• Please review our updated Terms and Rules here

Problems after replacing CMOS battery DS12887 in Compaq Deskpro 286e

Oops, looks like I missed a few replies along the way...

I thought that 40 posts ago, after you initially replaced the RTC and ran setup, everything was working fine and the only problem was the modem IRQ not being recognized; did I get that wrong and was there a problem with the HD? If it was working and Fdisk (and chkdsk?) was happy, why change anything? If you change it back to 43 does it work again? I don't see why you're concerned with using the full HD capacity; I'd think the important thing is to get it working again the way it was, no?

But I take it that at least we don't have to worry about the HD contents and that you're sure that you can easily recreate it if you reformat the HD?
 
Last edited:
Hi MikeS:

Thank you for your follow-up.

I'd like to respond to your questions from Posts #41 and #41 below. My responses are preceded with “à”. I also ask a few new questions.

POST #40:

Yes, the 12887 is intended to be a direct replacement for the 1287.

à QUESTION-1: Could the fact I have installed the 12887+ rather than the 12887 be the cause of the IRQ issue with the modem?

Wuld sure be nice if you could back up that hard disk, but I suppose you don't have the means to do that? Would you be able to recreate it from original disks if you had to replace it?

à Yes. I have the Honeywell application that I could reinstall – and at this point, I would only install that application if I could get this up and running. What has me in the cold sweats is that I can’t boot from the Compaq MS DOS v3.31 disk… (Please see Post #31). QUESTION-2: Do you think there is a chance in finding another copy of the OS somewhere?

You’ve got the modem in front of you and I hate to doubt you, but are you sure there are no jumpers or switches? On an MB2400 I'd kind of expect three jumpers down near the edge connector, or, less likely, a small switch block that doesn't really look like a switch at a fast glance.

à There are jumpers just as you say. It appears they are configured as shown below (unfortunately I can’t seem to include any attachments so bear with the crude graphic):

- - - - - - - - - Pins
__ __ __ Jumpers


Worst case I'd think that you could replace the whole computer with something like a 16MHz 386 which would allow use of a more modern HD and shouldn't be too hard to find; unfortunately I think your motherboard is not a standard configuration so you'd have to replace the case as well which of course adds substantial shipping costs.

à At this point I would consider replacing the box with a more standard unit. Any thoughts on a source and cost?

Also, isn't your monitor nonstandard as well (12V DIN plug instead of 110VAC)?
à The monitor I’m using is an “NEC Multisync 2A”.

If you can't get anywhere with the modem I could probably send you another one to try.

à Thank you – I would appreciate that tremendously when we get to that point

It'd certainly be a shame if you had to replace the Honeywell end as well just because of a simple problem with that Deskpro.

à I agree… All this effort is being taken to prevent the Honeywell replacement at this time. I know this will be required at some point – hopefully in the future when a revenue stream can support it…


POST #41:

I thought that 40 posts ago, after you initially replaced the RTC and ran setup, everything was working fine and the only problem was the modem IRQ not being recognized; did I get that wrong and was there a problem with the HD?

à There appeared to be a problem getting the HD to be recognized after replacing the RTC and running the SETUP program. (Please refer to my Post #15: Page-2, 5th Paragraph from the bottom, beginning with “Here’s what I did from the start:”). Not sure what Norton Disk Dr did, but after running it, I could boot (but experienced some intermittent “quirkiness” – i.e., 1-IRQ failure issue; 2-if I booted from the A: drive, changed drives to C: drive, and changed directory from the root directory to some other, I would only see the C>. [ i.e., “A> C:” resulted in “C>”. When I attempted to change directories say to Bitcom, “C> CD Bitcom” the result was “C>” rather than “C> Bitcom”, and I was in the Bitcom directory as I performed a DIR to confirm])


If it was working and Fdisk (and chkdsk?) was happy, why change anything? If you change it back to 43 does it work again? I don't see why you're concerned with using the full HD capacity; I'd think the important thing is to get it working again the way it was, no?

à Despite the IRQ failure and quirky issues mentioned above, it was working ( I did not run CHDSK). I could try to run SETUP again and change to Type 43. I assumed that the incorrect drive Type designation may have resulted in the modem IRQ error message due to some logic glitch. QUESTION-3: Is this possible, or is the drive Type deignation only addressing full HD capacity? My understanding from something I read was that incorrect HD Type could result in a potential slew of problems…

But I take it that at least we don't have to worry about the HD contents and that you're sure that you can easily recreate it if you reformat the HD?

à Yes I can recreate it as long as I have a good copy of my OS…

Please let me kow if you have any additional questions. And thanks once again for your assistance.
 
