Bruce Tomlin

Weight is the best way to be sure in many cases. Usually the chip in a 2600 cart was a mask ROM with a positive chip select. Standard EPROMs have a negative chip select, and need a 7404 inverter to work in a 2600. The weight of the extra chip (and the extra weight of a ceramic EPROM's case) would be rather difficult to hide. 2600 supercart games should also have a distinctive weight with two 24-pin chips on the board. On the other hand, many really rare games (and protos!) were made with an EPROM and a 7404, so you can't always be sure. And then there's the 7800 carts, where carts with a supercart board can be recycled easily for a repro. But 7800 supercart games used 28-pin mask ROMs, and because of the programming input, 128K-byte EPROMs are in 32-pin chips. So even 7800 repros can often be found out by their extra weight. One thing that could help is if a repro is put in a modern transparent case. But that doesn't stop someone from taking it apart and putting into in a salvaged Atari case. And of course, if the PCB is red, it's probably a repro. :-)

Mask-ROMs may die, just as any chip might, but they won't rot like EPROMs do. Even fuse-PROMs and fuse-PALs can suffer from rot, if the blown fuses start to re-crystallize just enough to conduct randomly.

On the subject of MMC cards, I noticed the other day when I was at Fry's, that they had a new endcap display for Palm. There were carded versions of memory cards, which while Palm branded, were apparently (due to the way things were worded on the package) all MMC cards. This even though all the Palm PDAs in that display were apparently capable of using SD cards. The interesting part is that there was a 256MB card for $99.

The impression I got when reading that a couple of months ago was that something was screwed up about the bank switch logic in the Dark Chambers 2600 cartridge. So they did something (which apparently already had been accounted for in the logic board design, but diked out in the first revision to be manufactured) which made that cartridge work, but Robot Tank and Decathlon would fail. These problems are apparently due to the electronics of the actual cartridge itself, which is why the Cuttle Cart 2 doesn't have special problems with these games. The rest of the problems are mostly due to the slightly different geometry of the cartridge port plastics. And then there are a couple (like Space Shuttle) which depended on the B&W switch being a switch and not a button.

Yep, it's 8-bit. Which has nothing to do with why the graphics are so primitive. That's because the TIA is a 1-dimensional graphics chip. Yep, 1D. It only remembers enough information for a single scan line. That's why a locked up 2600 will display a lot of vertical lines.

Where's my John Cougar [Melencamp] 2600 game?!?!?!!!! "Just a little ditty... about Jack and Dia-ane..."

Open it up and reseat the socketed chips. No need to remove them, just press them down firmly. This is especially important if you have an early model, because more chips were socketed in the early models.

Back in the day, 79 or 80, not sure which, was when we got our Atari. And we never called it the "VCS". So we must have just called it the "Atari".

Or... Atari 400, 800, 1200?

Wow, I remember when those were new. They were teh siht back in the day.

Well, the joystick ports could be used (I've used them for RS-232 myself), but it's kind of hard to play a game with a floppy drive plugged into the joystick ports. And you'd basically need another CPU (or lots of extra latches and decode logic) to control the floppy drive. It still can't beat the CC2. You can get any modern computer to write an MMC card with the proper USB adapter. Up to at least 256 megs each, not 256K. A 5 1/4" floppy drive is another matter, especially if you don't use a controller chip to read FM/MFM formatting. No way you're gonna get GCR unless you want to drag out an old Apple II to make the disks.

Argh. Now I see what you were doing. I just haven't found enough good docs on the 6532 yet. (Although I do have some 6530 docs, it's not quite close enough.)

INTIRQ (or any of the IRQ versions of the timer start registers) is completely useless on the 2600 or 7800, because the IRQ output from the 6532 is not connected to anything. (FWIW, only the 7800 even has the 6502 IRQ line connected, and that only comes from the cartridge slot.)

BZZZZZT! Not with the side port he ain't. Look at the schematics. That port basically only has video signals, and maybe a couple of CPU signals that aren't in the cartridge slot. The only way to get to the CPU bus without opening the case and soldering directly to the mother board is to make a pass-thru device (like the High Score Cart) that plugs into the cartridge slot.

