SIO issues: Cannot use peripherals

[Porkchops & Applesauce]

So I pulled my 800XL and gear from storage.  It'll boot up to READY prompt, play a cartridge game, and pass all self tests.  However, I'm unable to use any of my peripherals (2x 810 drives - one Happy, 1010 recorder, and 1025 printer).  Any help isolating the problem is greatly appreciated.

 

Here's what I've tried so far...

 

- CSAVE: No apparent issues trying to save "hello world" program to cassette. Beeps and starts spinning while recording.  Back to READY prompt and recorder stops when done.

 

- CLOAD: Error 138. Apparently didn't record. RETURN key properly starts recorder playing but no noises.

 

- LIST/LOAD D1 & D2: Error 130. Nothing. Neither drive will spin when turning computer on. OPTION-on goes straight to test screen. Drive switches are set to 1 & 2, and have tried swapping them, plus each individually as D1.  Note: Drives will power up with momentary busy light when computer is off.

 

- LIST "P:": Error 138. Nothing. Printer head resets position when turning on computer.

 

I've tried all peripherals daisy chained and individually, swapping out the IO cables with same results.  I removed all socket chips from the motherboard, cleaned everything and no difference.

 

Need a new POKEY chip?  Anything else it could be?  Thanks for the help guys!

 

[Urchlay]

Might just need to clean the SIO cables & port. Get a can of Deoxit
or QD electronics cleaner, spray into all the holes in the ends of all
your SIO cables. After spraying each one plug/unplug it in the SIO port
a few times.

If that doesn't help, try replacing the SIO cables, if you can find any
on ebay or whatever.

The tape you tried to CSAVE to, what happens if you listen to it on a
regular audio tape player? You should hear the squeals and jangly data
blocks, if it actually recorded anything.

It's possible you have a bad POKEY, but the machine boots and you
can hear audio during the audio/visual part of the self-test, and the
keyboard works, right? So the POKEY is at least somewhat working. A
replacement is pretty easy to get, worth a try, if cleaning the cables &
port doesn't help.

[xrbrevin]

bent pin in the socket?

[Porkchops & Applesauce]

1 hour ago, Urchlay said:

Might just need to clean the SIO cables & port. Get a can of Deoxit
or QD electronics cleaner, spray into all the holes in the ends of all
your SIO cables. After spraying each one plug/unplug it in the SIO port
a few times.

If that doesn't help, try replacing the SIO cables, if you can find any
on ebay or whatever.

The tape you tried to CSAVE to, what happens if you listen to it on a
regular audio tape player? You should hear the squeals and jangly data
blocks, if it actually recorded anything.

It's possible you have a bad POKEY, but the machine boots and you
can hear audio during the audio/visual part of the self-test, and the
keyboard works, right? So the POKEY is at least somewhat working. A
replacement is pretty easy to get, worth a try, if cleaning the cables &
port doesn't help.

Thanks for the tips.  Yes, all keys work.  All cables and ports have been cleaned using contact cleaner. Tried all four SIO cables (one of them the good brand with round sockets) in both 1010 ports.  Always Error 140.  I've verified nothing was recorded for my test program using an audio tape player. 

 

I want to add that when I try to load a prerecorded commercial program tape I don't hear that high-pitch lead-in that I seem to recall I should through the TV speaker.  My audio tape player however confirms it's there.  I do hear some "squeals" momentarily before the Error 140 appears, but it doesn't sound like the ones on the tape.  It's a much lower tone.  I hear the same thing using my test tape that I've confirmed has nothing on it.  Also, I did notice if I boot using power-START I'll get a BOOT ERROR message and the tape will continue running (still no sound from the cassette).  I only get the Error 140 using CLOAD.

 

At 1/4 to 1/3 the cost of a new 800XL I'm hesitant to replace the POKEY chip without reasonable certainty that's the cause.  As you mentioned, it does appear to be somewhat working (e.g. passing sound tests & starting/stopping the tape player).  I'd love to know if there's a way to confirm it's the POKEY chip using nothing more than what I've got and perhaps a multimeter.

