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286 Cmos battery

D

Darshevo

Experienced Member
Joined
Aug 9, 2009
Messages
206
Location
Eastern Washington
I was pretty dead set on pulling out either my Kaypro or Osborne tonight to play with it but when I went for it I found this old 286 that I had forgotten I'd picked up. Its made by DTK and has a Alphanetics mobo. When I turn it on it alerts me that the cmos battery is dead. I looked over the mobo as well as the disk controller card and do not see a traditional cmos battery (nickel or penny sized) anywhere on the mobo. Any push in the right direction of what I should be looking for would be greatly appreciated

-Lance
 
Look for a little boxy thing, it's a Dallas real time clock (rtc) and if it has one of those you can leave it plugged up and mybe on (correct me if I am wrong) and it'll charge itself up. Worth a shot.

Will the machine let you in at all? No Hit F1 to enter setup or anything like that?

Hope this helps!
 
I did indeed find the Dallas clock. From the time I made the inquiry until now it has been sitting plugged in. Earlier when I would turn it on it would tell me that the cmos was dead, press F1, enter new date/time info. It would ask me about the HD (which wasn't in the list of options) so I picked the one that was closest. On reset it went back to the same routine.

After letting it sit (plugged in) now when I turn it on it powers up, the HD spins and the light goes into a flickering routine that repeats about every 8 seconds. Oddly, no beeps and it doen't light the monitor.

Here is the motherboard installed: http://www.alternativetech.net/th99/m/A-B/33640.htm

I am going to disconnect the HD and see if that makes a difference in startup (since the exact drive wasn't in the list of 47 or so it gave me)

Its a Miniscribe 52mb model 3650

When I got this it had all 5 screws in the case and I have no reason to believe that anything inside has been messed with. If it was decommissioned due to age there shouldnt be a ton of mismatched parts in there screwing with me.

-Lance
 
Update: I went through and made sure all the cards, chips, cables etc were seated. In the process I found that the floppy cable was almost disconnected. I double checked everything and rebooted, came up again. Here is the exact text I get:

286 Bios (C) AMI for Bristol Research Corp

01024 KB OK

CMOS battery state low

*** RUN SETUP UTILITY ***
Press <F1> key to RESUME

(here I press F1

Want to run SETUP or DIAGS (Y/N)? (enter Y)

SETUP or DIAGS (1/2)? (enter 1)

It goes on to ask me date time info, HD and floppy info, then reboots which brings me back to the top again. I'll leave it plugged in over night and see if the Dallas chip takes a charge.

I'm off to do some research and see if I can find some DOS images I can put onto floppy. This unit has a 1.44 in it (according to the part number on google Epson SMD-300) So I am thinking I should be able to install a 3.5 in my p4, format with FAT and copy some OS files over? It'll be my next experiment

-Lance
 
Afraid the CMOS battery won't take a charge, Lance. It's a plain old lithum coin cell under the epoxy--it's not a rechargeable.

There are two basic approaches to fixing this. The first is to purchase a new DS12887/12887A and hope that it works with your motherboard. See:

Maxim App Note 503

The other is to grab a dremel and cut into the epoxy of your current clock chip and connect a new battery to it:

Here are some instructions.

Whatever you do, don't be tempted to buy a NOS DS1287--the battery has a shelf life and you most likely will find yourself in the same stew in short order.
 
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Thank you to NathanAllan and Chuck for the heads up on the Dallas chip. I have followed the easy steps given and am now CMOS happy. I had picked up an old P3 motherboard at a garage sale for a buck to rob the processor out of and just for fun I checked the battery in it, just a tad over 3 volts. A quick desolder of the socket, a couple wires, some over eager grinding with the dremel and:

battery01.JPG


And the finished product:

battery03.JPG


Next step will be to get a 3.5" into my P4 and see about getting a boot disk set up to do further testing with. Once I get to a DOS window then I will address the HD and how to get it recognized

Thanks again for the help

-Lance
 
The next wave

The next wave

Alrighty, the 286 is alive. I was out in the shop digging through boxes looking for an external USB 3.5" drive (with no luck) but did manage to find 2 disk cases full of 3.5 inch disks and 1 full of Mac 3.5's. I am watching a color demo called Mental Surgery on the test screen as I type. After a quick install of an internal 3.5 in my P4 I used a 3.3 boot disk image and 'Walla', Dos Prompt!

