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Text File | 1987-10-08 | 4.7 KB | 101 lines | [TEXT/MPS ] |
- Implementation Notes:
-
- Program: MiniTerm -- a simple terminal emulation program.
- Written in MPW C v2.0
-
- Author : Jerry LeVan
- 325 Boone Trail
- Richmond Ky 40475
- June 3,1987
-
- Version 2: Oct 9,1987
-
- In order to build the application simply create a folder in the MPW
- folder and move the sources into the new folder. Use the enclosed
- "Make" file (MiniTerm.mak) to generate the necessary build commands.
- (or just use the Build command)
-
- Initial Modem settings:
- 1200 baud, 8 bit data, one stop bit, no parity and the modem port
- is used. The port can be changed to the printer port by holding down
- the mouse key during the launch. A popup menu will appear and the
- user can then choose a port to attach to. The baud menu can be used
- to set the speed. Permanent changes require program modification.
- (The program was designed to satisfy my immediate needs.)
-
- Xmodem notes.
- The Program supports three variations of the Xmodem protocol.
- a) MacBinary (the protection bit is never turned on)
- b) Text ( only text files may be sent/received and lf's, nulls,
- and ctlZ's are stripped on reception.
- lfs are added after cr's on transmission.)
- c) Straight (only text files are sent / received, on reception data
- is written as received into the data fork of the log
- file.)
-
- Xon/Xoff flow control is by default enabled,however during an Xmodem
- transfer flow control is turned off and upon completion is returned
- to its state before the transmission.
-
- The default error correction is CCITT CRC (actually it is inverted
- from the data communications standard since the Xmodem protocol
- specifies transmission of the most signicant bit first). On reception
- the CRC invitation will be offered three times and if not ACK'ed
- error correction will default to checksum. If you wish CRC's can
- be disabled, however at low speeds (1200 Baud) the difference is not
- worth the peace of mind that CRC checking provides. There is an
- option "Fast Down Load" that can be selected. This protocol delivers
- error detection but no error correction. The basic idea is that as
- soon as a packet has been received it will be ACK'ed so that the other
- end can immediately start sending the next packet while the current
- packet is being checked for validity. If an error is discovered the
- transmission will be aborted. I would not reccommend this method unless
- you are running at a very high baud rate over a "noise free" connection.
-
- The user of the program can chose to use 1024 byte buffers (the
- default of course is 128). This choice is only useful for very
- high speed connections. If the transfer is MacBinary the first block
- only contains the 128 byte MacBinary header. While this is wasteful
- its very easy to implement (just change the value of sectorSize).
-
-
- Since heirarchial and popup menus are used it is essential that
- system file 4.1 or greater be used. During initializtion the program
- checks for the existence of the PopUpMenuSelect trap and if not
- present the program will gracefully terminate.
-
- This program has not been extensively tested but appears to be fairly
- reliable and the Xmodem transfers are very fast. My vax 730 allows
- transfer rates at 103 to 105 bytes/second at 1200 baud (with CRC).
- MacPaint takes less than 20 seconds to transfer at 56KB (checksum,1024
- byte buffers and fast down load options).
-
- Version 2 additions:
-
- Version 2 offers a limited vt102 emulation. The main part of the
- emulation comes from Columbia Universitys's Kermit. Any flaws where
- probally induced by my modifications. I could not find a copyright
- notice in the code but I suspect that there may be some rights reserved
- by Columbia University. My keyboard mapping is a total kludge. I have
- only tested the program on a Mac Plus. All of the Dec Utilities seem
- to function properly.(ie edit phone mail monitor etc...)
-
- I have completely rewritten the Dialer module. This module has no
- global variables and easily be ported to other applications needing
- a dialer.
-
- This version of Miniterm introduces Paced Uploads. The User can specify
- a "pacing" character and a delay between characters. The program
- checks to see if there is a pace character on the current line prior
- to sending the next line.
-
- Users can now specify blink/nonblinking, block/underline, or visible
- /invisible cursor.
-
- One novelty of this program is the ability to "see" control characters.
- If Interpret Controls is not checked all control characters are
- displayed on the screen. This feature is especially helpful when
- trying to debug protocol problems.
-
- Caveat: This is an experimental program. My main desire is to understand
- how emulators work in the Macintosh environment.