MikeS:

The graphic of the modem jumpers did not reproduce accurately...

There are three sets of three pins. Jumpers are placed on pins 1&2 of each set of three pins.
 
To All:

Another Correction (probably obviuos, but want to confirm)

In my Post #22 (page-3) I said:

"I ran SETUP, changed drive Type to "43 - 528MB", and saved changes."

This should have read, "I ran SETUP, changed drive Type to "42 - 528MB", and saved changes." This was the closest Drive Type (also noted by Unknown_K).
 
Current Status:

I have been advised that the "+" suffix on the DS12887 chip indicates it is to be "lead free". That hopefully removes one variable...

This morning I entered SETUP and changed Drive Type from 42 (528MB) to 17 (40MB), 22 (40MB), and back to 43 (40MB) repectively. Here are the results:

Type 42 (528MB): Non-system Disk Error
Type 17 (40MB) Error loading operating system
Type 22 (40MB): Non-system disk error
Type 43 (40MB): Booted fine to Drive C

Ran TEST from User Diagnostic Disk and modem still shows as "COM2 at IRQ?", and still failed internal loopback test.

I tried to boot the system from the Compaq MS-DOS Operating System Disk, and again received the "Non-system Disk Error" message. I tried to run Norton Disk Dr. from the floppy as I had done at the start of this process, and also received the “Non-system Disk error" message.

I ran Norton Disk Dr. from the HD to diagnose the MS-DOS diskette and everything appears to be fine...

It appears that there have been coincidental cascading hardware and software failures that I can't explain...

Any further thoughts?

Booch
 
Sounds like after 45 posts we're back to where we started, although it looks like you may have damaged the boot record on the diskette along the way. If you're certain that it's the same DOS version on the diskette and hard disk, boot the hard disk, insert the floppy, and type "SYS A:" and see if the floppy boots after that; also check that there is a command.com file on the floppy.

BTW, what does CHKDSK have to say about the HD now that it's type 43 again?

In answer to your question, yes, a wrong HD type can indeed cause problems but I can't imagine how it would affect the modem IRQ.

Incidentally, it is not so much the size of the HD that is important (as long as it's not smaller than the BIOS setting) but the geometry; there are utilities that could report what the geometries of your different BIOS options are but unfortunately I don't think you have a way of getting them on to the Compaq's disk (am I right?)

Back to the modem:

I understand you know how to change the onboard com port to com2; I would remove the modem card and try that, and make sure the diagnostic says what you'd expect.

Unfortunately I don't have specific jumper settings for the MB2400, but I'd try moving all three jumpers to the other position, reinstall it (with onboard still set to com2) and see what the diagnostics have to say.
 
Last edited:
Thanks for your guidance MikeS.

I will address your recommendations.

Knowing now that it is unlikely the DS12887+ chip or the drive type is affecting the modem IRQ issue; and knowing that no MB dip switch or modem jumpers have been changed from a known "good state" of operation to result in this problem; it appears I have a modem failure. Would you concur - or is there still some possible motherboard or OS failure that could be the root of this problem?

Assuming it is the modem, and you have been gracious in offering to possibly let me try an alternate, would that be a next step? If so, we can work out the arrangements off line. You can reach me at btd1082@hotmail.com if this is still a possibility. If not - any suggestions as to best source would be appreciated.
Booch
 
Booch said:
Assuming it is the modem, and you have been gracious in offering to possibly let me try an alternate, would that be a next step? If so, we can work out the arrangements off line. You can reach me at btd1082@hotmail.com if this is still a possibility. If not - any suggestions as to best source would be appreciated.
Booch
Click to expand...
No problem, but if you try what I suggested, i.e. swap com1 and com2, we might get an idea of whether it's the modem or something on the motherboard.

As a related aside: can the software be reconfigured to use com1 instead of com2? If so, and it turns out the problem's on the motherboard, then you'd be in business.

By the way, the IRQ3 signal is the 7th connection on the rear of the modem card, counting from the front end (opposite from the bracket and jacks) and it probably connects to one of the (jumpered) jumper pins; have a look just in case it or the matching fingers in the socket have been damaged in some way.

Finally, have you actually tried to use the modem and/or the software? It would not be the first time that a diagnostic program lied...
 
Last edited:
Mike S:

Will do. I will address these recommendations late afternoon and report back,

I had tried the Honeywell communications program after the DS12887 replacement and I can connect to the Building Control. The data exchange begins, however, I repeatedly loose connection. This is what led me to do the diagnostic and find the "IRQ?" and failed internal loopback test. Prior to the chip replacement all worked seamlessly...
 