 

Cheers friend!

[Porkchops & Applesauce]

1 hour ago, xrbrevin said:

bent pin in the socket?

Sadly, no.  All SIO pins and sockets on motherboard, cables and peripherals all look straight and clean.  Cheers friend!

[+kheller2]

Assuming your 810s are sort of working, cable up one of them to the XL as drive one.

Turn power off XL and 810.

Turn on 810 and wait for ready light to go out.

Turn on XL.

 

if you don't get a boot error, repeat with 2nd 810, different cable, different port.

 

The XL should puke and give you boot errors when turned on with a working floppy set to 1 with nothing in the drive.

Assuming you set the dip switches properly.

 

It is interesting that you can save to tape properly... that means data in/out and motor control are working

 

 

[xrbrevin]

the common factor in all this appears to be the 800XL itself.

some understanding of the SIO operations may be required, i have never had a fault like this so unfortunately my knowledge is limited.

the pinout is as follows:

                             1 1 
                     2 4 6 8 0 2 
                     ----------- 
                    /o o o o o o\ 
                   /o o o o o o o\ 
                  ----------------- 
                    1 3 5 7 9 1 1 
                              1 3 

       1  clock in (to computer) 
       2  clock out 
       3  data in 
       4  GND 
       5  data out 
       6  GND 
       7  command (active low) 
       8  cassette motor control 
       9  proceed (active low) 
      10  +5V/ready 
      11  audio in 
      12  +12V (400/800) 
      13  interrupt (active low) 

when you play your recorded tape on an audio player, can you hear audible data?

the fact that the csave operation completed suggests that your data out, cassette motor control and command are working. the fact that you do not hear the lead-in tone and data sounds when attempting loading suggests that pin 11 could be faulty but i dont think it is the only issue here.

do you have a multimeter? some SIO connectors can be a tight fit and it is possible that 'flex' may have cracked a solder joint to the PCB. if poss, check continuity of pins and move on to check the components that are in line after the pins.

if you search the forum topics, there are some SIO mods out there that require removal of certain capacitors and adding a resistor. so if a component has failed you may find a solution just by removing it?

hope this helps but hopefully someone with more knowledge can advise?

 

[Porkchops & Applesauce]

42 minutes ago, kheller2 said:

The XL should puke and give you boot errors when turned on with a working floppy set to 1 with nothing in the drive.

Assuming you set the dip switches properly.

Oh yeah, I remember that now, the repeating boot error message!  Man, it's been so long, 20+ years when I put this machine in storage because of this problem I'm still having that I've forgotten much of how this thing works.  So sad.

 

I get nothing.  The 800XL acts like the drives don't exist, and boots to READY prompt.  I've hooked both drives up separately, set as D1, using different cables and ports.  Same issue.  By all accounts the drives seem to be working.  Turn them on - the power LED comes on, busy light stays on briefly while the hub and stepper motors adjust.  I'm working under the assumption all my peripherals, power supplies and IO cables are good.

 

It's odd because there is some communication happening via the SIO, at least with regard to the 1010 cassette motor control.

 

Cheers friend!

[_The Doctor__]

Pokey and PIA is where I'd start, clean and reseat any and all socketd chips, push them in before pulling them up and de oxit

 

Then see what happens...

[Porkchops & Applesauce]

1 hour ago, xrbrevin said:

when you play your recorded tape on an audio player, can you hear audible data?

the fact that the csave operation completed suggests that your data out, cassette motor control and command are working.

Thanks again for the help and useful pin diagram.

 

I've verified using a tape player that no audio is being recorded during CSAVE.  No data out?  When I try to CLOAD a commercially purchased cassette (confirmed data via audio player) I'll get Error 140.  No data in?  However, CSAVE and CLOAD does activate the cassette motor, so at least I know some communication is working.

