Apple II Madness (Apple II Demos)

[ac.tomo]

3 hours ago, ac.tomo said:

Many thanks Usotsuki, that's just the ticket.

What I'd like to do now is dis-assemble the 3d demo to a text file, but to do that I need to know where the data and the code is situated. I have this table, how accurate it is I'm not sure:

 

$7000 SIN/COS TABLE

$7200 POINT & LINE DATA

$7400 SHAPE TABLE

$7A00 MULTI-PLICATION DATA

$8200 PROJECTION TABLE

But, I don't know where the main code sits. Any help much appreciated. If you require a link to the 'wire-graphic' source code, or the disk image for the full solid graphic images just ask.

 

NB* I also understand that you can dis-assemble memory to a TeXT file in the debugger using the MD command, but does anyone know exactly how?

 

Perhaps a rough memory map might be useful; maybe if someone could tell me the ROM addresses, BASIC, program memory etc., that would be great.

[potatohead]

https://github.com/Michaelangel007/dcc6502

 

That will disassemble large programs.  There are other tools out there.  In general, reverse engineering is best done on a modern environment.  You get the code into a binary file and begin to pick it apart.

 

The Apple 2 will disassemble with its built in monitor too:

 

http://wiki.apple2.org/index.php?title=System_Monitor

 

Way back in the day, loading things into memory and looking at them with the monitor is how many people would begin the task you are.

 

In general, you have a nice hint with the table info you have.

 

I would start by looking at jumps.  Program flow.  You can map a lot of it that way.

 

Then keep parsing.  The Apple soft switches are good too.  Searching for access to them may reveal initial code, for example.

 

 

[potatohead]

http://www.kreativekorp.com/miscpages/a2info/memorymap.shtml

 

 

[ac.tomo]

Thankyou for them links, but I cant make head or tail of the 1st two, the 3rd is very useful, thankyou.

[potatohead]

Try 

 

CALL -151 [enter]

 

D000L [enter]

 

That will launch the monitor and disassemble memory starting at $D000

 

From there, you need to start reading up on tools to examine machine code.  It is a non trivial task.

 

 

 

 

 

 

[ac.tomo]

thankyou potatohead.

[ac.tomo]

On 10/24/2020 at 12:02 AM, ac.tomo said:

 

I typed this program into the apple basic screen and it does exactly what I need, but how can I print the dis-assembly to a text format file?

Lastly, if I load the 3d demo, and then load up the MASTER file (BASIC I presume) will the 3d demo still be in the memory?

 

 

On 10/24/2020 at 12:31 AM, The Usotsuki said:

Probably; BASIC programs load from 0801 by default.

 

If you want it to write to a text file on disk, change 40-50 to

40 INPUT "FILENAME: ";F$

50 PRINT:PRINT CHR$(4)"OPEN"F$:PRINT CHR$(4)"WRITE"F$

and 90 to

90 PRINT:PRINT CHR$(4)"CLOSE"

 

 

I typed in this program (to save to file), but I am getting error #9, break in 50. Sometimes it occurs straight away, othertimes after a short period, any advise?

 

Edited October 25, 2020 by ac.tomo

[The Usotsuki]

Error 9 is Disk Full.

[ac.tomo]

Hmmm... that's odd. Perhaps you can help me direct the file to a particular folder.