Hmmmm... maybe I could use the difficulty switches as shift keys? Looks like I'll have to update my red box demo real soon now. (Even though I really want to get to work on my 7800 project.)

I wonder if someone could programme a blue box cart Oh, and put it in a blue cart too I already did, with my "red box" demo. It just needs the frequencies changed. I thought that regular DTMF was more important (since blue boxing tones are pretty useless these days), and with DTMF A, B, C, and D, there weren't enough keys left to put the 12 blue box tones anyhow.

Not that it's hard to find spare 7805 regulators if you have a good junkbox. Check the voltage coming out of it to make sure it's 5 volts. If it's outside of say 4.75 to 5.25, replace it. Especially since you said it looks crispy. Just for reference, the "M" in 78M05 means "medium power". An "L" means "low power", and 78L05 regulators are usually found in a transistor packaging. I don't know what the power ratings of M and L are, but a regular 7805 is 1 amp. 79xx regulators are for negative voltage regulation (for dual-polarity power supplies). And it's a power regulator, not a "reducer". It makes sure that the power coming out of it is exactly 5 volts (within some percentage range I don't know), and without any external parts, aside from filter capacitors. A 7805 needs 8-10 volts input to give good regulation. Definitely it needs to be on a heat sink for any reasonable power draw through it.

Depending on the game, you could add extra character tiles for scrolled parts of images. In the case of a bunch of right-angle roads with no "scenery", especially if you limit it to one direction, this should be possible. Mappy scrolling might be possible if you're careful, since it only scrolls horizontally, and mostly consists of horizontal and vertical lines for the background. Scrolling the sprites isn't (IIRC) a problem with CV.

The story, as I recall, was that one of the Vectrex developers had a bunch of 8" disks full of source code and a CP/M machine. The CP/M machine got stolen. http://groups.google.com/groups?selm=8scb5...0nnrp1.deja.com This is the only reference I was able to find, which implies that the disks may have been acquired by a collector with a less than friendly attitude.

I'm just glad to hear that the source got rescued. Somebody still needs to rescue all that Vectrex source code that's on 8" disks.

I thought the 2600 only used channels 3 and 4. Did you even TRY your TV on a channel other than 2?

Y'know, when you do open a Tigervision cart, you can go in there and flip the prong assembly around so the long side goes inside the cart. Then it works just fine with the 7800. But that's if you don't mind breaking the label to get at the screws. Anyhow, the first thing to do is try another console or three and see if it works better. Your cartridge slot may need cleaning too! I've taken apart those slot cleaning carts for NES, and cut them down to 2600 size. They're a piece of plastic with something like a very thick version of Scotch Magic Tape wrapped over the end. They really work, though you might have to clean the cleaner a few times for a really dirty console slot. The one tricky cart I had was a Bump n Jump. Some piece of plastic in the back had broken, so it couldn't be forced into the slot. I simply took it apart, stuffed a rolled up piece of receipt paper in the back of it, and it worked fine.

Yep, it seems to be missing a few things... like the boot ROM. I've always said the ROM was unnecessary for an emulator, but forcing the user to manually flip a switch is going a bit too far. It also seems to be lacking the INPTCTRL latch, in favor of the mode switch. It looks suspiciously leaner than the final design used in the 7800, so it must have been based on an earlier version of the 7800 design. The resolution of that picture is a bit too low to see everything that's going on.

You should also know that with one exception, the 2600 adapter is incompatible with the 4-port 5200. As far as I know, only one 4-port board revision was compatible without needing modifications. Did anyone ever find any info on what those modifications were?

Meteorites and Chase the Chuckwagon, a buck each or so (I think CtCW was bundled with a random cart for a total of $2) at the same thrift store, about two years apart. And the Atari Video Cube in a box of carts that a co-worker gave me for free. Next would be the find with Crazy Climber and Spy Hunter for $2 each that I had to wait for two weeks until they were put out for sale.