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Source Code of Several Atari 7800 Games Released
jadoon88 writes to share a series of old Atari 7800 games that have been unofficially open sourced. "Remember Dig Dug or Centipede or Robotron? They used to be favorites when Atari's 7800 series was still around. Since the era of those consoles is over, and a different world of interactive reality gaming has taken over, Atari has unofficially released source code of over 15 games for the coders and enthusiasts to admire the state-of-the-art (because this is what it was back then). During those times, nobody would have imagined in their wildest dreams the games that Atari's developers floated into the gaming thirsty market and instantly swept across continental boundaries. But things changed soon after that and a company once regarded as one of the most successful gaming console manufacturers and developers faded away in the pages of our technology's hall-of-fame."
Should end in SPHINX.zip not Sphinx.zip. Beware the 404
Pain is merely failure leaving the body
You can be sure that the original arcade versions were written in assembly language not that different from what you see here. As a rule, nobody wrote video games in C until the mid 1980s. Assembly language was king.
I worked at a game software developer in the late 1980s, and all of the 2600 games, all of the 7800 games, all of the C-64 games, all of the Atari 800 games we developed or ported during the period were written in native assembly language. Only the Amiga, Atari ST, Macintosh, and the later PC games were written in C. NES and SuperNES games were written in assembly as well.
It's unofficial because it wasn't released by Atari, as the post suggests, but by the Atari Historical Society, copied from source disks recovered from Atari's trash.
Apparently Curt Vendel and Atarimuseum.com deserve the real credit for this release.
Looks like 6502.
Actually, it would have to be 65C02 or better. You couldn't do "ldx #$FF" on a 6502, you had to do "lda #$FF" and then "tax" (transfer A to X). The ability to load immediate into the X or Y registers was added on the 65C02. And, don't quote my on this, but I think the 7800 predated the 65816, so I suspect 65C02 is the right answer...
"Convictions are more dangerous enemies of truth than lies."
6502c, actually. It's a custom version of the 6502 that was integrated with various other system hardware and could dynamically adjust its clock depending on which memory address was being accessed. (That was how Atari gained 2600 compatibility, which was a custom 6507 chip.)
It sounded all well and good on paper, but the actual implementation of the processor was a serious PITA. If you weren't careful, you'd accidentally drop the speed to 1.19MHz and throw all your timings off. Even more annoying was that many functions required you to access hardware that dropped the clock speed. The worst offender was the TIA sound hardware because Atari was too cheap to install a POKEY chip.
Worse yet, the normal 1.79MHz was underpowered for the complex sprite hardware they'd paired it with. The sprite hardware basically processed lists of lists of sprites, requiring sophisiticated data structures to get good performance out of complex, fast moving scenes. And if that wasn't painful enough, you were wise to find a way to keep as much of the structure in ROM as possible so that you wouldn't blow through the mere 4K of RAM.
The 7800 was an interesting and potentially even useful design, but it simply wasn't practical for most developers. (Many of whom were not computer scientists.)
Javascript + Nintendo DSi = DSiCade
However, did they ever register the copyright for the source code? If not, then any damage awards for this "publication" won't amount to a hill of beans.
-1, Basic Copyright Knowledge Fail
Three smug ACs, all got it wrong.
If you do not register the copyright you can only sue for actual losses, none of this $150K per copy stuff that the MAFIAA gets away with.
Since this source code is assembly language for a decades old and long extinct game platform any actual losses due to publication and distribution of this source code won't amount to a hill of beans. The cost of the lawyer will probably dwarf any award, thus making it infeasible to file suit against the people who published it.
Capiche?
When information is power, privacy is freedom.