+joeatari Posted March 23, 2019 Share Posted March 23, 2019 Is it okay to connect two different computers to your sio chain as long as you don't access your peripherals at the same time with both computers? For example a 130XE and 800XL using the same drives and printer? Quote Link to comment Share on other sites More sharing options...
Gunstar Posted March 24, 2019 Share Posted March 24, 2019 (edited) It should be fine as long as only one computer is on at a time. I think I did that about 15 years ago, actually. But I decided very soon that I wanted to be able to use both computers at the same time and so I added a switch to my APElink multi-SIO that switched between the two SIO ports that went to the two computers. I forget exactly how I rigged that, it worked fine, but I have long since removed it as I now have complete systems, as much as I need, and no need to share peripherals anymore. I was just thinking about something similar just yesterday though, but creating a switch box for the SIO just like those old VGA and RS232 switch boxes to connect up to 4 Atari's to the same SIO chain. Just a simple manual one. Edited March 24, 2019 by Gunstar Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted March 24, 2019 Share Posted March 24, 2019 (edited) No you must first diode protect the sio ports or add a switch between the them ! Depending on the Atari's involved you will back feed either 5 volts or 12 volts to the other computer. This browns out the first and kills the power supplies.. among other issue! Edited March 24, 2019 by _The Doctor__ 3 Quote Link to comment Share on other sites More sharing options...
Mathy Posted March 24, 2019 Share Posted March 24, 2019 Hello guys Try the automatic two computer interface. Sincerely Mathy 5 Quote Link to comment Share on other sites More sharing options...
Gunstar Posted March 24, 2019 Share Posted March 24, 2019 No you must first diode protect the sio ports or add a switch between the them ! Depending on the Atari's involved you will back feed either 5 volts or 12 volts to the other computer. This browns out the first and kills the power supplies.. among other issue! Thanks for catching error of my bad memory. That's probably what I figured out years ago which lead to the switch on APElink. I should have pondered more before replying. Quote Link to comment Share on other sites More sharing options...
+bob1200xl Posted March 24, 2019 Share Posted March 24, 2019 You should be able to connect two 1200XLs to a 1050, for example. Plug an SIO cable from each computer into one of the SIO connectors on the same 1050. You should be able to run either system from the I/O you have connected. In fact, all the I/O on both systems should share. The problem is with other computers that power the SIO interface. Each system may send +5v (or even +12v) into the SIO. The 1200XL (unmodified) has a 100 ohm limiting resistor on +5v, so it should be OK. Other systems may not be OK. Don't try this with tape drives like a 410 or 1010. They use MOTOR ON on SIO. You would have to look into that. Bob 3 Quote Link to comment Share on other sites More sharing options...
Gunstar Posted March 24, 2019 Share Posted March 24, 2019 (edited) You should be able to connect two 1200XLs to a 1050, for example. Plug an SIO cable from each computer into one of the SIO connectors on the same 1050. You should be able to run either system from the I/O you have connected. In fact, all the I/O on both systems should share. The problem is with other computers that power the SIO interface. Each system may send +5v (or even +12v) into the SIO. The 1200XL (unmodified) has a 100 ohm limiting resistor on +5v, so it should be OK. Other systems may not be OK. Don't try this with tape drives like a 410 or 1010. They use MOTOR ON on SIO. You would have to look into that. Bob That clears up my mystery and bad memory. That's why it worked for me, because I had 2 1200XL's at the time, though I do think I might have already added +5V fix to one of them...maybe not. I still had my 130XE at the time, but it was separate with it's own MyIDE HDD. Edited March 24, 2019 by Gunstar Quote Link to comment Share on other sites More sharing options...
+joeatari Posted March 24, 2019 Author Share Posted March 24, 2019 Thanks for all the great information. I'll ponder this and decide if I will build something 1 Quote Link to comment Share on other sites More sharing options...
+bob1200xl Posted March 24, 2019 Share Posted March 24, 2019 As long as one, not none, of the 1200XLs has the 100 ohm resistor in R63, it should be OK. Bob That clears up my mystery and bad memory. That's why it worked for me, because I had 2 1200XL's at the time, though I do think I might have already added +5V fix to one of them...maybe not. I still had my 130XE at the time, but it was separate with it's own MyIDE HDD. 1 Quote Link to comment Share on other sites More sharing options...
Guest Posted March 31, 2019 Share Posted March 31, 2019 (edited) quintopus deluxe will do two computers/multiple devices (two-switches). Edited March 31, 2019 by Guest Quote Link to comment Share on other sites More sharing options...
jcbstein Posted April 1, 2019 Share Posted April 1, 2019 This is how I do what your asking about. 1 Quote Link to comment Share on other sites More sharing options...
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.