VCS POP kiosk ROM dumping (was Spiked Asteroids?)

[djpubba]

I recently purchased the guts of an Atari 2600 VCS POP kiosk from eBay seller SafeStuff.com (the guy with all the Atari arcade protos).

 

It's the motherboard from this thing:

 

http://www.atarimuseum.com/videogames/cons...00displays.html

 

There are signs that this particular PCB was never used "in the wild." The interface buttons are on the end of a hand made harness with small push buttons mounted to the kind of perf board I've seen used in other Atari protos. It came populated with 46 game ROMs. It has slots for 47 ROMs but slot 7 was empty. Looking at the docs I found on the internet for the kiosk, it seems that technicians were supposed to remove the ROM in slot 7 in order to use the cartridge slot to do diagnostics. The docs say that slot 7 was Breakout.

 

The really interesting thing is that the docs show that the original was populated with only 42 games. I have 6 games which differ from what the docs say should be there. They are labeled "Weird Air-Sea Battle," "Spiked Asteroids" two Berzerks, Defender and Warlords.

 

Weird Air-Sea Battle looks just like Demons to Diamonds. Spiked Asteroids doesn't play. When you start it, it sits on the copyright screen and a few of the letters cycle. The copyright looks just like the copyright from the version of Asteroids with a copyright. The Berzerks don't boot at all and Defender looks and plays just like the normal Defender. Warlords looks and plays like the normal Warlords.

 

I have an EPROM programmer and would like to dump these to compare to retail carts to see if they're unreleased. However, when I try to read them as 2732's, they come out blank. They're not blank because they play in the PCB. I did a little research about Atari 2600 masked ROMs and the info I found says that pin 18 is pulled high instead of low as a normal 2732. I tried pulling pin 18 out of the socket and jumpering it to the VCC pin but it still comes out blank.

 

Anyone know the pinouts for Atari 2600 masked ROMs or have any tips about how to dump these?

 

Oh, here's a picture:

 

http://www.hardcoregamer.com/images/blogs/...a/ataripos4.jpg

Edited July 23, 2007 by djpubba

[+Mitch]

They're actually 2532 pin compatible not 2732.

 

Mitch

[djpubba]

Well, they're close to 2532's. It turns out they're actually 2332 masked ROMs. They have two chip selects on pins 20 and 21 which need to be pulled high. I successfully dumped "Weird Air-Sea Battle" and it's identical to Demons to Diamonds. I have not been able to dump "Spiked Asteroids" (or regular Asteroids). I suspect it's because they're 8k ROMs. This probably means Spiked Asteroids is just going to be the regular copyright version of Asteroids. Still, it'd be nice to confirm. I need to figure out what their pinouts are and see which EPROMs my reader supports that are the closest match. I suspect they're compatible with the TMS4764, maybe?

 

I dumped the front end 2716 though. It runs under emulator just fine.

Edited July 23, 2007 by djpubba

[Bruce Tomlin]

You can't dump an 8K game with an EPROM reader because they don't know how to do the bank select.

 

If they are bare chips, make a socket cart by desoldering the chip from a Pac-Man and replacing it with a socket. (either ZIF or regular, but avoid the round-pin sockets because they can be too finicky about bent pins)

 

Then use hacked 7800 with DevOS to dump the games.

Edited July 23, 2007 by Bruce Tomlin

[PacManPlus]

... I don't suppose you could post the front end, could you?

 

 

Also, wasn't there someone on this board who was making reproductions of those kiosks? (and very good ones at that) - whatever happened to him?

[djpubba]

If they are bare chips, make a socket cart by desoldering the chip from a Pac-Man and replacing it with a socket. (either ZIF or regular, but avoid the round-pin sockets because they can be too finicky about bent pins)

 

Then use hacked 7800 with DevOS to dump the games.

 

This sounds like a lot of work. I can't swap banks by manually pulling the high address line low on the first dump and high on the second? That'd be easier.

 

Sure, I'll post the front end. But my wife is having a baby and I'm really tired lately and I have a lot of bills and I just wrote a book I need to promote, so I'll get that posted real soon now, but I can't say when. Just kidding. Attached.

