Remove your new copyable VisiCalc disk from B:. Write-protect the new
copy, place it in A: and boot it. After you have verified that the copy
works correctly, you may copy it using "DISKCOPY". All copies of the new
disk should function exactly as the original "copy-protected" disk. The
serial number is unchanged. You may not legally sell, give or loan either
the original disks, copies, or documentation!
Single drive note:
_All DEBUG accesses to drive A: (L 100 0 x x) refer to the original
_VisiCalc disk. References to drive B: (W 100 1 x x) refer to the new disk
being prepared. Make sure that you swap disks at the right time and that
your original disk has the write-protect tab installed.
Conversion to .COM file - single drive, 48KB minimum:_____________________________________________________Conversion to .COM file - single drive, 48KB minimum:
The following procedure will read the 80-column VisiCalc program from your
Visicalc disk (original or copy) and write a standard .COM file which may
be loaded on a non-standard disk drive (Winchester, double-sided, 8",
etc.). You will need another formatted disk. This disk should contain
the DOS system files (format /s) and any .BAT file (required to exit
VisiCalc sometimes). With a DOS disk in A:, type:
_____A>DEBUG
Remove the DOS disk, insert your VisiCalc disk, then type:
_____________-L 100 0 138 3 (load the VC80 loader/decrypter)
____________-M 0 3FF 7000 (duplicate it in higher memory)
____-R CS (inspect command segment register)
DEBUG will respond with the contents of the CS register (049F for DOS 1.0,
4B5 FOR DOS 1.1) and prompt with a colon :. Type the old contents + 700
(hex). That is, 0B9F or BB5. Do the same with RS. The screen should
appear as on the next page.
VisiCalc Backup 8-1-82 JEH Page 2
VisiCalc Backup 8-1-82 JEH Page 3
A>DEBUG
_____________-L 100 0 138 3
____________-M 0 3FF 7000
____-R CS
CS 049F or CS 04B5 for DOS 1.1
____ ____:0B9F or :0BB5
____-R DS
DS 049F or DS 04B5
____ ____:0B9F or :0BB5
Next, apply the following patches, type:
___________-E 107 9F 04 (byte-flipped 049f from CS if DOS 1.0)
or
___________-E 107 B5 04 (if DOS 1.1, byte-flipped 04b5)
_________________-E 24D BB A8 00 90 (hard-wire the decryption key)
Now, to run the loader/decrypter, type:
__________-G =1B8 26B (execute from 1b8 to 26b)
The entire program will now be loaded and decrypted and a register dump
should appear on the screen. Next restore CS and DS to their previous
values and set the file length in CX. The screen image should appear as:
(register dump)
____-R CS
CS 0B9F or CS 0BB5 for DOS 1.1
____ ____:049F or :04B5
____-R DS
DS 0B9F or DS 0BB5
____ ____:049F or :04B5
____-R CX
CX 0000
____ ____:6B64 (length = 6B64 FOR VisiCalc 1.1, 6802 for VC 1.0)
All that is left is to name the file, write it and exit. Remove the
VisiCalc disk, insert the new, formatted, empty disk in the same drive and
type:
________-N VC.COM (or whatever you wish to name it)
_-W (write the .COM file)
_-Q (exit DEBUG)
THAT'S IT!
This document was placed in the public domain by me on August 1, 1982. I
do not know how many different "copy-protection" methods might be in use,
but this worked on my disk and should work on yours until VisiCorp changes
their recipe. Please feel free to distribute this information without
charge to any interested person.
John Hart
Houston, Texas
*VisiCalc is a trademark of VisiCorp (formerly Personal Software).
VisiCalc Backup 8-1-82 JEH Page 3
iCalc is a trademark of VisiCorp (formerly Personal