IBM PC Portable 5155 - Did an XTIDE kill my QuadRam Quadboard?

[Taffer]

I recently picked up a near-perfect condition IBM 5155 in original box.

After unboxing (the keyboard is in a separate box to the unit), checking power supply voltage and verifying no shorted tants on mobo or any cards, cleaning/lubing floppy drives, I booted it up.

It booted right up, counted to 640kb of RAM thanks to the Quadboard and I was off to the races. Then, hubris struck and I decided to upgrade it by adding an XTIDE card (lo-tech ISA XT CF V3), not in slot 8.

Upon boot, it generated 2 errors:
Error 101
Error 1801

After this reboot, the computer never counted past 256kb (which is what's on the mobo). No amount of changing slots, swapping RAM banks on the Quadboard etc has ever brought it back to life. I grabbed a SixPackPlus from my Compaq portable and it counted right up to 640kb (so presumably no RAM issue/bug on the motherboard).

Is it possible the XT-IDE killed the ROM on the Quadboard? Those 2 errors, never seen again, are very odd, especially 1801. Info on those errors below.

Thanks for help in advance!


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According to minuszerodegrees:

Some possible 101 causes:
• Motherboard's 8259 interrupt controller chip (includes supporting chips).
• Motherboard's 8253 timer chip (includes supporting chips).
• Motherboard's 8237 DMA controller chip (includes supporting chips).

Error 1801:
The POST found an extender card for the IBM 5161 Expansion Unit within the 5160.
Because of that, the POST made an assumption that a 5161 Expansion Unit is connected to the card.
The POST attempted to communicate with the 5161 and that communication failed.

Related diagram at here.

Some possible 1801 causes:
• 5161 Expansion Unit - not connected to the extender card in the host computer (e.g. missing cable) (e.g. loosely connected cable).
• 5161 Expansion Unit - not powered on (should to be powered on before the host computer is).
• 5161 Expansion Unit - faulty system board (backplane).
• 5161 Expansion Unit - power supply - faulty.
• 5161 Expansion Unit - power supply - has shut down due to a fault elsewhere in the 5161.
• 5161 Expansion Unit - power supply - has shut down due to inadequate loading.
• Cable - faulty.
• Cable - oxide build-up on the contacts within the two connectors.
• Extender card - faulty.
• Extender card - not seated correctly in host computer's ISA slot, or poor connection (e.g. dirty contacts).
• Extender card - oxide build-up on the contacts within the cable connector.
• Receiver card (within 5161) - wrong type. See here for a photo of the correct type.
• Receiver card (within 5161) - faulty.
• Receiver card (within 5161) - not seated correctly in 5161's ISA slot, or poor connection (e.g. dirty contacts).
• Receiver card (within 5161) - oxide build-up on the contacts within the cable connector.

Additional:	It is known that an 1801 error can sometimes be incorrectly triggered if an accelerator card is fitted.
	See the 'Accelerator cards in slot 8' section at here.

 

[jafir]

Just to confirm, you don’t have an extender card installed, right? Because if you do, and you don’t need it, I’d be interested in acquiring one.

Also I see that you have two of those quadram boards in the last photo. Do both have issues?

Also I wouldn’t expect a ram-only upgrade board to have a ROM.

 

[Taffer]

No, unfortunately. My white whales are the 5155 and the 5161/cards/cable. I've now speared the one but still looking for the other.
Yes, the bottom-most quadram is the one that came in the 5155; the other 2 top cards (Quadram and Techmar Captain) I pulled from my parts bin but I believed they are non-functional and sure enough they didn't work. Since the one in the 5155 was working at 640kb, I know it worked.

That's good news on the ROM, unless it being a multifunction card rather than a simple RAM expansion card means it would have one.

I guess what I'm asking is if there is some non-hardware damage that could have been done? I'm pretty good with hardware but very weak on ROMs/flashing etc. That 1801 error is really weird.

 

[modem7]

That's good news on the ROM, unless it being a multifunction card rather than a simple RAM expansion card means it would have one.

The vast majority of multi-function cards have no ROM.

Upon boot, it generated 2 errors:
Error 101
Error 1801

Those 2 errors, never seen again, are very odd, especially 1801.

