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Maxtor 7120AT jumper settings.

Sorry, bit of a neophyte at this. I don't expect to be doing this regularly; just trying to pull the data from this drive, one-and-done.
If you are in Australia, you have the option of posting the drive to me. Assuming that the drive is still okay, I can copy off the contents using old computers that I have.

Are you hearing (and feeling) the platters turning ?
 
If you are in Australia, you have the option of posting the drive to me. Assuming that the drive is still okay, I can copy off the contents using old computers that I have.

Are you hearing (and feeling) the platters turning ?

I'm in the USA, unfortunately. 😭 Yes, the platters are turning, thank goodness! It's the reason I'm hopeful the drive is still okay.

I pulled the drive out of an old 486 computer. The other option is I can try to get that computer up and running and just floppy disk the data off, but unfortunately the CMOS battery is shot and I have NO idea where it is on the motherboard to replace it. My Dad and I scouted all around the motherboard when he was still alive, and we never found anything that looks remotely like a CMOS battery. ¯\_(ツ)_/¯
 
If you can take pics of the motherboard, let's see if we can help, A working 486 would be handy to keep around anyway if you're getting into vintage computing.
 
Well, if it's any help....if you still have the 486, that was my first 486 hard disk and I still remember the CHS and can guide on the CMOS battery issue as well....

MAXTOR 7120AT
HEADS= 936
CYLINDERS = 16
SECTORS = 17
PRECOMP = 0 or 65535 (depending on your BIOS)
LANDZONE = 936

If you could not find a CMOS battery inside, did you see any chips that said "Dallas" or looked similar to below under a different name (more people made these chips than just Dallas, such as BENCHMARQ, Intersil, ST, and so on).

PS: I Can remember the CHS because my first 486 in 2001 had no CMOS battery for the first six months, and I had to put in those numbers EVERY TIME I used that computer. It was really the first computer I really did any actual serious work on past a memory upgrade.
 

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... but unfortunately the CMOS battery is shot and I have NO idea where it is on the motherboard to replace it. My Dad and I scouted all around the motherboard when he was still alive, and we never found anything that looks remotely like a CMOS battery.
... did you see any chips that said "Dallas" or looked similar to below under a different name (more people made these chips than just Dallas, such as BENCHMARQ, Intersil, ST, and so on).
Additional information for Sour Patrol: The pictured Dallas (and other) modules contain a battery.
 
Well, if it's any help....if you still have the 486, that was my first 486 hard disk and I still remember the CHS and can guide on the CMOS battery issue as well....

MAXTOR 7120AT
HEADS= 936
CYLINDERS = 16
SECTORS = 17
PRECOMP = 0 or 65535 (depending on your BIOS)
LANDZONE = 936

If you could not find a CMOS battery inside, did you see any chips that said "Dallas" or looked similar to below under a different name (more people made these chips than just Dallas, such as BENCHMARQ, Intersil, ST, and so on).

PS: I Can remember the CHS because my first 486 in 2001 had no CMOS battery for the first six months, and I had to put in those numbers EVERY TIME I used that computer. It was really the first computer I really did any actual serious work on past a memory upgrade.

Hey! I see the Dallas chip! What's the fix, do you think? Pull the mobo and unsolder that chip?
 
Hey! I see the Dallas chip! What's the fix, do you think? Pull the mobo and unsolder that chip?
WARNING: If you see a DS1287 being sold online, even unused, the battery in it may be depleted.

WARNING: Online, you may see text indicating that the DS1287 can be replaced by a xxxxxxxx. Sometimes that works and sometimes it does not. It depends on the motherboard/BIOS. More information about that is at [here].
 
Is there a trick to unsocketing the Dallas chip? It doesn't look like it's soldered directly to the motherboard; it's elevated and there's a black plastic rectangle sandwiched between it and the mobo, which I presume is the socket base. Every video I've looked at, the chip pulls out easily. But I've tried pulling it, levering it up, rocking it, and the most I can make it do is creak noisily. I don't want to go too far and damage the motherboard irreparably. Am I being overly cautious?

Would something like this work as replacement?

 
Is there a trick to unsocketing the Dallas chip? It doesn't look like it's soldered directly to the motherboard; it's elevated and there's a black plastic rectangle sandwiched between it and the mobo, which I presume is the socket base. Every video I've looked at, the chip pulls out easily. But I've tried pulling it, levering it up, rocking it, and the most I can make it do is creak noisily. I don't want to go too far and damage the motherboard irreparably. Am I being overly cautious?

Can you post more detailed pictures of this? But it sounds like you may have one that is not socketed and is soldered on, though it's possible it's socketed, but due to corrosion it's sort of welded into the socket. De-soldering maybe unavoidable.

Would something like this work as replacement?

It almost certainly will, but there is no way to know for sure until you try. But with a dremel and some patience, reworking your existing chip is not that hard.
 
That definitely looks socketed to me. So if it's not coming off, then you are probably dealing with corrosion on the pins hold it in. I'd not just yank on it, I'd work a small screw drive and gently try to pry it out a little at a time. Or else just desolder the whole thing from the board and plan to replace the socket once I get it off.
 
Is there a trick to unsocketing the Dallas chip? It doesn't look like it's soldered directly to the motherboard; it's elevated and there's a black plastic rectangle sandwiched between it and the mobo, which I presume is the socket base. Every video I've looked at, the chip pulls out easily. But I've tried pulling it, levering it up, rocking it, and the most I can make it do is creak noisily. I don't want to go too far and damage the motherboard irreparably.
Maybe it is in a socket, but because of its mass, the motherboard assemblers put a dab of glue underneath it.