 

I can confirm there is continuity at least between where the SIO socket is soldered to the board and the end of a SIO cable.

 

Cheers friend!

[AtariGeezer]

If you have sound in the self tests, then it seems to be narrowed down to a bad PIA 6520 IC. Atari Part #C014795...

[Porkchops & Applesauce]

35 minutes ago, _The Doctor__ said:

Pokey and PIA is where I'd start, clean and reseat any and all socketd chips, push them in before pulling them up and de oxit

 

Then see what happens...

Thanks for the tip!  I've pulled every socket chip, blasted the motherboard top and bottom with WD-40 contact cleaner, cleaned every chip contact with a soft toothbrush and 99.9% isopropyl alcohol, and reseated all the chips.  Same problem

[xrbrevin]

if you have to replace it, the PIA is a low cost universal 'off the shelf' part. you dont have to buy an atari branded one.

just make sure you get the right speed rating:

 

[_The Doctor__]

No corroded or broken traces/ bad solder joints, all sockets strong and all contacts in their holes looked normal?

No bulging capacitors etc...

Do you have access to any pbi devices

 

any one nearby to try chip swap of Pokey, PIA, or possibly moving the ram around... the PIA is cheap on alibab amazon etc... the pokey from 7800 cartridge possibly, arcade video cabinet or best, B&C, ben, MyAtari etc... Atari Freaks online shops

 

 

Edited September 23, 2019 by _The Doctor__

[+DrVenkman]

Setting aside the cassette issues, since nearly all Atari cassette drive belts go bad over time and turn to goo, let’s talk about your disk issues. Have you actually booted DOS first before you’re trying to save or load BASIC files from disk?

[Porkchops & Applesauce]

1 hour ago, DrVenkman said:

Have you actually booted DOS

Sadly, it seems I'm unable to communicate with my disk drives. Computer goes straight to READY prompt when either/both drives are connected.  Cheers!

[Porkchops & Applesauce]

1 hour ago, _The Doctor__ said:

No corroded or broken traces/ bad solder joints, all sockets strong and all contacts in their holes looked normal?

No bulging capacitors etc...

Do you have access to any pbi devices

Thanks for the tips.  There is nothing my admittedly untrained eye can see that's wrong. Unfortunately I don't readily have access to a PBI device, or chips to swap out.

Edited September 23, 2019 by Porkchops & Applesauce
uploaded board pics

[Porkchops & Applesauce]

Thanks everyone!  I think I'll start by replacing the PIA chip first and go from there.  The only thing that gives me pause that might not be the problem is because I have full use of my joystick with a cartridge game.  I'll keep everyone posted and let you know how it goes.  For now, please enjoy this pic of my gear as a thank you for all your advise and support!  Let's hope this classic lives to see another day.  Cheers!

[_The Doctor__]

while your in there next time make sure to pull the speed limiting caps for the sio lines...

[Porkchops & Applesauce]

1 minute ago, _The Doctor__ said:

while your in there next time make sure to pull the speed limiting caps for the sio lines...

What's this magic you speak of?

[Caterpiggle]

Maybe it has do with 2 yellow wires aftermarket ?

[_The Doctor__]

The wires are common factory bodge

Edited September 23, 2019 by _The Doctor__

[Porkchops & Applesauce]

4 minutes ago, Caterpiggle said:

Maybe it has do with 2 yellow wires aftermarket ?

Nope. I bought this computer new in the 80's, and have made zero modifications to it.

[_The Doctor__]

clean and work the drive selector switches... take care to connect all sio cords with no power cords plugged into wall, plug the power to the devices before the wall.... sometimes 810's selector switches get funky and gunky sitting around, and the sio being plugged/ power connected but no one can still clobber id select chip sometimes...

 

Thats about it till you can chip swap...

[Caterpiggle]

Hello _The Doctor_

 

That is strange, almost none of mine 800XL has that yellow wires. Strange enough ...