 

You can't change the game select number under emulation because the bits on that port aren't mapped to any keys in any emulators.

VCSPOP.zip

[CPUWIZ]

I can't swap banks by manually pulling the high address line low on the first dump and high on the second? That'd be easier.

 

No, because bankswitching on those chips is done via touching a "hot-spot" in memory, in the case of 8K it would be $1ff8 and $1ff9.

[djpubba]

Wouldn't that kind of bank switching be handled by custom logic inside the cart, external to the ROM? So the ROM would be a "normal" 8K ROM? Just guessing here, but I'd be a little surprised if Atari made custom ROMs with the bank switching logic built into the chip. Did they?!

 

Edit: oh, hey, post #6 in this thread shows a pinout for an adapter to use a 2764 in place of an 8k Atari masked ROM from an 800Xl.

 

http://www.atariage.com/forums/index.php?showtopic=110394

 

I think I'll try that.

Edited July 23, 2007 by djpubba

[djpubba]

Edit: oh, hey, post #6 in this thread shows a pinout for an adapter to use a 2764 in place of an 8k Atari masked ROM from an 800Xl.

 

http://www.atariage.com/forums/index.php?showtopic=110394

 

I think I'll try that.

 

No luck These chips must have bank switching logic inside. Yuk.

 

Are the part numbers on the chips unique to each game? Is C016449B-06 Rev B. of Asteroids?

[PacManPlus]

Thank you for attaching it. I'm curious to disassemble it and see what it does

[PacManPlus]

Edit: oh, hey, post #6 in this thread shows a pinout for an adapter to use a 2764 in place of an 8k Atari masked ROM from an 800Xl.

 

http://www.atariage.com/forums/index.php?showtopic=110394

 

I think I'll try that.

 

No luck These chips must have bank switching logic inside. Yuk.

 

Are the part numbers on the chips unique to each game? Is C016449B-06 Rev B. of Asteroids?

 

 

I think they do.

 

Hey, just a thought, guys - can't he use the same program that was used to dump the FB2? The program that was 128 bytes long and loaded in RAM?

 

http://www.atariage.com/forums/index.php?s...mp;hl=Dump+ROMS

Edited July 24, 2007 by PacManPlus

[Bruce Tomlin]

Wouldn't that kind of bank switching be handled by custom logic inside the cart, external to the ROM? So the ROM would be a "normal" 8K ROM? Just guessing here, but I'd be a little surprised if Atari made custom ROMs with the bank switching logic built into the chip. Did they?!

Why do you think they couldn't? This is the same Atari that would over-order ROM chips just to keep the fabs busy and unable to run orders for their competitors.

[djpubba]

I didn't think they couldn't, I just didn't think they would from a cost standpoint, but I didn't consider the anti-piracy value.

[Bruce Tomlin]

It has nothing to do with piracy, and everything to do with cost. Since the chip is only addressed in a 4K window anyhow, it doesn't need the pinout of a chip larger than 4K, and Atari could keep using the same boards that they had a bajillion of already.

 

They pay a few tens of thousands of dollars once to get a new mask made with a bit of bank select logic on it (basically a big AND gate and a latch), and they can re-use it forever at no extra cost, on the same circuit boards they've always had.

[djpubba]

Having a custom chip made is definitely going to cost more than using off the shelf parts. It's extremely rare for a game manufacturer to do this for a ROM chip. This is the first example I've run across in the 20 years I've been tinkering with arcade game boards and their ROMs.

 

Plus, there are plenty of off-the-shelf 8k PROMs with only 24 pins — 2364, 68764, 7144, 82S641, 76641, 27S49, 93Z565..., so I'm not convinced by your pinout suggestion either.

 

I could be totally wrong, of course. Just going by my gut.

Edited July 25, 2007 by djpubba

[PacManPlus]

So I guess what I suggested above isn't worth trying It did say in the link that it would work for regular 2600s...

