194 lines
7.9 KiB
Plaintext
194 lines
7.9 KiB
Plaintext
How to Back-up your PC *VisiCalc disk
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_____________________________________
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How to Back-up your PC *VisiCalc disk
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Dual drive disk copy procedure:
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The following technique will convert your Visicalc disk to a normal,
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copyable disk. But don't try to add other files to the disk as there are
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copyable
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four programs on the disk which do not appear in the directory. Use of
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this procedure does not relieve you of your responsibilities under copy-
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right laws or licensing agreements. Using a PCDOS disk on drive A:,
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Format a new disk on B:, then type what is underlined:
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_____
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A>DEBUG
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As soon as DEBUG is loaded, remove the PCDOS disk from A:. Insert your
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write-protected, "copy-protected" VisiCalc Disk in A: If you have at
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least 96kb of memory, type what is underlined:
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____________
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-L 100 0 0 80 (reads first 16 tracks from A:)
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_____________
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-L 100 0 80 80 (reads next 16 tracks from A:)
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_____________
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-W 100 1 80 80 (writes same on B:)
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______________
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-L 100 0 100 3E (copies the last 8 tracks except
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______________
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-W 100 1 100 3E for the "uncopyable" sector 13F)
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If you have less than 96KB, you must take smaller bites. Type the
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following instead:
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____________
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-L 100 0 0 40 (read a 32KB "gulp", 8 tracks)
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____________
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-W 100 1 0 40
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_____________
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-L 100 0 40 40
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_____________
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-W 100 1 40 40
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_____________
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-L 100 0 80 40
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_____________
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-W 100 1 80 40
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_____________
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-L 100 0 C0 40
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_____________
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-W 100 1 C0 40
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______________
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-L 100 0 100 3E
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______________
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-W 100 1 100 3E
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Remove your old VisiCalc disk from A:. You have now copied the disk, but
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it won't run yet. First you must patch the 80-column VisiCalc program
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loader/decrypter so that it will run correctly with sector 13F formatted
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normally. type:
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_____________
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-L 100 1 138 3 (load the invisible loader-decrypter)
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___________
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-E 150 90 90 (first patch for 80-col.)
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________
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-E 156 B0
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___________
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-E 158 90 90
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____________________
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-E 168 90 04 40 90 90
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___________
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-E 16E C6 06
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___________
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-E 173 90 90
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____________________
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-E 179 90 04 20 90 90
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___________
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-E 17F C6 06
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___________
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-E 184 90 90
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____________________
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-E 18A 90 04 00 90 90
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___________
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-E 190 C6 06
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________
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-E 195 EB
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____________________
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-E 1B0 90 05 00 00 90 (last patch disables timer check)
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_____________
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-W 100 1 138 3 (save it back on new disk)
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VisiCalc Backup 8-1-82 JEH Page 1
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VisiCalc Backup 8-1-82 JEH Page 2
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Next, you must apply the following patches if you wish to be able to run
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VCONFIG to select the 40 column display, type:
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_____________
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-L 100 1 13B 3 (load 40-col loader-decrypter)
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__________________________
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-E 14D 90 90 B4 10 90 90 90 (first patch)
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___________
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-E 169 C6 06
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___________
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-E 16E 90 90
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____________________
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-E 174 90 2C 20 90 90
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___________
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-E 17A C6 06
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___________
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-E 17F 90 90
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____________________
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-E 185 90 2C 00 90 90
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___________
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-E 18B C6 06
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________
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-E 190 EB
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____________________
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-E 1AB 90 04 00 90 90 (disable timer check here too)
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_____________
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-W 100 1 13B 3 (save on new disk)
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_
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-Q (exit debug)
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Remove your new copyable VisiCalc disk from B:. Write-protect the new
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copy, place it in A: and boot it. After you have verified that the copy
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works correctly, you may copy it using "DISKCOPY". All copies of the new
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disk should function exactly as the original "copy-protected" disk. The
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serial number is unchanged. You may not legally sell, give or loan either
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the original disks, copies, or documentation!
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Single drive note:
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_
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All DEBUG accesses to drive A: (L 100 0 x x) refer to the original
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_
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VisiCalc disk. References to drive B: (W 100 1 x x) refer to the new disk
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being prepared. Make sure that you swap disks at the right time and that
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your original disk has the write-protect tab installed.
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Conversion to .COM file - single drive, 48KB minimum:
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_____________________________________________________
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Conversion to .COM file - single drive, 48KB minimum:
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The following procedure will read the 80-column VisiCalc program from your
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Visicalc disk (original or copy) and write a standard .COM file which may
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be loaded on a non-standard disk drive (Winchester, double-sided, 8",
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etc.). You will need another formatted disk. This disk should contain
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the DOS system files (format /s) and any .BAT file (required to exit
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VisiCalc sometimes). With a DOS disk in A:, type:
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_____
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A>DEBUG
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Remove the DOS disk, insert your VisiCalc disk, then type:
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_____________
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-L 100 0 138 3 (load the VC80 loader/decrypter)
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____________
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-M 0 3FF 7000 (duplicate it in higher memory)
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____
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-R CS (inspect command segment register)
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DEBUG will respond with the contents of the CS register (049F for DOS 1.0,
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4B5 FOR DOS 1.1) and prompt with a colon :. Type the old contents + 700
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(hex). That is, 0B9F or BB5. Do the same with RS. The screen should
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appear as on the next page.
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VisiCalc Backup 8-1-82 JEH Page 2
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VisiCalc Backup 8-1-82 JEH Page 3
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A>DEBUG
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_____________
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-L 100 0 138 3
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____________
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-M 0 3FF 7000
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____
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-R CS
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CS 049F or CS 04B5 for DOS 1.1
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____ ____
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:0B9F or :0BB5
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____
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-R DS
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DS 049F or DS 04B5
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____ ____
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:0B9F or :0BB5
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Next, apply the following patches, type:
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___________
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-E 107 9F 04 (byte-flipped 049f from CS if DOS 1.0)
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or
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___________
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-E 107 B5 04 (if DOS 1.1, byte-flipped 04b5)
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_________________
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-E 24D BB A8 00 90 (hard-wire the decryption key)
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Now, to run the loader/decrypter, type:
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__________
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-G =1B8 26B (execute from 1b8 to 26b)
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The entire program will now be loaded and decrypted and a register dump
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should appear on the screen. Next restore CS and DS to their previous
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values and set the file length in CX. The screen image should appear as:
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(register dump)
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____
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-R CS
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CS 0B9F or CS 0BB5 for DOS 1.1
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____ ____
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:049F or :04B5
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____
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-R DS
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DS 0B9F or DS 0BB5
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____ ____
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:049F or :04B5
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____
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-R CX
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CX 0000
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____ ____
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:6B64 (length = 6B64 FOR VisiCalc 1.1, 6802 for VC 1.0)
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All that is left is to name the file, write it and exit. Remove the
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VisiCalc disk, insert the new, formatted, empty disk in the same drive and
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type:
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________
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-N VC.COM (or whatever you wish to name it)
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_
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-W (write the .COM file)
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_
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-Q (exit DEBUG)
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THAT'S IT!
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This document was placed in the public domain by me on August 1, 1982. I
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do not know how many different "copy-protection" methods might be in use,
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but this worked on my disk and should work on yours until VisiCorp changes
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their recipe. Please feel free to distribute this information without
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charge to any interested person.
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John Hart
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Houston, Texas
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*VisiCalc is a trademark of VisiCorp (formerly Personal Software).
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VisiCalc Backup 8-1-82 JEH Page 3
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iCalc is a trademark of VisiCorp (formerly Personal |