VisiCalc

Dear All,

In response to Tim McNemey’s request on comp.sys.apple2 dated 28/1/2009, please find in that disk image the following data:

- ROOT FOLDER
Two disk images VISICALC.DSK and VISICALC16.DSK. The disassembly has been performed from VISICALC.DSK.

- ORIGINAL
The original binary programs VC/80 1 and VC/80 2 as well as some basic disassembly parts that helped in generating the final disassembly.

- DISASSEMBLY
The “real” program disassembly. The Merlin source codes have been generated with The Flaming Bird Disassembler which is by far the best Apple IIgs disassembler out there. Download the disassembly in PDF format:

PROGRAM INFORMATION
- $0000..$00FF: zero page
- $0200..$03FF: some basic routines
- $0800..$6FFF: the real program
Data of the program is set for a 40-col display with no Videx card.
The entry point of the program is $5A37.
There are many routines which use the stack pointer thus that has generated a lot of DB $xx in the code (e.g. JSR $2905, JSR $63B9)
In such routines, I believe there are pointers, note that I have not declared them as “DA”.
All texts end with the high-bit set, therefore texts have been declared as “DCI”.
A RWTS is included in the $6xxx RAM area, please pay attention to the $6D00..$6FFF RAM area which seems to be shared with the program.

CONCLUSION
That is a raw disassembly, those who will comment the source will have a huge work, I wish them good luck ;-)

Antoine Vignau
Brutal Deluxe Software

http://www.brutal-deluxe.fr/