GroovyBee Posted November 2, 2010 Share Posted November 2, 2010 Just to be pedantic its not 2600 mode. Its a change in graphics colour depth resulting in the graphics data being used up twice as quick. 1 Quote Link to comment Share on other sites More sharing options...
toiletunes Posted January 29, 2011 Share Posted January 29, 2011 (edited) I also have the half-wide glitch. I haven't played much, but so far the glitch is on more than off. It's kind of a surprise when I suddenly see a nice helicopter or tank, etc for a fraction of a second- Then everything is smooshed again. Wonder what effect (if any) XM will have... Edited January 29, 2011 by toiletunes Quote Link to comment Share on other sites More sharing options...
toiletunes Posted July 9, 2011 Share Posted July 9, 2011 Okay, I finally got 2 copies of the game and 2 consoles- One console plays both games no problem (so far, further testing may be required) The other console has issues with one game, not the other. The glitchy game has 1987 copyright, the other game has 1988 copyright. SN for glitchy console A1 89 5484225 SN for other console 72R4BR A1 ?? (could be B something or 8 something, very faded/worn) 5261631 Hope this helps... Quote Link to comment Share on other sites More sharing options...
AtariLeaf Posted July 9, 2011 Author Share Posted July 9, 2011 Okay, I finally got 2 copies of the game and 2 consoles- One console plays both games no problem (so far, further testing may be required) The other console has issues with one game, not the other. The glitchy game has 1987 copyright, the other game has 1988 copyright. SN for glitchy console A1 89 5484225 SN for other console 72R4BR A1 ?? (could be B something or 8 something, very faded/worn) 5261631 Hope this helps... Interesting so perhaps a certain combination of 7800 motherboard revision and Choplifter cart version is causing these problems. Quote Link to comment Share on other sites More sharing options...
Atari Joe Posted July 9, 2011 Share Posted July 9, 2011 I hate to say they did a shit job of porting Choplifters! to the 7800. Have you seen it on the Sega Master System? It looks great. The 7800 was always capable of so much more than what was ever programmed for it the Jaguar too. 1 Quote Link to comment Share on other sites More sharing options...
toiletunes Posted July 9, 2011 Share Posted July 9, 2011 Just opened up the consoles: Rev A works fine Rev C has the glitch Quote Link to comment Share on other sites More sharing options...
toiletunes Posted July 12, 2011 Share Posted July 12, 2011 Last update- I got another copyright 1987 Choplifter, and it had the same glitch with the rev c 7800. Quote Link to comment Share on other sites More sharing options...
GroovyBee Posted July 12, 2011 Share Posted July 12, 2011 Is it possible to get a dump of the offending carts so that the differences can be compared? Quote Link to comment Share on other sites More sharing options...
+Mitch Posted July 12, 2011 Share Posted July 12, 2011 It wouldn't surprise me if it had more to do with the speed of the chip than the contents of the ROM. Though I'd still be happy to dump it if it was mailed to me. Mitch Quote Link to comment Share on other sites More sharing options...
toiletunes Posted July 12, 2011 Share Posted July 12, 2011 pm incoming Quote Link to comment Share on other sites More sharing options...
AtariLeaf Posted July 12, 2011 Author Share Posted July 12, 2011 Glad to see that it seems to be something other than defective hardware at play here. So it seems 1987 versions of choplifter don't play nice with Rev C 7800 motherboards, albeit a small sample size of course but still. . . Quote Link to comment Share on other sites More sharing options...
tz101 Posted July 12, 2011 Share Posted July 12, 2011 A little off topic, but still related: I bought Pac Man Collection from the AA store a couple months back. When it arrived, I tried it out and there were garbled characters all over the title screen, along with two horizontal black stripes that went through the mazes when I played. I cleaned my system contacts along with the cartridge pins, to no avail, and yet all my other 7800 and VCS games worked fine in this console. I contacted Al and sent the game back for a replacement. The replacement arrived, and the results were the same: Garbled characters on the title screen and black stripes through the playfield during game play. Al stated that he thought it was something with the "board" inside that batch of Pac Man Collection carts, and that he would send me one from a different batch of PCB's soon. The game arrived with the new board inside about a week ago, and it works flawlessly. What is different about my 7800 console? I don't know, but wonder if different "versions" of 7800 consoles could be causing the problems seen in the OP. Quote Link to comment Share on other sites More sharing options...
AtariLeaf Posted July 12, 2011 Author Share Posted July 12, 2011 I hate to say they did a shit job of porting Choplifters! to the 7800. Have you seen it on the Sega Master System? It looks great. The 7800 was always capable of so much more than what was ever programmed for it the Jaguar too. You're right Joe, same with Rampage. By far the best version is on the SMS IMO. Although I do like the 7800 Muppet Babies Rampage too Quote Link to comment Share on other sites More sharing options...
toiletunes Posted July 26, 2011 Share Posted July 26, 2011 I sent the carts to Mitch, here's what Mitch had to say: "I dumped them all and they all are an exact match for the existing dump. I took apart the one that had the hole over the screw and it had a resistor on the +5v line. So it's possible that there was a run of chips that had an issue and they had to use a resistor to drop the juice to the ROM chip. Maybe the incompatible consoles don't have clean enough power to make it work properly. But that's just a guess." The cart with the screw hole was 1987. When I got the carts back, I opened up the other two- Both 1987 carts had the resistor, the 1988 did not. Thank you Mitch for your help Quote Link to comment Share on other sites More sharing options...
gdement Posted July 26, 2011 Share Posted July 26, 2011 That's weird, I wonder how a resistor was supposed to be helpful. I've never heard of memory devices working better when you drop the voltage, only worse. Quote Link to comment Share on other sites More sharing options...
GroovyBee Posted July 26, 2011 Share Posted July 26, 2011 Any chance of an up close and in focus photo of the PCB around the resistor area? We might be able to work out what its connected to. Quote Link to comment Share on other sites More sharing options...
toiletunes Posted July 26, 2011 Share Posted July 26, 2011 pm incoming Quote Link to comment Share on other sites More sharing options...
GroovyBee Posted July 26, 2011 Share Posted July 26, 2011 From a chat with toiletunes it appears that the PCB is rev B (with resistor) on this page :- http://www.atarihq.com/danb/7800cart/C024926.shtml Schematic here :- http://www.atarihq.com/danb/7800cart/C024926.pdf The resistor is 150 ohms. Quote Link to comment Share on other sites More sharing options...
evietron Posted November 25, 2023 Share Posted November 25, 2023 (edited) On 10/25/2010 at 6:20 AM, GroovyBee said: The "half width" looks like the video mode has changed from 160A to 160B. Does this happen in the emulator? I don't play Choplifter much on my 7800. Writing junk to the Display List will cause a variety of problems including "half width" and the bars above. I can confirm this is caused by the display list RAM being corrupted due to contention with the joystick/6532 input. It's most likely a hardware bug with earlier revisions of the MARIA chip. Edited November 25, 2023 by evietron Quote Link to comment Share on other sites More sharing options...
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