 19 GEnie 18 Block length 7, 42 graphic file transfer display 3 Break 40 handshake 20 BREAK ON 48 handshake command 23 Byte Information Exchange 19 hard disk 50 Cache, disk 49 Hayes ESP board 47 carrier detect 23, 25 IBM PS/2 Model 50Z 45 Clear to Send 23, 24 image option 34 Clink 26, 28, 43 interrupt latency 41, 49, 51 collision 32 Kermit 9, 35 comm port 24 Lempel-Ziv 38 compression 7, 38 Lotus Metro 50 CompuServe 27 LZW 38 Concurrent PC-DOS 51 minirb program 16 control character escaping 32 MobyKermit 35 CPCDOS 51 MobyTurbo 6 CPMEOF 12, 12, 28 modem port 24, 25 CR 16, 31 MODEM protocol 27, 28 Crash Recovery 5 Mouse Drivers 49 CRC-16 26, 28, 32 Multispeed 45 CTS 23, 24 NEC Multispeed 45 Cybernetic Data Recovery 41 networks 8 data overruns 41 newline 31 data PBX 32 no carrier detect 23, 25 Data Set Ready 23 ONAME= 28, 29 date stamping 5, 11 options 26, 26, 27, 28, 29, 31 DCD 23 overruns 41 delete 37, 38 OverThruster 11, 13, 27 directory specification 26 packet length 42, 42 disk cache 49 PAD 21 DOS 3.2 49, 50 pathname override 26, 28 DOS append command 31, 49 pathname, full 32 DSR 23 pathnames, received 26, 27 EGA Auto-select 45 pathnames, transmitted 28, 29 Emacs 20 PBX, data 42 erase 38 PC Pursuit 21 estimate command 23 PC-Pursuit 42 Extended memory 49 Performance log 37 FANSI-Console 50 port command 24 Fastcomm 42 portx command 25 (C) 1994 Omen Tech Inc Chapter 8 Cross Reference Index Version 18.15 TurboDial 2.41 Line Printer Draft Cross Reference Index PREFIX= 28 XMODEM 12, 12, 20 PREFIX=p 29 XMODEM Protocol 27, 28 printer spoolers 51 XMODEM-1k 12 Qmodem-G 14, 34 XMODEM-4k 34 RAMDISK 49 XMODEM-CRC 12 rb command 26 XOFF 20, 43 rc command 26 XON 20 Relaxed XMODEM 13 YMODEM 10, 14, 20, 26, 28 Relaxed YMODEM 13 YMODEM-4k 34 remove 37 YMODEM-g 9, 13, 26, 27, 33 RLE compression 38 Zenith 45 rlogin 8 ZMODEM 4, 8, 27, 28, 31, 35, 38, ro command 27 40 rx command 27 ZMODEM protocol 29 rz command 27 sb command 28 SCRtoPS 3 SEAlink 26, 28, 43 security 26, 28 Serial Number 37 SlugBait 37 Smartdrive 48 Spotlight 50 STACKS= 49 Stream_LF record format 34 Streaming XMODEM 14 Subpacket length 7 SWITCHAR 52 sx command 28 sz command 29 TCP/IP 8 Telenet 21 Telink 43 telnet 8, 15 term function 37 TERMINAL SERVERS 8 Thedraw 3 time zone 5, 11 Timing 43 TOPDOS 49 transparency 32 Unix 15 unlink 37 VAX/VMS 17 VDISK.SYS 49 VGA Auto-select 45 view 37 VMS 17, 34 VMS Stream_LF record format 34 window size 21, 37, 42 X.PC 11, 13, 33 (C) 1994 Omen Tech Inc Chapter 8 Cross Reference Index