Would something like this work as replacement?
I say possibly, not definitely.
Note in the eBay listing, the use of "should be compatible", not "is compatible".
 
I've replaced the chip. Now struggling to get into BIOS.

On bootup I'm greeted with this:

PhoenixBIOS(TM) E486 Version 1.00.07.S0
Copyright (C) 1985-1992 Phoenix Technologies Ltd.
All Rights Reserved

640k Base Memory
15360k Extended

000

BALLARD SYNERGY CAMcore (R), Copyright 1991, 1.602
... NCR SDMS

(0018): Invalid configuration information - run EISA configuration utility
(0025): No boot device available -
To retry boot press Spacebar

I think I need to get into BIOS to configure the boot device, correct?

I know it's possible to get into this damn BIOS; I've done it before. My Dad knew the right key combination when he was still alive, but getting through to him now would take a long-distance call... I've tried everything I can think of. Any ideas?
 
I've replaced the chip. Now struggling to get into BIOS.

On bootup I'm greeted with this:



I think I need to get into BIOS to configure the boot device, correct?

I know it's possible to get into this damn BIOS; I've done it before. My Dad knew the right key combination when he was still alive, but getting through to him now would take a long-distance call... I've tried everything I can think of. Any ideas?
Disregard, I figured it. Had to jump some pins on the motherboard to enable BIOS. Am now in BIOS attempting to determine proper hard drive settings.

Well, if it's any help....if you still have the 486, that was my first 486 hard disk and I still remember the CHS and can guide on the CMOS battery issue as well....

MAXTOR 7120AT
HEADS= 936
CYLINDERS = 16
SECTORS = 17
PRECOMP = 0 or 65535 (depending on your BIOS)
LANDZONE = 936

If you could not find a CMOS battery inside, did you see any chips that said "Dallas" or looked similar to below under a different name (more people made these chips than just Dallas, such as BENCHMARQ, Intersil, ST, and so on).

PS: I Can remember the CHS because my first 486 in 2001 had no CMOS battery for the first six months, and I had to put in those numbers EVERY TIME I used that computer. It was really the first computer I really did any actual serious work on past a memory upgrade.

Can you double check these settings? Cylinders and heads are reversed on every BIOS option I see. I have options for Types 1 through 49 and none of the options match that.

Here's where I'm at. The computer is a LP486E, which the almighty Google informs me is commonly known as a Panther.

I can get into BIOS. I can manually type in the CHS settings for the HDD. (I set Sec to 17 based on an old USENET post I dredged up from circa 1994; if anyone knows better, please let me know!)

However, I can't get the BIOS settings to stick. Every time I save settings and restart the computer, the BIOS reverts to default settings. When I go back into BIOS, a red message tells me there's an error with the memory settings, which I assume is the culprit. Photos below. I'm not sure what it's taking issue with; I've tried disabling Base Memory Above 512k, and it still gives me the red message.

20230915_230807.jpg
20230915_232453.jpg
20230915_232355.jpg
20230915_232404.jpg
20230915_232406.jpg
20230915_232408.jpg
 
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Disregard, I figured it. Had to jump some pins on the motherboard to enable BIOS.
That does not sound right.
Are you implying that in the late 90's, someone removed some kind of 'BIOS enable' jumper before the computer went into storage?
Or were you playing with jumpers as part of your recent investigation (before you discovered the Dallas module) ?

Here's where I'm at. The computer is a LP486E, which the almighty Google informs me is commonly known as a Panther.
However, I can't get the BIOS settings to stick. Every time I save settings and restart the computer, the BIOS reverts to default settings. ...
Looking online, I see a motherboard at [here] that has an alias of "Intel LP486E".
Presumably, the photo shows default jumper settings.
Are your jumpers set the same ?

1694842971861.png
 
I moved the jumper from pins 2-4 to pins 1-3 "Setup Enable." This allows F1 to take me into setup whose screenshots I posted above.

The last time my Dad and I mucked around with this computer was in 2019. I remember the two of us were able to load into BIOS and identify there was a problem with the CMOS battery, as the BIOS would not save settings. However, I don't recall either one of us changing the jumper settings on the motherboard.

lp486sx-diagram-64b557df6e74a236898523.jpg


Here is a picture I took of the jumper settings before jumping 1-3.

20230915_222506.jpg
 
In the photo just posted, pins 11-13 ("SYSTEM CONFIG KEEP") doesn't have a jumper on it. Have you tried a jumper there?

That was a good suggestion. I jumpered it, and BIOS keeps its settings... However, now instead of booting to "No boot device available", it boots to an error message that says "Missing operating system." My gut tells me this is a bad thing. Does this mean the drive has somehow been corrupted in the last 30 years and there's no data on it left to recover? Or is there still some slim hope that something's misconfigured and it can't find the master boot record?

I've tried the following settings:

Cyl / Hd / Pre / LZ / Sec / Size
936 / 16 / 0 / 936 / 17 / 124
1024 / 14 / 0 / 936 / 17 / 119
1024 / 14 / 0 / 1024 / 17 / 119

Here are jumper settings on the Maxtor 7120AT hard drive. I had the thought maybe I need to jump J19 and J20 both since it's a single drive, but I don't have another jumper cap:

20230916_135944.jpg
 
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