Background: I am the author of minuszerodegrees.net

Over the past 20 plus years, I have done a lot of work with IBM 5150/5160 motherboards, out on the dining table. Experimentation, behaviour determination, recreating people's reported symptoms, writing and executing test code, etc.

On rare occasions (I guess every few years), part way through use of an 5150/5160 motherboard, the POST will display a 101 error at power-up. The sequence is the same: I turn off the power supply, wait 15 seconds, then turn on the power supply. The 101 error remains. I curse because the repair is something else that is now on large my to-do list. But, based on what I have learned, I turn off the power supply, but this time, leave it off for say, 10 minutes. Then I discover that the 101 error has disappeared. The power-off duration was the only variable that I changed. I put it down to a weird 'hiccup'.

I have yet to encounter an 1801 error.

After this reboot, the computer never counted past 256kb (which is what's on the mobo). No amount of changing slots, swapping RAM banks on the Quadboard etc has ever brought it back to life. I grabbed a SixPackPlus from my Compaq portable and it counted right up to 640kb (so presumably no RAM issue/bug on the motherboard).

So, the Quadboard failed, with the card's RAM chips ruled out as the faulty part of the card.

Do I think that adding the XT-IDE card caused the failure? No. I think it was coincidental. Maybe, at power-on time, a component on the Quadboard failed in a way that resulting in a voltage surge.

 

[modem7]

Those 2 errors, never seen again, are very odd, especially 1801.

Further re the 1801 error.

At my web site, I have, "The POST found an extender card for the IBM 5161 Expansion Unit within the 5160."
How does the POST know that an extender card is present?
The code is:

1. Write 5555h to I/O port 210h (210h = control port on an extender card).
2. Read back I/O port 210h.
3. If the data read back is 5555h, then repeat the write-then-read-back check using the data of AAAAh.
5. If the data read back is AAAAh, then consider an extender card to be present.

In essence, if the POST finds a register that has read-back capability, at I/O port 210h, the POST considers an extender card to be present, and then goes on to do the 1801 test.

Rhetorical: In your situation, was it that some kind of temporary 'hiccup' resulted in the write/reads of port 210h targeting a different port (one with read-back capability)?

 

[retroegde]

I just got a 5161 up and running and can confirm that with the Extender installed without the 5161 powered on it gives the 1801 error. Thank goodness for minuszerodegrees.net telling me the details on the error. I think that it is a design flaw because I won't always want to use the 5161 with my 5150. Maybe someone out there has a modified BIOS I could flash.

To whomever is interested in an Extender, I built a pair of the Tubetime.us replicas so I have one extra. I also have three PCBs since the minimum order from PCBWay is 5. I haven't built the receiver yet but I do have 5 of those PCBs as well. The receiver requires a part that you can no longer get so I have an original receiver. I do have some modern 150ns DS1005 that I plan on using on the replica. Worse case I can swap the belfuse to see if the replica works.

 

[Taffer]

Well, I've been playing around and have not been able to replicate that error, so I think modem7's supposition that it was a fluke is all that's left. I am annoyed I now have 4 dead RAM cards (2 Quadrams, 1 techmar captain, one IBM 128/640k though that's a 16bit and may not work anyway). I'll probably get one of those lotech 1mb cards and save the long slot in the 5155 for a sound card or other long card.

 

[jafir]

To whomever is interested in an Extender, I built a pair of the Tubetime.us replicas so I have one extra.

Are you looking to sell the extra? If so, where are you at and how much? Also how much for just a pcb? I’ve already got some of the receivers, they seem to stay in the 5161 and so don’t go missing.

 

[modem7]

Maybe someone out there has a modified BIOS I could flash.

I will modify the BIOS and PM that to you. Is it the 11/08/82 revision, or did someone upgrade it?

 

[retroegde]

Are you looking to sell the extra? If so, where are you at and how much? Also how much for just a pcb? I’ve already got some of the receivers, they seem to stay in the 5161 and so don’t go missing.

I need to dig into what I paid for the components on mouser. I'm great with selling at cost plus shipping. Are you able to DM me?

 

[Taffer]

I would be interested in the extender card as well if you have more than one or anything. Thanks

 

[jafir]

I sent one. I’m not sure if it will work or not, they might be restricted until you have at least 10 posts.