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

[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.

[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.

[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...

[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.

[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.

[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.

[Alastair]

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?

[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.

[Rolo]

Thanks, Tormod, I'll check that out. Maybe I can get one rom or another working.

[Rolo]

And thanks Alastair, too, of course. Yes, that list is abolutely helpful too.