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Text File | 1990-01-01 | 13.8 KB | 318 lines

NoFlop Version 1.00 Fixed Disk Boot Utility for floppy disks Shareware (C)Copyright 1990 by Jerry Locke INTRODUCTION When you use DOS's Format command to initialize a new disk, it is created with a boot sector containing a routine which reads the rest of DOS into memory if the disk is booted in drive A. This is obviously useless if you did not use the /S parameter to format the disk as a system disk, and produces the following message if it is booted in drive A: Non-system disk or disk error Replace and strike any key when ready NoFlop will make your floppies more friendly by "zapping" the boot sector with a replacement routine which reads the first sector of your hard disk and then executes it. The practical use for this is that you can leave the disk in the drive and still boot from the hard disk. The reasons you might need your floppies to be in drive A and still boot from the hard disk are varied. For example, I use pcANYWHERE (product of Dynamic Microprocessor Associates Inc.) to access my computer at the office from home. If I need something from a floppy I just leave it in the drive. Imagine my frustration if the power glitched and the machine sat at the "Non-system disk" prompt all weekend while I was trying to call! After executing NoFlop on all my non-bootable floppies, there is no problem if the machine reboots for some reason. SYSTEM REQUIREMENTS NoFlop requires a PC-compatible computer running DOS 2.00 or later with a hard disk drive. COMMAND SYNTAX The syntax for NoFlop is as follows: NOFLOP [Enter] No parameters are required or accepted. The diskette in drive A will be patched with the NoFlop boot code. If the drive is empty, disk write protected, etc., appropriate messages will be provided. NoFlop Version 1.00 Page 2 WARNING! WARNING! WARNING! DO NOT use NoFlop with copy protected diskettes! Whatever was in the boot sector (which is probably vital to the operation of the diskette) will be gone, FOREVER. For the same reason, do not use NoFlop on bootable system diskettes. NoFlop Version 1.00 Page 3 REGISTRATION AND LEGAL JARGON If you think NoFlop is of value, you should register your copy. Registration is MANDATORY for commercial or corporate use. When you have registered, you will be entitled to the following: 1) The next version (1.10), when available. 2) Complete commented source code on diskette. 3) Phone support. 4) Peace of mind for having done the right thing. To register, please send twenty dollars ($20) to the author at the address on the next page, and specify what size diskette you need. The source code is NOT shareware; you may NOT distribute it. For the protection of the author's rights, certain safeguards have been built into NoFlop to protect against unauthorized changes. Such modifications may result in "License violated" errors, which can be corrected by using an unaltered copy of the program. Note that there is no protection against changes made to a diskette processed by NoFlop, however. If you get a "License expired" error, don't panic! If you are a registered user, you already have a newer version. If you're not, the newest version is available to you either the same place you got this one, or one of the following BBS systems: Byte Junction Pep's Data System PKWARE Support BBS Mobile, Alabama Mobile, Alabama Glendale, Wisconsin 205 866-7895 205 626-7447 414 352-3670 ------------------ -------------------- ---------------------- The best message 9600 VSM, CD ROM! From the PKZIP author! base in the state! 300+ megs of d-load! Need I say more? NoFlop is SHAREWARE. You are free to use, copy and distribute it for NONCOMMERCIAL use if: 1) No fee is charged for use, copying or distribution. 2) Only the original, unmodified NOFLPxxx.ZIP file is distributed. Clubs and user groups may charge a nominal fee, not to exceed $10, for expenses and handling. If you got NoFlop on a disk you bought from a "$5 a disk" shareware distributor, you are NOT registered; what you paid for is their handling expenses. You still should register. NoFlop Version 1.00 Page 4 DISCLAIMER The author hereby disclaims all warranties relating to this software, whether express or implied, including without limitation any implied warranties of merchantability or fitness for a particular purpose. The author will not be liable for any special, incidental, consequential, indirect or similar damages due to loss of data or any other reason, even if the author or an agent of the author has been advised of the possibility of such damages. In no event shall the author's liability for any damages ever exceed the price paid for the license to use the software, regardless of the form of the claim. The person using the software bears all risk as to its quality and performance. The huge paragraph above does not mean I won't fix real problems if they occur! If you find bugs in NoFlop, please inform me. I'll fix them! In addition, the first person to report what I consider to be a valid bug gets a free registration and mention of their name in the next version of the program documentation. Note: The definition of what constitutes a "valid" bug is totally determined by the author. AUTHOR INFORMATION NoFlop is written and supported by: Jerry Locke 115 Baldwin Road Satsuma, AL 36572 205 675-8283 All inquiries and registrations should be directed to this address, or to me on one of the two Alabama BBS's listed on page 3. NoFlop Version 1.00 Page 5 NoFlop Technical Information 1: ERRORLEVELS The program returns standard DOS "errorlevels" for Disk Controller Status, for use within batch files. The possible values are as follows: 0 - Normal successful completion. (Yay!) 1 - Illegal command to driver 2 - Address Mark not found (bad sector) 3 - Write Protected Disk 4 - Sector not found (reformat!) 