Now for my next quandries...

1. When using setup it only gives me options for 47 difference HD's none of which match up to the drive in the 286. I have tried a couple that were in the same ball park, but it only resulted in a hang in loading. While its conceivable that this drive is not original to the machine, or that it was never configured to it - I am thinking that wouldn't be the case as the case cover had all 5 screws in it, and the HD was solidly installed with all associated cables connected. (unless whoever did the install could never get it to work and that s how it ended up at the recyclers)

2. It has 1024k installed, which I am assuming are the small chips that run in 2 rows along the back of the motherboard. There are 36 of them (which does not divide evenly into 1024...) Will any 16 pin memory chip work in there? I have a couple extra Bocaram/AT's hanging around, can I use the chips out of them, or actually just plug them in? I am hesitant to just go plugging stuff as I don't want to do anything that will let the magic smoke out.

-Lance
 
Hi Lance,

Well done on the battery. If I ever get my PS/2 30-286 going, I'll see if I can screw up the courage to do this. It has a similar (dead) battery (-:

Strange about the drive not matching. Are you sure it's not one of the 47? You have all the specs, yes? For my IBM AT I found I had to goggle to the drive model to get them. They weren't written anywhere on the case.

Tez
 
The battery mod was really easy using the link that Chuck posted.

Much as you suggested there were no markings on the HD. I found in a few different places on the internet Head 6, Cyl 809, Sector 17, Precomp 128, LZ 512. There was nothing really even close. One was 6,820, but Precomp and LZ were both 820 (left field)

Tells me I have 47 options, I entered 47 (which was not in the list, stops at 46) and still get the error msg.

WHen its checking the disk it goes through a cycle of blinks 1 long, 4 to 5 short, 4 to 5 short, 1 long - repeat

-Lance
 
Darshevo said:
1. When using setup it only gives me options for 47 difference HD's none of which match up to the drive in the 286. I have tried a couple that were in the same ball park, but it only resulted in a hang in loading. While its conceivable that this drive is not original to the machine, or that it was never configured to it - I am thinking that wouldn't be the case as the case cover had all 5 screws in it, and the HD was solidly installed with all associated cables connected. (unless whoever did the install could never get it to work and that s how it ended up at the recyclers)
Click to expand...

Okay, what are you using for a controller? Some controllers record the drive parameters as an "invisible" sector on track 0 and read it up during initialization. In those cases, the drive type doesn't matter and is usually set to 1.
2. It has 1024k installed, which I am assuming are the small chips that run in 2 rows along the back of the motherboard. There are 36 of them (which does not divide evenly into 1024...) Will any 16 pin memory chip work in there? I have a couple extra Bocaram/AT's hanging around, can I use the chips out of them, or actually just plug them in? I am hesitant to just go plugging stuff as I don't want to do anything that will let the magic smoke out.
Click to expand...

36 chips = 4 rows of 9 (8 data bits + parity) = 256x1 DRAMs. (e.g. 41256). Some higher-speed 286s need 60 nsec DRAM, so that's something to watch out for.
 
A trick I used to find drive geometry is to plug it into a modern machine (one that can auto detect the drive type) and boom you have a very solid starting point. In most cases I find it works perfectly. Assuming, of course, that it is an IDE hard drive.

Isn't type 47 usually a custom configuration?
 
My HD Controller was a Data Tech (made in taiwan) couldn'd find an actual part number on it, serial 422C 07161. I swapped it out for a WD 1006-WA2. I may be hallucinating, but I think the WD actually had different drive options (altho still only 47) Sadly none of them corresponded to my drive.

