SIO issues: Cannot use peripherals

[_The Doctor__]

The 520 supply only needs the 5 volt and ground attached to the wire your snagging off the ingot...

The 12 volt section has been used as an injector for the 12 v pin on SIO cord to devices that required it on the later machines that did not supply it... but that's not needed...

[Kyle22]

20 hours ago, Porkchops & Applesauce said:

@Nezgar  Thanks for confirming.  All are 31VA.  I believe the one in the middle came with the 1010 drive (bought new), and the other two with the 810's (used).  Cheers friend!

Stop! Don't cut that open just yet. Check under the rubber feet for screws. Some of them come apart nicely.

I'm looking at the one on the left that still has all four feet attached.

 

[_The Doctor__]

the block in the center has screws under the rubber plugs the other 2 do not

[Kyle22]

1 hour ago, _The Doctor__ said:

the block in the center has screws under the rubber plugs the other 2 do not

After I put my glasses on, I see the middle one does have its feet. Without my glasses, the glare made it look as if the middle one had sticky glue dots.

 

It's always good to check before cutting anything open.

 

[Porkchops & Applesauce]

@_The Doctor__ Can confirm the Japan model uses screws, while the Taiwan ones don't.

 

 @Kyle22 Good point. Best to check first if the power adapter uses screws before ripping into it.

 

Cheers friends!

[Porkchops & Applesauce]

Greetings friends,

 

I'm happy to report that my Atari 800XL is working again!  It's now communicating with the peripherals, and I can confirm after replacing the POKEY chip that it was the problem.  I want to thank all of you for the support and awesome advice - thank you kindly!

 

Now that everything is talking to each other again I'm finding new issues and may need to start new threads for help. I'm hoping after 20+ years of storage that perhaps these issues can be resolved with some general cleaning and maintenance.  We'll see.  Right now my priority is to replace my "Ingot" power supply before I lose what I've gained.  Thanks again for the tip guys!  As mentioned, I have a 520ST power supply with matching XL style I plan to re-purpose.  I've chosen to replace the ST connector (disabling +12V of course) rather than reuse the cord+connector from the existing XL power supply.

 

Before wrapping it up, I though it might be helpful to summarize the issue I was having and steps to diagnose the bad POKEY chip for anyone who may stumble across this thread in the future:

 

- Atari 800XL boots to READY prompt but unable to use peripherals (Two 810 drives, 1010 tape drive, and 1025 printer).  Computer passes all self tests.

 

- No response from either 810 drive when booting computer. Tried in pair and individually configured as D1.  With computer off, both drives power lights come on, and busy lights momentarily on while hearing hub motor spin and stepper motor reset.

 

- 1010 tape drive motor would respond to CLOAD/CSAVE commands, but confirmed using external audio tape player that drive would not record audio, or load previously recorded tapes - Error 138.

 

- 1025 printer head would reset upon turning on computer.  Would not respond to LPRINT command - Error 138.

 

- Confirmed +5V power to computer.

 

- Confirmed continuity from end of SIO cable to soldered socket pins on computer motherboard.
 

- Removed all socket chips from the motherboard and cleaned everything before re-installing.

 

It's probably worth noting that I also tried a new PIA chip ($1.95 USD) before replacing the POKEY ($20 USD), both purchased at the same time from Best Electronics.

 

Cheers friends!

 

[xrbrevin]

success!

atari hardware doesnt die, it just needs some tenacity and TLC for resurrection!

[+DrVenkman]

5 hours ago, Porkchops & Applesauce said:

- 1010 tape drive motor would respond to CLOAD/CSAVE commands, but confirmed using external audio tape player that drive would not record audio, or load previously recorded tapes - Error 138

That really should have been a big clue: the 6520’s role in serial I/O is limited to cassette PROCEED, MTR-CTRL, INTRUPT and COMMAND but that actual DATA IN and DATA OUT are handled by POKEY. So that’s why your program recorder would start and stop, but not record any data.