6 - Diskette change line active (disks were switched) 8 - DMA overrun 9 - DMA attempt over 64K boundary 12 - Invalid media 16 - CRC error on disk read 32 - Controller error 64 - Seek failure 128 - Disk time out (drive not ready) 255 - Bad DOS version or License Violation If one of the more obscure errors occurs, you will get "Disk Error xxH ????ing drive A" message, where xxH is the hexadecimal error number and ????ing is either reading or writing. Most of them you can safely expect never to see. Normally, you should be concerned with only 0 or not 0 (i.e. either success or failure) as all other statuses indicate that the program did not run successfully. An example batch file to format and then NoFlop a disk is as follows: @ECHO OFF FORMAT A: %1 %2 %3 %4 %5 %6 %7 %8 %9 IF EXIST A:\IBMBIO.COM GOTO END IF EXIST A:\IO.SYS GOTO END :DOIT! NOFLOP IF ERRORLEVEL 255 GOTO BADDOS IF ERRORLEVEL 4 GOTO FAILED IF ERRORLEVEL 3 GOTO WRITPROT <-- Normally, this should never IF ERRORLEVEL 1 GOTO FAILED happen--we just formatted a ECHO Done! write protected disk?! GOTO END :WRITPROT ECHO Disk is write protected! Fix it and press Enter. PAUSE >NUL GOTO DOIT! :BADDOS ECHO Either upgrade your DOS or call Jerry Locke! GOTO END :FAILED ECHO Invalid media, Sector not found, etc ... NoFlop failed! :END The second line of the batch file does a FORMAT with all command line switches preserved. The third and fourth lines prevent NoFlop from destroying a bootable disk (it was formatted with /S). NoFlop Version 1.00 Page 6 2: PATCHES If you are adventurous and wish to make alterations to the way NoFlop works, there are three fields which can be easily modified through DEBUG or with a file editor such as Norton Utilities. The first field defines the size of the boot BIOS Parameter Block (BPB) area and is located at offset 28 hexadecimal in the .COM file. Because there are varying types and sizes of disks (360K, 720K, etc.), we cannot safely overwrite the boot sector and assume a particular type of disk. The BPB area (which defines the number of heads, tracks, sectors, etc.) must be retained in the new boot sector. The value at 28 hex determines how long this area is. The current value, 3B hex, is valid through DOS 4.01; future versions may require modification here to a larger value. One program available, INVIS-I-DISK, provides retention of the BPB but only keeps 36 bytes of it, causing DOS 4.0 to have problems with disks. Another, BOOTTHRU, assumes that the target is a 360K 5.25 inch floppy and proceeds to destroy any other type of disk. The second modifiable field defines the number of retries (plus 1) for the initial disk read. During beta testing, it was discovered that certain computers would return a controller error 6 (change line active) instead of valid boot sector data, thus scrambling the disk when it was written back. (Don't panic! In the version of NoFlop you have, this bug has been thoroughly squashed!) The byte is at offset 29 hex and has a value of 4, indicating 3 retries. Finally, you can modify the drive number for NoFlop to alter. The locations are at A9 hex and D8 hex, both with a value of 0, which normally specifies drive A:, physical drive 0. If you have other drives attached which you need to access with NoFlop, you can change these locations to specify the new drive. You must change both! For example, you might have an external floppy drive that is designated as C:; you would change both locations from 0 to 2. Never, ever, specify a value greater than 80 hex. To do so would overwrite a hard disk's partition table, rendering the entire disk useless! Note that these locations are valid only for version 1.00 of NoFlop and will undoubtedly change in future versions. You may also wish to change the text messages at 196 hex and 1D8 hex from "A" to the new drive. 3: PROCESSES The actual operation of NoFlop is a three step process. First, the existing boot sector is read into memory from physical drive 00 (the first floppy). Second, the BPB information is transferred from there to the new boot sector area of memory. Finally, the new boot sector is written, again to physical drive 00. If you have differring requirements, or requests for enhancements to NoFlop, please contact the author by mail. NoFlop Version 1.00 Page 7 4: REVISION HISTORY and BUG SPOTTERS: 0.90 - 12-11-89 Original Beta test version. 0.91 - 12-12-89 Retry count, error messages added. 0.92 - 12-15-89 Unauthorized modifications detection added 0.93 - 12-18-89 Suggested by John Hassell; Mobile, Alabama: Use checksumming to make sure boot sector is not corrupted. Used DOS int 21.9 instead of int 10 so output can be redirected or piped. Documentation created. --------------------------------------------------------------- 1.00 - 01-01-90 Initial public release, expires 01-01-92 Suggested by Pepper Myers (Sysop of Pep's Data System, Mobile, AL - 205 626-7447): Included documentation on how to modify the drive specification.