Struggling with Atari 800 + 1050s

[mutil8]

Hi - pretty sure this has been covered somewhere, however I cannot seem to find a solution. In a nutshell, my atari 800 does not seem to recognize a 1050 drive.

 

Recently unpacked an 800 that has been boxed up for decades. worked perfectly as did the 1050 drive when it had been packed away.

 

Started by testing the system w game cart and basic cart - everything so far worked fine. keyboard, video output all looks good.

 

However after hooking up the 1050 drive with power cord and sio cord I ran into a road block. Turning on the drive results in power and busy light coming on, then busy light going off.

Inserting dos 2.5 disk results in busy light coming on again briefly as disk spins. At this point I turn on the 800 itself but disk drive does not become active (no disk spin or busy light).

With basic cart in and typing dos  computer goes to memo pad not dos menu. tried 2 dos disks and a sparta dos disk.

 

I felt at this point possibly all my 5 1/4 disks were bad, however after discussing this with owner of best electronics he felt this was unlikely even after being stored for decades.

I took the drive apart, looked for obvious internal damage and cleaned the head w alcohol. Tested again same result.  switched power supply same result.

 

At this point it seemed to me most likely issue was with drive mechanics or electronics that I couldnt identify let alone repair. 

Got onto Ebay bought another 1050 seller claims is tested and working. After a week drive arrived today - hooked up and same result. 

Switched the sio cord to one that came w replacement drive - same result.

 

So no matter what computer does not seem to recognize either drive. Both drives have selection switches in back set to left (drive 1).

Only hooked up 1 drive to computer at a time. Both act and yield the same.

 

So there is something simple I am doing wrong, all my 5 1/4 disks are bad, both drives are bad (seems unlikely) or ....?

 

 

 

 

[Beeblebrox]

I've seen this behaviour reported before with the drive. It's likely a bad IC inside.

 

You may wanna begin with this thread which starts to go into related problems.

 

 

Edited December 10, 2022 by Beeblebrox

[Peri Noid]

I guess you checked this drive with another Atari machine to make sure it's the drive problem and not the computer's, didn't you?

It't a pretty common fault that the SIO buffer of a 1050 breaks and the drive seems to be invisible to the computer. This chip must be replaced.

 

[mutil8]

38 minutes ago, Peri Noid said:

I guess you checked this drive with another Atari machine to make sure it's the drive problem and not the computer's, didn't you?

It't a pretty common fault that the SIO buffer of a 1050 breaks and the drive seems to be invisible to the computer. This chip must be replaced.

 

I have not. I currently only have the atari 800 to test/operate. I do recall owner of best electronics mentioning that sio port could be an issue. Of course he also listed 10 other possible issues.

After getting 2nd drive and getting exact same results I do suspect problem is not with the drives themselves. So def could be sio port issue. It does puzzle me that computer/disk drive was working fine 

when packed up decades ago - would just time alone cause sio buffer chip to go bad?

 

Edited December 10, 2022 by mutil8

[TGB1718]

As you suspect it's highly likely it's your 800 that's at fault.

 

Are the chips socketed, I think they are in the 800, so could be just a bit of corrosion on the legs of

the IC's, I would carefully ease out POKEY and PIA chip and reseat them, an easy way to resolve

the issue if that's all it is.

 

Both POKEY and PIA are the large chips on the main board

[Peri Noid]

43 minutes ago, mutil8 said:

So def could be sio port issue.

It's not common but possible that your Pokey went bad as far as SIO is considered. You'd need a verified good working one to swap and check.

I have 2 like this. They do not allow for any SIO transfers but play just fine - so I use them as second sound chips in stereos.

[bfollowell]

It's certainly not out of the realm of possibility that your disks are bad, but I seriously doubt all of them are bad. I've not taken any really special care of mine over the past 35-40 years. Mine have been sealed up in boxes and stored in one basement or garage or other over the years and when I started pulling mine out a couple of years ago, I was surprised at how many still worked without any issues whatsoever. I'd guesstimate that I run about a 95% success rate with my old disks.

 

Good luck.

 

Edited December 10, 2022 by bfollowell

[Peri Noid]

If it was a disk fault, the drive would try to load them anyway. If there's no reaction, the problem is somewhere else.

 

@mutil8: Did you check/clean your SIO cord? Maybe it's simply dirty/oxidized and therefore there's no proper connection?

Edited December 10, 2022 by Peri Noid

[mutil8]

First off I want to thank all you guys for such quick replies - wasnt expecting that. especially 4 am here in california.

 

SIO cord  - have not cleaned it, however after purchasing 2nd drive I now have 2 sio cord and tried both of them - same result. So for now I will rule out bad sio cord as an issue.

Bad disks - from what I have read here as well as told by best electronics owner I will assume this is not the issue. Still a possiblity obviously.

 

Had zero clue that pokey or pia chips would affect SIO port, I have always been software guy/programmer never hardware.

As per suggestion I am going to take the 800 case apart look inside and reseat chips.

 

honestly it felt from the very start that the drive was trying to work - it comes on spins, accepts disk fine and spins again etc. And just sounds right. 

Now w 2nd drive they both behave exactly the same. But turning on the computer, nothing happens with the drive.

[mutil8]

OK I think I identified the problem - while struggling to disassemble the 800 and remove bottom RF shield, I noticed something didnt look right with the SIO port.

