Ed Fries Posted May 26, 2016 Share Posted May 26, 2016 What was the first color arcade video game? I say it was Color Gotcha: https://edfries.wordpress.com/2016/05/25/fixing-color-gotcha/ 12 Quote Link to comment Share on other sites More sharing options...
Albert Posted May 26, 2016 Share Posted May 26, 2016 I read this in its entirety earlier today. So fantastic, I'm glad you persevered! Thank you for sharing your experience! ..Al 1 Quote Link to comment Share on other sites More sharing options...
iesposta Posted May 27, 2016 Share Posted May 27, 2016 I read the entire Wordpress also. Extremely fascinating and enjoyable, thanks! Even Nolan Bushnell was not sure, wow! My "guess" would have been 6 years later! (Probably most people saw Galaxian when it came as a color screen and not black and white with a color overlay.) I was 12 in 1979 and I am still finding games from 1984 back that I never saw or played! 1 Quote Link to comment Share on other sites More sharing options...
BigO Posted May 27, 2016 Share Posted May 27, 2016 Thanks for the interesting write up and the motivation to carry on with my own repair project of a somewhat obscure (ca. '76, but historically meaningless) machine. 1 Quote Link to comment Share on other sites More sharing options...
+nanochess Posted May 27, 2016 Share Posted May 27, 2016 Great article! 1 Quote Link to comment Share on other sites More sharing options...
BurritoBeans Posted May 27, 2016 Share Posted May 27, 2016 Wow, sweet article you wrote up! I would've never guessed that Color Gotcha was a thing - I never even heard much about Gotcha in the first place so it wouldn't have been a guess I'd ever make. I love reading these repair projects, and that sure looks like a heck of a project - thanks for posting that article on here. 1 Quote Link to comment Share on other sites More sharing options...
Bryan Posted May 27, 2016 Share Posted May 27, 2016 Thanks! I just read it too. I love this stuff!! By the way, an Open Collector (or Open Drain in FET terms) output is one that's missing the pull-up transistor. Normally, logic chips have a transistor to clamp the output to ground and another one to clamp it to the Vdd rail. By eliminating the 2nd one, the output simply becomes disconnected (or floats) when the output is "high". This can be handy in several instances, but the primary one is the wired-AND configuration. Normally, outputs cannot be combined but you can put many open collector outputs on a single trace with a pull-up resistor (of several Kohms or so, depending on your rise-time requirements) and that signal will be high as long as none of the outputs are low (clamped to ground). This eliminates the need for additional ICs with enough inputs to compare all those output pins. 1 Quote Link to comment Share on other sites More sharing options...
+SpiceWare Posted May 27, 2016 Share Posted May 27, 2016 Awesome! Your bit about the counters and X and Y locations is somewhat true for the 2600 as well. If you check the disassembly for Combat you'll see RAM allocated for TankY0, TankY1, MissileY0 and MissileY1 but nothing for the X location. Instead, it uses RESPx to set the initial positions of the tanks at the start of each match, then uses HMOVE to adjust their X locations over successive frames. 1 Quote Link to comment Share on other sites More sharing options...
Ed Fries Posted May 27, 2016 Author Share Posted May 27, 2016 Awesome! Your bit about the counters and X and Y locations is somewhat true for the 2600 as well. If you check the disassembly for Combat you'll see RAM allocated for TankY0, TankY1, MissileY0 and MissileY1 but nothing for the X location. Instead, it uses RESPx to set the initial positions of the tanks at the start of each match, then uses HMOVE to adjust their X locations over successive frames. Yeah, I think you are exactly right. The crazy RESPx, HMxx stuff must be a direct descendant of the slipping counter way of thinking about things. Quote Link to comment Share on other sites More sharing options...
Retro Rogue Posted May 27, 2016 Share Posted May 27, 2016 Yeah, I think you are exactly right. The crazy RESPx, HMxx stuff must be a direct descendant of the slipping counter way of thinking about things. Yup, it was designed similar to how Cyan was already doing that stuff in coin (Cyan was doing most of the protos and proof of concepts for coin and then they'd be sent down to Atari to be put in production format). Not a huge leap from how things were already being done then when creating versions of all those earl and mid 70s coins for it then. Quote Link to comment Share on other sites More sharing options...
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