cbmeeks Posted August 21, 2016 Share Posted August 21, 2016 Is it possible to read all Genesis controller buttons (A,B,C & Start) from an Atari 800? Without hardware modification or adapters? Thanks. Quote Link to comment Share on other sites More sharing options...
+Gemintronic Posted August 21, 2016 Share Posted August 21, 2016 Not an expert. Until one arrives.. I hear it's usually safe to read one of the genesis buttons at least on the 2600 and 7800. The problem is the way the genesis is wired compared to Atari systems. It usually sends wrong things. Quote Link to comment Share on other sites More sharing options...
gozar Posted August 22, 2016 Share Posted August 22, 2016 You can read the B button as the regular fire button and the C button (I think it's tied into the paddle inputs). Other than that, the A and the Start can't be read without hardware modifications. Sent from my iPhone using Tapatalk 1 Quote Link to comment Share on other sites More sharing options...
Rybags Posted August 22, 2016 Share Posted August 22, 2016 Pin 7 is normally NC on Atari sticks (+5V) unless used e.g. to drive an autofire circuit or other accessory item. On the Sega stick +5V is expected on pin 5 and pin 7 is used as Select to choose which buttons are returned. So, an unmodded controller won't allow all functions. I recall there being at least one Sega controller that was supposedly unsafe to use on Atari and C= machines, not sure which one though. Quote Link to comment Share on other sites More sharing options...
kenjennings Posted August 22, 2016 Share Posted August 22, 2016 I've tried several models, original sticks, and later models with more buttons, and third party remakes. None worked well with BASIC and stick() functions. After a few minutes the sega stick stops responding. Maybe there is some kind of polling protocol/PIA setup to write something top the port before reading the values. Quote Link to comment Share on other sites More sharing options...
Rybags Posted August 22, 2016 Share Posted August 22, 2016 The problem is we can only control output to pins 1-4 via PORTA/B. The STRIGs are read only. Amiga CD32 controllers I believe use output from the computer on this line for extra functions. The POTs are read only, connected from +5V/GND to the paddle pots. GND and +5V are fixed in their function. As I mentioned, from the pinouts guide, Sega chose to supply +5V on pin 5 and reassign Atari's +5V pin as a select line. Quote Link to comment Share on other sites More sharing options...
gozar Posted August 23, 2016 Share Posted August 23, 2016 I've tried several models, original sticks, and later models with more buttons, and third party remakes. None worked well with BASIC and stick() functions. After a few minutes the sega stick stops responding. Maybe there is some kind of polling protocol/PIA setup to write something top the port before reading the values. I've never had an issue with real Sega Genesis controllers, I use them in all of my Ataris. I do have a newer knock off controller that exhibits the same issue. But, it only happens in a machine with expanded memory. Quote Link to comment Share on other sites More sharing options...
Synthpopalooza Posted September 8, 2016 Share Posted September 8, 2016 Correct. I wrote a Tetris game in 1991 (Tetricize) that uses the B and C buttons on the Genesis controller for rotating blocks left and right. The controller can also be used on Bill Kendrick's "Gem Drop" and also possibly on the Atari 2600 Super Mario clone "Princess Rescue" (I can't remember if the programmer added this functionality or not). You can read the B button as the regular fire button and the C button (I think it's tied into the paddle inputs). Other than that, the A and the Start can't be read without hardware modifications.Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
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