800XL Blue screen with a cursor.

[psykix]

Howdy all!

 

I recently retrieved an Atari 800XL and a 1050 drive from the parents loft.

 

The 1050 worked once and then the motor died - replaced the 47uf caps and it's alive again!

 

Just tried a Star Raiders cartridge and the 800XL went to self test. Powered off and now it just sits on blue screen with white cursor - I never get Ready on screen.

 

Any pointers where to start troubleshooting?

 

EDIT: Just to add.. now when I try the cartridge I just get a black screen (not no signal).

 

Cheers!

 

Edited April 20 by psykix

[Beeblebrox]

Bad ram can cause all manner of things  so it could be this. 

 

Also, if it were just the blue screen with white prompt square, a failing pokey chip or it's socket or traces and vias around it could this. 

 

Take a pic of the board and upload it. 

 

What ram have you got? Mtram? 

[psykix]

When it loaded to a self test I ran a mem test and it seemed to be ok. Doesn't mean it hasn't died since then mind you! Yeah MT RAM. Also there is some corrosion on 5th pin down of the keyboard ribbon cable which I gave a bit of a clean with IPA - not sure if that would stop Option key from working, because I can't get it to go into a self test using Option on boot.

 

I'm out now for the rest of the day so will have to pick this up again tomorrow!

 

Cheers for the fast reply!

 

 

[Rybags]

Maybe slightly lift and reseat the major ICs.

OS and Basic are the ones at top right near the serial plug (OS the bigger)

 

Though that photo looks like not much is socketed at all?

Edited April 20 by Rybags

[Beeblebrox]

2 minutes ago, Rybags said:

Maybe slightly lift and reseat the major ICs.

OS and Basic are the ones at top right near the serial plug (OS the bigger)

 

Though that photo looks like not much is socketed at all?

nothing is socketed on the board if you blow up the image.

[flashjazzcat]

Micron DRAMs (yet again). They should be socketed and replaced as a matter of routine, and doing so may well fix the machine.

 

[psykix]

Yeah, nothing is socketed. I’ll add sockets and change RAM as a first port of call. What RAM is recommended?

[xrbrevin]

this:

4464 dram

also known as 4164

[psykix]

5 hours ago, xrbrevin said:

this:

4464 dram

also known as 4164

Thanks! Was getting confused reading all the posts and a lot of the links to dram were no longer live.

 

 

[Rybags]

4464 - no.  That is the 4 bit x 64k DRAM.  Only used by XEGS and 2/4 chip 65 and 130XE.

[xrbrevin]

i thought that was 41464?

[Rybags]

Different numbers have been used to describe them.  Supposedly 4464, 41464 and 2464 are much the same thing.

I'm not sure on the exact reason, possibly when new chip carrier formats came out, or just different companies coming up with their own naming scheme.

[psykix]

Ugh.. so I ordered the wrong thing then?

 

Edit: Actually the ebay description says 800XL so I should be ok!

 

Edited April 21 by psykix

[xrbrevin]

it seems there is no standard part number - it varies by manufacturer!

we need an index of compatibles..

[Ricky Spanish]

all of these 64k chips should work in the 8-chip XL/XEs
PD4164,HM4864, HM4864A, HYB4164, LH2164, M5K416, MK4564, MB8264, MB8264A, MSM3764, MN4164, MT4264, TMM4164, TMM4164A, TMS4164,
4164.

[Rybags]

250ns is supposedly the maximul supported latency - though I don't think any DRam by that time was slower than 200.

[psykix]

I need some more advice on this! I ordered replacement DRAM and sockets but only the sockets have arrived so far. I also ordered a Super Salt diagnostic cart.

 

Diagnostic cart boots fine. It shows 32K RAM and no errors on the main screen. However.. the keyboard does not appear to be doing anything now - only the reset button appears to work so I can't press ? for instance to get to the help menu.

 

Any suggestions or do I just wait and proceed with DRAM replacement when it arrives? Dunno if that would stop the keyboard working or not.

 

Edit: I tell a lie - I set the cart to CPS diagnostic and can run the tests using the silver keys (option, start etc) - RAM passes, ROM passes. Keyboard doesn't work but it did do before the blue screen white cursor issue..

 

Edited April 25 by psykix

[TGB1718]

On 4/21/2024 at 9:01 PM, psykix said:

Ugh.. so I ordered the wrong thing then?

 

Edit: Actually the ebay description says 800XL so I should be ok!

They are very different chips, as @Rybags said, the 41464 is a 4 bit * 64K chip, the address pins are very different (and others)

to the 4164 which is a 1 bit * 64K chip.

I don't know if the 800XL had a model with 2 chips, but yours has 8 so it has the be the 4164 variant

 

I know that some 65XE, 130XE have either chip, but they are not interchangeable i.e. 2 or 4 for 65XE and 8 or 16 chip for 130XE

I believe that the XEGS also uses the 41464 2 chip memory.

 

Edited April 25 by TGB1718

[psykix]

The chips I ordered were 4164B so should be fine.

 

I'm beginning to suspect the Pokey chip though...

 

[Rybags]

The major different variant of 800XL is the later one which has Freddie.

It would make sense that they use the 1-bit DRams only since we didn't see the 4-bit chips until later on in the XE lifetime.

 

[Mq.]

On 4/20/2024 at 12:59 PM, psykix said:

blue screen with white cursor - I never get Ready on screen

This is typical behavior of Pokey damaged or absent. Don't touch the memory, it is probably ok.

[psykix]

16 hours ago, Mq. said:

This is typical behavior of Pokey damaged or absent. Don't touch the memory, it is probably ok.

Yeah, memory was changed and socketed. Made no difference. Removed Pokey and fitted a socket. Still the same. Already ordered a replacement.

[+nurmix]

I see you mentioned the keyboard is not responding now, but just in case.. when you get to the blue screen with white cursor, if you hit the BREAK key does the ready prompt appear?

 

I worked on an 800 a few months ago that would do the same thing, but a quick tap of the break key would bring up READY (or Memopad if you didn’t have a BASIC cartridge inserted).  It was a bad POKEY.  Replacing it fixed the issue.

 

If you don’t have another POKEY to try, I have heard of folks ‘reviving’ a failing POKEY with a heat gun, but have not tried it myself.  Ideally that would be done with the chip off the PCB, and since you socketed it, that’s an option.

[Beeblebrox]

Just to chime in here. 

 

Yesterday I returned to an old 600XL board I was fixing last year but had to park.

 

So after finding a bad CPU was one of the reasons I was getting a black screen, I actually got to a stage where I was getting the blue screen cursor and the bleep sound you get when loading a cassette (where the maxchine thought I was holding down the Start key).

 

My first thought was Pokey, so I swapped in a known working spare - no change. Second was replacing the 4051 chips. No change. Third was replacing the PIA with another PIA. Again, no change.

 

Being a 600XL it was all socketed, then my attention turned to the sockets. I replaced the original 40 pin sockets for pokey, but that made no difference. Then I replaced the socket for the PIA and the issue went away. So looked like a bad PIA socket or factory solder work related to that socket.

 

So perhaps have a look at the PIA as well as the Pokey.

 

Also, GTIA is worth looking at perhaps:

 

 

Edited Monday at 09:16 AM by Beeblebrox

[psykix]

BREAK didn't do anything. I tried blasting the Pokey with hot air but nada... Just waiting on replacement chip to arrive.

 

I'll socket the other chips and see what happens.

 

Just to add.. the sound test works on the Super Salt, so the Pokey is at least part working I guess?

Edited Monday at 09:22 AM by psykix