SkalTura

Yes, use the PLD/GAL file from PixelPast. If you play only 4k games (for 2k games, double them), you only need the CE signal from the PLD, so then it doesn't matter what file you use, since the A12, A13 and A14 lines (sideways jumpers F8, F6 and F4) will be jumpered to either +5v or GND, and not to the PLD anymore. And you don't have to use a 1M Eeprom, you can also use a 27C256 or 27C512 is you have hem. Just place it as marked on the silkscreen...

Cool ;-) Here are the Gerber files. Also made a short video on YouTube, so you can see it working. Note: Only tested with a few games (because my machine is PAL, and most of the games I downloaded are NTSC), but it seems to work fine for the ones I used for testing...

Did some further testing, and it seems to work fine for most ROM's. Even mixing up different sizes works for some ROM's. Let me know if someone is interested, then I will share the Gerber files for PCB making...

The PCB manufacturer sent me a new set of PCB's, and now it is working fine... :-)

Did some measuring, turns out that the PCB's are not correctly made. My design is correct, but for some reason the PCB manufacturer didn't make all traces going to the Eeprom ?

The unstable breadboard setup with many many many wires was working fine. Sometimes wiggling the wires was needed, but E.T (8k) started without much trouble. Once the wires were stable, I've restarted the Atari about 20 times and it always started E.T. So I designed the PCB for it, as shown in the previous post and had the PCB made. Received the PCB's a few days ago, and soldered one together for testing (don't mind the "F6", that was from a different test). But for some unknown reason it doesn't work at all, and I can't seem to figure out why. I've even tried it with the F8 PLD and 27C256 Eprom that were on the breadboard setup, but nothing. So I stuck the PLD and Eprom back on the breadboard, and it started first time... Super annoying !! Back to the drawing board ?

Designed a PCB that can be used for 2k/4k games, but also 8k, 16k and 32k games. Using the jumpers, you can select what type of bankswitching you want to use (F8/F6/F4, or no bankswitching). And with the rest of the jumpers, you can select different games. It uses a 1024k Eeprom (29F010 in my case), and a 20V8 PLD just like the PixelPast cartridge. So if you want to use 16k games for example, put jumper F8 and F6 sideways. The A12 and A13 signals from the PLD will then go to the Eeprom. The other jumpers can then be put to either up/down (+5V or Ground) for selecting 8 different games. If you want to use it for normal 4k games, use all jumpers to either +5V or Ground for selecting 32 games. Bankswitching is then not used, so the output of the PLD is only used for the Chip Enable signal. NOTE: Only tested with an (unstable) breadboard setup, so I will need to make the PCB to see if this is indeed a stable working solution... NOTE: Not sure if the PCB fits in all cartridge cases, but it does fit in the one I have. It think it was the case from Asteroids, but its been so long ago that I'm not sure of this.

Don't know if anyone ever thought of this, but just in case... Here are my findings... The PixelPast bankswitch card works as expected, using the F8 file for 8k games in the PLD, and a 27C256 Eprom. Since only A12 on the Eprom is used for bankswitching, A13 and A14 (as mentioned in the PLD file (thank you alex_79)) are only used to select where the game is started from. So I loaded 4 different 8k games in the Eprom and disconnected A13 and A14 from the PLD. Connecting A13 and A14 to either +5V or to ground, selects one of the 4 games. Games in the Eprom, in this order were: - Ms. Pacman - E.T. - Galaxian - StarGate Worked perfectly for Ms. Pacman and E.T. Galaxian started scrambled. SartGate didn't start at all. But to be honest, I tested this on a breadboard with about 50 wires connecting the PLD to the Eprom and the Atari connector, so a bit of instability was to be expected. I will make a PCB for it soon for more testing. And I guess it will also work for a F6 (16k) bankswitch card, selecting the games with only A14 (and A15 if you use a 27C512)

I have a UV box, so I don't mind erasing the chips. Usually keep the failed or old Eproms in a separate box, and erase then all at ones when I have 10 or so... I'm actually working on a cartridge that supports multiple F8 games, but wanted to try the PLD cart first to figure out if that was useful to me. So eventually I will indeed use a EEprom, maybe 4M or 8M so store several 8k games. Work in progress...

Yes, that did the trick... Many thanks !!

Ah, okay... I will try that. Thanks!

Anyone any experience with the bankswitch cartridge from PixelPast (http://www.grandideastudio.com/pixels-past/)...? Made one using the F8 program in the PLD, and Ms.Pacman (8k) but all I get is a black screen. There is no mention in the description of the card, but I wonder if I should fill the 27C256 with the same game multiple times ? Now I just programmed the 27C256 with 1 time Ms.Pacman, and filled the blank space with "FF", just like I would do on any other Eproms. Anyone ?

Other than the chip, it took me several minutes to get that stupid spring back in place ?

I recently had to open up my E.T cartridge because the plastic slider that protects the connector got stuck. To my surprise, there was only one chip (covered with a metal shield) on the board. I thought that E.T was an 8k game and therefore needs bankswitching...?

Okay, so basically not worth the effort... That's a shame, it's my favorite game to play on the Atari 2600. luckily I still have the original cartridge as well

Couldn't find much about it, so I'll ask the question here... If I understand it correctly, there is a custom chip in the original Pitfall II cartridge. But... would it be possible to make a Pitfall II cartridge with pure hardware (logic chips), so no PLD or other "software" based chips ? Thx!

I took out the Atari chip added a socket. Then I made the mod on a board with pins that go into the socket, and a socket for the Atari chip. In this way, you can always take out the mod and make the Atari original again... At first I didn't get sound, and there was no color. So I added a FMS6400 Dual Channel Video Drivers chip to the original schematic. Now everything is working perfectly. I have a small LCD TV in my workshop with an S-Video input. That gives me perfect picture. When I connect it to the LCD we have in the livingroom, using a S-Video to Scart converter, the picture is a bit blurry. I have 3 more of the FMS6400 chips. If you can't find it on eBay or in your local electronics shop, let me know...

Finally got it working... Look at the quality of the svideo signal, it almost perfect

Still the same problem... Perfect picture, but only black/white. I altered the circuit a bit and added the FMS6400 chip, like they use in the Longhorn mod. Now I do have color output, only there is a little bit of noise on the edges of the screen, but that doesn't bother me. Thanks!

Sound is working now... I had a faulty capacitor. But still no color though. Anyone ?

I will try that, thanks Jess... The sound problem is fixed by the way, turns out that the capacitor I put between the output and the connector to the TV was broken.

Question: I have a Darth Vader PAL Atari 2600, and made a A/V mod to it, but I don't have any sound, an the picture is in black/white. The picture is perfect however, only no color... Any idea what went wrong ?

I used a simylar circuit. The picture was perfect, but only in black/white, no color... and for some strange reason, also no sound eventhough the sound is directly connected to the Atari chip. (I have the Darth Vader PAL 2600)

Okay... I tried adding the pullup resistors, but now the screen is scrolling like crazy. My Atari 4 switch version is different from yours. Mine doesn't have the 4050 chip (see pictures). Could it be that the pullup resistors in your Atari are different from the ones that I need ? Also, even though I added the pullup resistor for the sound, I still don't hear anything.