How to Back-up your PC VisiCalc disk How to Back-up your PC VisiCalc disk Dual drive disk

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How to Back-up your PC *VisiCalc disk _____________________________________ How to Back-up your PC *VisiCalc disk Dual drive disk copy procedure: The following technique will convert your Visicalc disk to a normal, copyable disk. But don't try to add other files to the disk as there are copyable four programs on the disk which do not appear in the directory. Use of this procedure does not relieve you of your responsibilities under copy- right laws or licensing agreements. Using a PCDOS disk on drive A:, Format a new disk on B:, then type what is underlined: _____A>DEBUG As soon as DEBUG is loaded, remove the PCDOS disk from A:. Insert your write-protected, "copy-protected" VisiCalc Disk in A: If you have at least 96kb of memory, type what is underlined: ____________-L 100 0 0 80 (reads first 16 tracks from A:) _____________-L 100 0 80 80 (reads next 16 tracks from A:) _____________-W 100 1 80 80 (writes same on B:) ______________-L 100 0 100 3E (copies the last 8 tracks except ______________-W 100 1 100 3E for the "uncopyable" sector 13F) If you have less than 96KB, you must take smaller bites. Type the following instead: ____________-L 100 0 0 40 (read a 32KB "gulp", 8 tracks) ____________-W 100 1 0 40 _____________-L 100 0 40 40 _____________-W 100 1 40 40 _____________-L 100 0 80 40 _____________-W 100 1 80 40 _____________-L 100 0 C0 40 _____________-W 100 1 C0 40 ______________-L 100 0 100 3E ______________-W 100 1 100 3E Remove your old VisiCalc disk from A:. You have now copied the disk, but it won't run yet. First you must patch the 80-column VisiCalc program loader/decrypter so that it will run correctly with sector 13F formatted normally. type: _____________-L 100 1 138 3 (load the invisible loader-decrypter) ___________-E 150 90 90 (first patch for 80-col.) ________-E 156 B0 ___________-E 158 90 90 ____________________-E 168 90 04 40 90 90 ___________-E 16E C6 06 ___________-E 173 90 90 ____________________-E 179 90 04 20 90 90 ___________-E 17F C6 06 ___________-E 184 90 90 ____________________-E 18A 90 04 00 90 90 ___________-E 190 C6 06 ________-E 195 EB ____________________-E 1B0 90 05 00 00 90 (last patch disables timer check) _____________-W 100 1 138 3 (save it back on new disk) VisiCalc Backup 8-1-82 JEH Page 1 VisiCalc Backup 8-1-82 JEH Page 2 Next, you must apply the following patches if you wish to be able to run VCONFIG to select the 40 column display, type: _____________-L 100 1 13B 3 (load 40-col loader-decrypter) __________________________-E 14D 90 90 B4 10 90 90 90 (first patch) ___________-E 169 C6 06 ___________-E 16E 90 90 ____________________-E 174 90 2C 20 90 90 ___________-E 17A C6 06 ___________-E 17F 90 90 ____________________-E 185 90 2C 00 90 90 ___________-E 18B C6 06 ________-E 190 EB ____________________-E 1AB 90 04 00 90 90 (disable timer check here too) _____________-W 100 1 13B 3 (save on new disk) _-Q (exit debug) 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


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