cartreader icon indicating copy to clipboard operation
cartreader copied to clipboard

Atari Interactive cartridge don't produce valid dumps

Open smesgr9000 opened this issue 8 months ago • 1 comments

OSCR firmware version

14.5

OSCR hardware version

HW5 Rev1

Attach OSCR_LOG.txt file here

No response

System used

Atari 2600

Describe the issue.

It seems (all?) bank switching carts of Atari Interactive releases have few bytes which are read differently to AtariMax.

The RealSports collection for example with retail 1980th releases are matched by stella to known dumps with AtariMax. While OSSC for example only got Baseball (got lucky?) and Volleyball (not a bank switching game).

I think the issue has something to do with the cart layout. I assume all carts are always F4 (aka 32kB) with odd or duplicate data in the unused banks. Thus reading bank switch area will do stupid things.

As a workaround:

  • dump twice using F4
  • discard the first dump (-> currently I'm not sure why this is needed likely some reset is missing)
  • split the second dump in 4k chunks than combine the good banks into a file. With that the RealSports games dump fine. I will retest the other cartridges later this week

-> We could change the F6 & F8 code to use the same logic as F4 but I'm not sure what side effect this could have for older bank switching cartridges :(

@sakman55 do you have an opinion? @PsyK0p4T @PsychoFox11 If I remember correctly at least one of you had this issue. Sorry if I'm wrong.

smesgr9000 avatar May 21 '25 17:05 smesgr9000

I have tested several other games. Berzerk Enhanced - is still different but it is a F4 game - so maybe something else is going on Mr. Run & Jump - don't have this issue but bank switching area of every bank is identical for this game. Caverns of Mars - think workaround do work here too

smesgr9000 avatar May 24 '25 09:05 smesgr9000