[djpubba]

If I thought there was a good chance of it being unreleased any more, I'd look into your suggestion further, but I'm fairly convinced that it's going to be the retail release of Asteroids. Therefore I've put a lower priority on getting it dumped.

[Bruce Tomlin]

Having a custom chip made is definitely going to cost more than using off the shelf parts. It's extremely rare for a game manufacturer to do this for a ROM chip. This is the first example I've run across in the 20 years I've been tinkering with arcade game boards and their ROMs.

That would be because these aren't arcade ROMs. A whole different economy applies to console games. Console ROMs are manufactured in the millions, not the thousands. The extra cost of a standard chip with a few gates added on the side approaches zero as you produce an infinite number of chips. In fact, it even goes negative if you count not having to redesign the cartridge boards or having to include the equivalent TTL chips.

 

Not only that, but once it was done, anybody could order that special type of ROM, whether Atari liked it or not. Even Bounty Bob Strikes Back for the 5200 used two 8K 2600 chips to get some extra space!

 

And Atari's wasn't the only instance. Parker Brothers had their own more flexible 8K bank switching method which was built into their chips.

 

Anyhow, the point is that EPROM readers aren't made to do non-sequential reading of chip addresses. You can't tell them to read $01F8 or $01F9 before every data read. (at least not unless you have an open-source programmer, and the chip companies don't much like having their programming algorithms in open software)

 

EDIT: look up the 27011 and 27513. These were EPROM parts made by Intel which supported bank switching by writing the bank number on the data lines! (similar to the 7800-style bank switching) One place that I worked at started with 27128 parts, then went with these to get more space in the same socket. This cursed them to need bank select adapter boards (that took a 28F010) for a long time, especially when the '011 and '513 were discontinued.

Edited July 26, 2007 by Bruce Tomlin

[djpubba]

Okay, well, I'll buy that. Anyway, my experience being with arcade ROMs only is why I was surprised they did what they did.

[djpubba]

Here's how I hooked it up, fwiw.

 

http://www.hardcoregamer.com/index.php?opt...g11603#msg11603

[JL]

Here's how I hooked it up, fwiw.

 

http://www.hardcoregamer.com/index.php?opt...g11603#msg11603

 

Really, really cool!

[PacManPlus]

Yes, Very nice

 

I actually had an Intellivision one like that back in the day. The games were timed (that is, until I removed the chip that the timer runs on!)

 

... Wish I still had it now

[A.J. Franzman]

Here's how I hooked it up, fwiw.

 

http://www.hardcoregamer.com/index.php?opt...g11603#msg11603

Since the unit has several paddle games installed, I would assume that it works fine with paddle controllers and yours just need cleaning (or are worn out).

[supercat]

Having a custom chip made is definitely going to cost more than using off the shelf parts. It's extremely rare for a game manufacturer to do this for a ROM chip. This is the first example I've run across in the 20 years I've been tinkering with arcade game boards and their ROMs.

 

Interfacing a 2764 to an Atari 2600 would have required a custom logic chip, a PLD, or else at least two, if not three, standard logic chips--at least until 2006 anyway(*). The one-time extra cost of engineering the bank-select circuitry in a cartridge ROM get recouped pretty quickly by the savings in other logic.

 

(*) The single-chip technique that was invented in 2006 would have worked just as well in 1977, had someone invented it then, but nobody did.

Edited July 27, 2007 by supercat

[+batari]

Having a custom chip made is definitely going to cost more than using off the shelf parts. It's extremely rare for a game manufacturer to do this for a ROM chip. This is the first example I've run across in the 20 years I've been tinkering with arcade game boards and their ROMs.

 

Interfacing a 2764 to an Atari 2600 would have required a custom logic chip, a PLD, or else at least two, if not three, standard logic chips--at least until 2006 anyway(*). The one-time extra cost of engineering the bank-select circuitry in a cartridge ROM get recouped pretty quickly by the savings in other logic.

 

(*) The single-chip technique that was invented in 2006 would have worked just as well in 1977, had someone invented it then, but nobody did.

Tigervision 3F can be done with a single chip.