Technical questions for the MPC2000xl and the MPC2000
By DJASWIFT73 Tue May 24, 2022 11:39 am
My Scsi2SD was working fine, then it wasn't, after I bone-headedly left my Mpc on overnight (sd card damaged, maybe ?) Floppy drive still lights up, actually attempts to load off the floppy, but then I get this screen that looks like a bunch of codes. ANY CLUES ? I will post the pic when I figure out how to.
By DJASWIFT73 Tue May 24, 2022 11:47 am
The codes look like this :
AX:0000
BX:05E4
CX:0000
DX:0000
BP:00E4
PC:17F2 on left of screen.

And then on the right of screen it reads :
SI:0000
DI:7FFF
DS:491A
DS:491A
ES:491A
CS:3B7C
SS:538D SP:00C4

Anyone have an idea on what I need to do now, are these codes fixable, etc. I'm gonna try ANOTHER floppy that supposedly has the files I need for the Mpc 2000 classic, not XL, to boot from when it arrives...maybe try another micro sd too ? Lost at this point...all info welcomed...thanks in advance.
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By NearTao Tue May 24, 2022 12:16 pm
If I remember correctly, those are CPU register codes, and I'd imagine you'd be hard pressed to figure out what they mean. Effectively it is telling you that it cannot proceed further for some reason. Here are a few thoughts...

You said you left it on for an extended length of time. Generally this will heat things up a lot more, and can lead to expansion and contraction issues, so you may have loose cables, the firmware chips may have oxidized and are not fully connected, a solder joint may have gone bad... those sorts of problems.

Due to this kind of heat expansion/contraction issue, you'll see some people will take old computers, like Atari computers, and just drop them to "fix" them. Sometimes it is just enough force to kind of reseat a chip, nudge a ribbon cable to get electrical contact, or whatever... but obviously this isn't going to solve the root problem, which in this case is old/faulty connections... that just need to be cleaned.

Personally, if you're any good working on electronics, as well as careful and patient, I'd probably take the top off, and try and check one connection at a time. For example, unseat and reseat one of the firmware chips, and you may not even need to take it out of the socket, just pulling it up a little and pushing it back down may knock some of the crud off of the connection to get a proper electrical connection again. Similarly, a ribbon cable may have just come unseated from heat expansion and contraction, and just disconnecting and then replugging it back in properly could solve your problem.

Again though... I'll repeat this... just do *one* thing at a time, and turn it back on between adjustments. This way you can see if you are making things worse, they stay the same, or if they change, or they get better. Don't be afraid to take notes, record videos, or anything else... because you never know when you might capture something that you didn't think was a big deal but you notice later that can help solve the puzzle.

And yeah, all this older gear especially can be a hassle, but as long as you take it as a learning experience, and know when to walk away when you get frustrated, you'll absolutely learn something, and with any luck get it back to working again.
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By richie Wed Jun 29, 2022 11:14 am
Don't you love when you take the time to put together a concise response to not even get acknowledged for it?
By Smokeychuck Fri Jul 15, 2022 2:37 pm
This is a little bit old but what those “codes” are cpu registers as the previous commented said

Essentially that is a hexadecimal representation of the data held in the CPU’s registers when the panic occurred.

I have never witnessed a register dump on an MPC but that’s what it is.

Did you make any changes to the unit before it happened? Install anything, etc?


Do you have a floppy in the floppy drive or something plugged into the scsi?

I would start out by removing all your expansions (8 outs, fx) and remove any SCSI device or floppy disks in the disk drive. Try and boot it up and see if it still panics, if it does then it’s not caused by something on one of those components (like the processor trying to access something that has a bad connector and is sending back jibberish, causing the kernel to panic when trying to decode and execute the response)

Did the screen say anything like segfault or give an error code?