 

Anyway, congrats on getting your machine back up and running, and good luck with the new PSU.

[Sinjinhawke]

2 hours ago, DrVenkman said:

That really should have been a big clue: the 6520’s role in serial I/O is limited to cassette PROCEED, MTR-CTRL, INTRUPT and COMMAND but that actual DATA IN and DATA OUT are handled by POKEY. So that’s why your program recorder would start and stop, but not record any data.

This thread has been very informative.  I have a 600xl that has this exact behaviour.  Even an SDrive plugged into the SIO is not seen.   While I have moved on to a 130XE I think I’ll order a POKEY chip to see if it helps.  Makes me sad seeing my childhood computer sitting in a box.  

[+Nezgar]

10 hours ago, Porkchops & Applesauce said:

I'm happy to report that my Atari 800XL is working again!  It's now communicating with the peripherals, and I can confirm after replacing the POKEY chip that it was the problem.  I want to thank all of you for the support and awesome advice - thank you kindly!

Excellent, good to hear success stories. Just wanted to add that since the audio portion of that POKEY still seems OK, don't throw it out as it can probably still be used as the 2nd POKEY if you ever upgrade this or another machine to a dual POKEY/stereo setup. Only the audio functions are needed for the 2nd POKEY.

 

Cheers!

[Porkchops & Applesauce]

16 hours ago, DrVenkman said:

That really should have been a big clue: the 6520’s role in serial I/O is limited to cassette PROCEED, MTR-CTRL, INTRUPT and COMMAND but that actual DATA IN and DATA OUT are handled by POKEY. So that’s why your program recorder would start and stop, but not record any data.

Thanks, I'm sure this will be very helpful to others having similar issues.  I forgot to add in my summary that I was also able to load a cartridge and use my joystick.  If I'm not mistaken I believe this is further evidence the PIA was okay?

[Porkchops & Applesauce]

11 hours ago, Nezgar said:

dual POKEY/stereo setup

Thanks for the tip.  Cheers friend!

[Porkchops & Applesauce]

14 hours ago, Sinjinhawke said:

I think I’ll order a POKEY chip to see if it helps.  Makes me sad seeing my childhood computer sitting in a box.

I wish you much luck my friend.  I know that feeling well.  This has been my computer since childhood.

[+DrVenkman]

7 hours ago, Porkchops & Applesauce said:

Thanks, I'm sure this will be very helpful to others having similar issues.  I forgot to add in my summary that I was also able to load a cartridge and use my joystick.  If I'm not mistaken I believe this is further evidence the PIA was okay?

Possibly but with a caveat - as your initial symptoms indicated, you had sound from POKEY despite the lack of serial I/O function. So the chip was partially functional. I have never run into a bad PIA on any of my computers (*), but I have had a POKEY with the same symptoms of yours; I’ve had partially-working 6532 RIOT chips in 2600s (one or the the other difficulty switches not working but everything else fine); I’ve had partially working TIA chips in 2600s (colors incorrect or graphics slightly distorted but sound working fine); and I’ve had glitchy GITA ships in A8s where the graphics get distorted when the chip heats up, but on a cold boot when the machine had been off for 30 minutes or so, it would work fine for about 10 minutes.

 

So I think that it was a good clue that your PIA was fine, but the fact that the joysticks work didn’t necessarily mean the *entire* chip worked fine. Does that make sense?

 

(*) I’ve had a bad socket that made it appear that the PIA was bad. Turns out that several of the socket wipes - the metal bands inside the socket that contact the pins and then extend down into the PCB to be soldered - were corroded badly and not making good contact. I replaced that socket and the original chip worked fine. I think the possibility that sockets are bad or marginal on these computers after several decades is something that really should be taken into account by more folks. Atari typically used cheap single-wipe sockets and they lose spring tension, get corroded and in some cases they actually break - that happened on a difference socket on the same machine I mentioned above.