flip

Thanks - I've put the list + other roms I know of into a Google Sheet The top row would be one of the hex encoders, the left column the other. As it stands, 47 slots would be filled (some with duplicates). Using an 8Mbit EPROM, 209 slot remain empty, which is a lot. So a 4Mbit EPROM would be enough (leaving 81 slots free). One caveat: I've tried contacting Lee Romanow to ask his permission to include his ROMs, but haven't heard back. I'm not looking to make this a commercial product but his license is nevertheless restrictive (e.g. distribution is only allowed in ST2 format). Not sure he's on this forum or if anyone is in touch with him but if you are, I would be grateful if he could get in touch. flip

If I use an 8Mbit EPROM (27c801 or 27c080), I have 256 slots. Using 2 hex encoders, as BigO suggested, would enable those to be selected. Having so many slots could enable some sort of organisation: 0x00-0x1f (32 slots) would be RCA originals; 0x20-0x2F (16 slots) would be Paul Robson's games, etc. Does that make sense? I guess it would even hold the games for other, compatible systems as well... Is there a definitive list of official & homebrew games somewhere that I can copy and paste from? flip

The initial version is designed for 16 titles - for simplicity, it uses a rotary hex switch with 16 positions (0->F) to select the game you want to play. I might try and expand that in a second version, but I'd like to get this one up and running first... PCBs are ordered. I'll post an update when I get them... flip

Hi all, Haven't posted in this thread before, but incredible work being done in this group! I've decided to have a go at building a S2 multicart, based on the info on Paul Robson's page Using a 2764 EPROM that holds two games, the protype is working. It also confirms that Paul's design is correct (as if that was in any doubt)! Next step is to design a PCB to hold a 27c512 that has 16 game-roms, using a hex decoder switch to select the games. flip

Hi, Found this topic just now, so apologies for bumping such an old issue. Did you ever manage to solve the issue of missing pixels? I had the same on my box and it is definitely related to the RAM chips. I found them on ebay, replaced them - all the pixels are available again. In fact, finding the sockets for the RAM chips was the hardest part, as they are wider than normal ICs... regards, flip

Excellent points - especially the one about the game continuing. I hadn't considered that - there doesn't appear to be a loopback that halts the logic if the beam is cut... I guess the same goes for the timer issues. Problem with the tests is that I can't get past the title screen of the test cart. The first test (listed as #3 in the service manual) fails and I can't get to the next ones... I had replaced a number of chips on the logic board hoping to resolve the issue, including the ROM. That's an EPROM, which tests fine in my programmer. The two ram chips were also replaced with new ones, though I realise that that doesn't rule out they could be faulty... Looks like I'll have to go back to the logic board to see whether anything weird is going on there, possibly in the DAC part... Philip

Thanks for the reply. It's reproducible. When test #3 (linearity test) comes up, the screen goes blank. Oddly enough, some games play fine (Minestorm for example), while Berserk for example seems to experience the same problem. Pressing a button doesn't recover - only switching off or reset does. The main voltages (-5, 5 and -13v) remain stable when the screen goes blank. I'm looking at the 555 and the two potentiometers (R525 and R526) there, but they are hard to reach... I'm pretty sure the problem is on the 'power' board rather than on the logic side... Thanks for thinking along, Philip

Hi, I've been trying to fix a buzz-model Vectrex with an odd problem: with certain games, the beam seems to turn off. Annoyingly, the first test pattern on the test cart also does this. Other games runs perfectly normal. I've recapped the machine, but that hasn't solved the issue. I am guessing the problem is in the Deflection Detection/Beam Limit circuit but before starting to swap random components, I'm wondering whether anyone has come across this - and how they've solved it? Cheers, Philip

Long time fan of Chip's Challenge, so I'd love to get a code as well - I've sent a friend request on steam (pmarien) Cheers, flip

Hi, Just wanted to use my first post to praise the screens: I installed one on my Lynx II today, and it's more than worth it. The instructions that come with it are clear and to the point. If you're comfortable with a soldering iron, it installs in about an hour and the difference is to die for. Hopefully, the same will become possible for model I ! flip