Tomorrow when I get done with work I am going to try to swap out the mfm card for what I believe to be an ide card. I have done a lot of swapping tonight and am getting a little braver at experimentation. And as a plus there is a carriage inside for 2 3.5 sized HD's.

All in all its been a heck of a positive day. Got the clock fixed, got it to run off DOS in the A: drive, installed a bocaram board and now have a whopping 2866k ram (as compared to the 1024 I started with)

As always thanks to everyone for the ideas and info

-Lance
 
Darshevo said:
WHen its checking the disk it goes through a cycle of blinks 1 long, 4 to 5 short, 4 to 5 short, 1 long - repeat
Click to expand...
It seems that the Miniscribe 3650 is one of those drives that flashes the LED in a pattern if it detects a problem.

If you goto http://stason.org/TULARC/pc/hard-drives-hdd/miniscribe/M3650-42MB-5-25-HH-MFM-ST506.html, then scroll down a way, you'll see a section titled 'Error messages'.

I translate your "1 long, 4 to 5 short, 4 to 5 short, 1 long" to 1001. The 1001 maps to Code 9, which is "Unable to cover Track Zero sensor".
It suggests that your drive is faulty. Does the pattern flash when the data/control cables are disconnected?
 
Sometimes the "can't find track 0" is due to a sticking head positioner--or head-to-media stiction.

With the drive disconnected and out of the box, apply power. Do you hear it spin up? After it spins up, do you hear any other activity? If you still get the blinking, power the drive down and give it a good smart rap on the side of the HDA with the handle of a medium-to-large screwdriver. The object is to knock the heads loose as gently as possible. Repeat if no results.

Whatever you do, do not open the HDA (disk box) itself.
 
Good resource. It does indeed continue to flash its code when disconnected from the controller. I suppose not too hard to imagine as the drive is likely ~20 years old.

I guess that will teach me to RTFM as the Stason site is where I found the track/cyl info initially

Going to the electronics recycler again today, maybe I can find some more old iron to rob an hd out of, or possibly find a small IDE one in my parts bin

-Lance
 
Update on 286 HD debacle:

I smacked the MFM drive around as Chuck suggested. Lightly at first, then with a little more enthusiasm. It does make a noise on power up, but after that its silent.

I decided to go the sell out way and install a regular IDE drive. I have a small pile of JCC 800310 controllers that have (what I assume to be) an IDE and the smaller (forgive my ignorance of not knowing its exact name) plug for the floppy. When hooked up I am still confronted by the choose your HD out of the 47 listed (which now are light years away from the HD I am trying to install - largest is in the low 100mb range and the HD I have for this project is a 4.3gb) I have tried using 47 (which doesnt come up in the list at all, even tho its an option) 46 (which is represented by all 0's for cyl, head, etc) and 0 (which is unavailable option and it beeps to make sure I realize it). I think the first time I ever did an HD install was in a 486, which by then had a bios menu where you could manually input the cyl,head,etc setting. I can't for the life of me find a place in the start up to enter the info manually. Now when it boots it tells me I have a Hard Disk Controller Failure. Altho I have tried 3 of them, all with the same result, and in all cases the floppy works just fine.

I have one last plan of attack, I picked up an old 486 yesterday at the recyclers and I am going to see if I can do anything with the SCSI card in it and an old full height scsi drive I have on the shelf.

I fear I am missing something super easy/simple on the HD install, but lack of experience with these units is really kicking me in the keister.

-Lance
 
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Darshevo said:
I have tried using 47 (which doesnt come up in the list at all, even tho its an option)
Click to expand...

Do you mean it a selectable option with no parameters?

I am not sure about MFM, but with older IDE bioses type 47 was almost always a custom setting that allowed to put in your own parameters. Perhaps there is a way to do that with your BIOS using number 47?
 
If your SCSI card has a BIOS ROM on it, just set the SCSI ID on the drive to 0. It should be recognized. If you want to run OS/2 or other protected-mode software, you may need to find drivers for it.

But, in comparison to MFM drives, it should be pretty simple. FDISK and FORMAT as usual.
 
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