Closer inspection I could barely detect a bent pin. Tried to straighten the pin and it immediately broke off (was barely hanging on).

This is not an easy repair for a non hardware person, requires desoldering SIO unit and soldering in a replacement on pins that are VERY close together.

Too bad as everything else works fine, but I think best solution at this point is to buy another atari 8 bit. Man i thought I was going to just unpack this thing, plug in mac/65, and 

try to remember 6502. Sure took me a lot of time and $ to identify a simple problem.

[Vyvyan B.]

Have you checked for broken SIO pins in the 800? Also could be a wonky connection from the motherboard edge connector to the power board.

[+kheller2]

Picture please of the broken sio port.  We can tell if that pin is needed or not, or would be related to the problem at hand.  1050 needs Data In, Out, Command and +5 Ready.  

[Mclaneinc]

32 minutes ago, mutil8 said:

OK I think I identified the problem - while struggling to disassemble the 800 and remove bottom RF shield, I noticed something didnt look right with the SIO port.

Closer inspection I could barely detect a bent pin. Tried to straighten the pin and it immediately broke off (was barely hanging on).

This is not an easy repair for a non hardware person, requires desoldering SIO unit and soldering in a replacement on pins that are VERY close together.

Too bad as everything else works fine, but I think best solution at this point is to buy another atari 8 bit. Man i thought I was going to just unpack this thing, plug in mac/65, and 

try to remember 6502. Sure took me a lot of time and $ to identify a simple problem.

In cases like a broken pin it's best to disclose where you are (not your door number )

 

Often there are people that may be able to help..

[mutil8]

ok here it is. not 1 but 2 broken pins. not sure how it happened as i seem to remember the sio cable going on smoothly.

Just discovered 2nd pin bent - again tried to straighten it and it broke off immediately.

this pins seem very fragile, I am suprised this not a common issue with any of these sio ports.

[Vyvyan B.]

Ahhh, missed it by two minutes 😄 You can get a replacement jack from VCC

 

https://www.vintagecomputercenter.com/product/sio-replacement-socket

[Beeblebrox]

Certainly fixable and worth it. 800's are comparatively rare and certainly worth the effort for a small fix like this to get it back running. I am sure they'll be someone nearby who can assist 

 

 

[+DrVenkman]

49 minutes ago, Vyvyan B. said:

Ahhh, missed it by two minutes 😄 You can get a replacement jack from VCC

 

https://www.vintagecomputercenter.com/product/sio-replacement-socket

Act fast - @Gavin1968 is closing down his store very soon. I’ve already seen several posts from him on the FB Atari groups. 

 

However, there are still options. In recent years, several folks have either 3D printed or even had injection molded SIO connectors made in medium-sized runs. Someone may have a spare they can sell you for a few dollars, or you could find a damaged or unusable device like a modern to salvage the connector. If you don’t have a desoldering station, removing all 13 pins without damage would be a tedious task but it can be done. 

[bfollowell]

And like someone else mentioned, depending on where you're located, there's a good chance you may have someone close enough to lend a hand with the repair. Heck, California was definitely Atari-land back in the day, and to some degree it still is. We have a lot of users out there. If I were close, I'd offer to fix it for free as long as you bought the SIO port, but 800s are pretty fragile these days and with shipping costs up, it would be a big expense to ship all the way to southern Indiana. I'm sure someone relatively close to you will offer up their services though, assuming there is someone relatively close.

 

[TGB1718]

Just a thought, the SIO connector is on the power supply board, it might be easier to replace the whole board

if you can get one, no soldering required to remove it.

[+bf2k+]

If you want to ship me the board, I can replace the socket... I have some here.

 

Cheaper to ship the board than the whole computer but that's your call.

 

I'll replace it for $40 + you pay shipping.  I'm in the US.

[Vyvyan B.]

1 hour ago, DrVenkman said:

Act fast - @Gavin1968 is closing down his store very soon.

He should let someone else take over the business from him. There doesn't seem to be many places in the states to buy from and shipping from the UK and EU is horrendous.

[bfollowell]

47 minutes ago, bf2k+ said:

If you want to ship me the board, I can replace the socket... I have some here.

 

Cheaper to ship the board than the whole computer but that's your call.

 

I'll replace it for $40 + you pay shipping.  I'm in the US.

 

Good idea. That never occurred to me. I'd have offered, but since you already have, there's no need. It seems like a good solution.

 

If he'd rather buy NOS, B&C has "new" Atari 800 power boards going for $48.

https://www.ebay.com/itm/130888127552

 

[+bf2k+]

2 hours ago, bfollowell said:

 

If he'd rather buy NOS, B&C has "new" Atari 800 power boards going for $48.

https://www.ebay.com/itm/130888127552

 

That sounds like a better idea... if it was me, that's what I'd do. 

[Vyvyan B.]

He could replace the broken pins with a couple of sewing needles as noted in another thread from a few weeks back. I fixed a 400 SIO with a piece of something or other I got at home depot in the electrical section.

[mutil8]

OK - thanks guys - I will go the route of purchasing a power supply board. Would never have realized this was an option without the help.

 

Its weird, but this takes me all the way back to my start. Atari has always been a struggle for me. My first computer was a 400. Couldnt get anywhere with it.

Next computer was a apple IIe. learned 6502 (barely), did some minor consulting programming with it, and then a job due to it.

 

and still to this day I view the apple 8 bit line easier to figure out and program on than the atari 8 bit.