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CoCo cartridge Atom (1983) (26-3149) (Tandy)

Posted: Sun Jul 07, 2013 8:24 pm
by Rolo
download/rom/CoCo/Atom (1983) (26-3149) (Tandy).rom:
It looks like that rom in reality is just an 8k rom. It contains two concatenated copies of the game ($000 ... $1fff and $2000 ... $3fff).
I cut off the upper half and tried it. Game seems to run flawlessly.

Re: CoCo cartridge Atom (1983) (26-3149) (Tandy)

Posted: Fri Jul 12, 2013 10:28 pm
by Rolo
Game seems to run flawlessly.
No, it does not. Title screen and "intro" are ok. When I start the game play, the upper half of the screen fills with garbage. The lower half shows running counters and something moving. Graphics error or a special graphics mode?
Same with XROAR, same with original rom and 8k version.

Re: CoCo cartridge Atom (1983) (26-3149) (Tandy)

Posted: Sat Jul 13, 2013 7:27 am
by sixxie
Looks like you found one that calls directly into ROM!

Code: Select all

ce53| bda976      JSR     $a976               cc=d0 a=01 b=00 dp=00 x=0cfe y=0000 u=d295 s=3fd9
Enable sound on the CoCo, but on the Dragon ends up in the middle of a routine to set the video mode...

Re: CoCo cartridge Atom (1983) (26-3149) (Tandy)

Posted: Sat Jul 13, 2013 2:04 pm
by tormod
For Dragon, "Audio on" is at $bac5.

Tormod

PS. I have made a long list of Coco-Dragon ROM equivalents I should publish somewhere.

Re: CoCo cartridge Atom (1983) (26-3149) (Tandy)

Posted: Mon Jul 15, 2013 8:22 pm
by Rolo
Thanks tormod,
I changed the address of the JSR and cut off the upper 8k. The modified image now runs with xroar.
I'll try tomorrow on real hardware with my multi-cart.

Re: CoCo cartridge Atom (1983) (26-3149) (Tandy)

Posted: Sun Jul 21, 2013 12:30 pm
by Rolo
No, there are more rom calls.
Gameplay starts, but the resolution seems to switch into a wrong mode. Eventually the program freezes. My hex editor showed some more JSRs and JMPs into rom. A few more changes are required. Does anybody know a complete documented rom listing for kernal and Basic, like those we know for Commodore or Apple II?
Tormod, you're list really could be helpful, if you found it.

Re: CoCo cartridge Atom (1983) (26-3149) (Tandy)

Posted: Sun Jul 21, 2013 11:44 pm
by Alastair
Rolo wrote:Does anybody know a complete documented rom listing for kernal and Basic, like those we know for Commodore or Apple II?
Are any of the files at Graham's Dragon Page of use?

Re: CoCo cartridge Atom (1983) (26-3149) (Tandy)

Posted: Mon Jul 22, 2013 8:06 pm
by tormod
Rolo, I dumped my list here: http://archive.worldofdragon.org/index. ... quivalents

It is focused on I/O, parsing and printing and not (yet) much graphics or sound though. Commented CoCo ROM disassemblies can be found in the Toolshed software repository and in the "Unravelled" book series. I used that and a Dragon 64 ROM disassembly to find the equivalents, starting off with the information on Graham's pages. The code is very often identical, just shuffled around in different location and order.

EDIT: Added all from Graham's list.

Re: CoCo cartridge Atom (1983) (26-3149) (Tandy)

Posted: Mon Jul 22, 2013 8:26 pm
by Rolo
Thanks, Tormod, I'll check that out. Maybe I can get one rom or another working.

Re: CoCo cartridge Atom (1983) (26-3149) (Tandy)

Posted: Mon Jul 22, 2013 8:55 pm
by Rolo
And thanks Alastair, too, of course. Yes, that list is abolutely helpful too.