Looks like the old configuration had something moved so that the modem worked, you need to figure out what was set up differently in the CMOS.
 
I really don't want to intervene here when you all are doing such good work. But -

The RTC module on the 286E doesn't hold much in its memory--basically hard and floppy drive types, amount of memory and the type of the display adapter. It does not contain IRQ configuration information, port settings or anything else that could affect the operation of the modem. (I'm not really telling you anything that you don't already know).

However, SW24 and 25 on the motherboard do dictate (in a hardwired way) what connects to IRQ3 and IRQ4. If your (internal) modem is using IRQ3, then both should be either on (no serial port IRQs enabled) or both off (COM1: enabled on IRQ4). Unless you're using the built-in bus mouse, E4 should have pins 1&2 jumpered to disable the bus mouse.

That's pretty much it. If your modem fails the IRQ3 test and it's an internal modem, you'll probably end up replacing it or checking it for a configuration error (you didn't say what type and brand it was, as far as I can tell). Fortunately, ISA modems are still as plentiful as bedbugs in a flophouse.

If it's an external modem (hooked to COM2: ), then you'll want to enable COM2: IRQ3 by setting SW24 on and SW25 off.

That's about all I have to contribute on this one. Pardon me for butting in.
 
You know your opinions and observations are always welcome, Chuck.

Yeah, I don't see how the CMOS settings could possibly affect the modem and no other switches or settings other than the BIOS had been changed AFAIK when it stopped working. The OP did check the com port switches anyway, but maybe not the ones you mention. He did say a couple of times that it's a Cardinal MB2400.

For all we know the diagnostics are lying and it's actually working fine, and the problem is a bad line or connection at one end or the other; maybe just replacing the modem would avoid wasting even more time trying to figure out just where the problem lies...
 
Good Morning:

I want to thak you alll for your continued support with this problem...

After reading the last few posts, I did not make any changes to any jumpers or switches. I did run thru the 4-permutations on SW-2 on the MB as indicated in my Post #15. All of the switch settings were factory defaults when I started, and that is where they are now. The only thing I realized is I indicated a specific "ON" or "OFF" position in my Post, and I believe my comments are just the opposite of reality. I initially assumed the status of the DIP was dictated by the "red" side of the DIP. It appears to be just the opposite. Bottom line – all original factory settings are in place, and this condition is exactly what was in place when the system was known to function properly.

I attempted to connect to the Honeywell system this morning. The communications software only allows for a modem on COM1 or COM2. It is set for COM2.
When I initiated the command to receive status and history from the control, the modem initialized; received an audible dial tone; dialed the facility #; initially connected and then lost connection. I retried the process and was able to connect a bit longer, however, got a security code mismatch and the system terminated again. When all of this started, I reinstalled the Honeywell software nto an alternate directory to see if the instance I was using was corrupt. Both installs produce the same result.

Mike implied the problem might be related to a line or control issue at the other end... I will be calling AT&T today to confirm line integrity. If the second suspicion is true, well…

Any other recommendations at this stage? Modem replacement or not?

Booch
 
Booch, I'd try a new modem. Fortunately, as far as I can determine, there's nothing special about the Cardinal that you have. Search for "ISA modem" on eBay, and you'll find modem cards going begging. Nobody wants 'em. Heck, I couldn't even give away external modems, much less internal ones when I tried here.

Whatever you do, however, don't get a so-called "Windows modem". They're not that plentiful on the ground, but they will work only with appropriate driver software under Windows.
 
Hi Chuck(G):

Thanks for your help - will pursue a DOS based internal card.

Regards,

Booch
 
Booch said:
Hi Chuck(G):

Thanks for your help - will pursue a DOS based internal card.

Regards,

Booch
Click to expand...
Have a look around; it'd probably be cheaper getting one in the US than shipping from Canada, but if you can't find a bargain let me know.

Guess you really don't want to try swapping com port assignments? Probably just another waste of time though, it does sound like a problem with the modem. I'll have to try that; I would have thought that if the IRQ isn't recognized it wouldn't work at all, so maybe your diagnostic program is lying...
 
MikeS, Chuck(G), Unknown_K, et.al.:

I want to thank you all your your outstanding, prompt and ongoing support!

I am hopeful the modem swap will correct the problem. Will report the final outcome once complete.

If it turns out to be the Honeywell gear... well... I may just pack it in and try to get a job on a fishing boat in Key West...

Many thanks once again for all your guidance!

Regards,

Booch
 
I probably have an internal 2400 baud modem here somewhere you can have for shipping, with jumpers for setup (should be for something that old).
 
You must log in or register to reply here.
Back
Top