Can someone help me date my 5150?

[MacGyverr]

It has an upgraded 10-27-83 bios and I replaced one of the onboard 6114 RAM chips that had a parity error with a newer one, but all other chips are original.
I remember reading that the serial number doesn't really mean anything, but it translates to 0154998.

There is no date anywhere inside.

It came with:
IBM 1504910 CGA
IBM 1504900 MDA/parallel
IBM 1503800 360k 5.25 floppy
Jameco JE1078 320 RAM-RTC-IO
HD Controller WD1002A-WX1 (VER.1)
IBM 5.25 Diskette Drive Adapter
IBM 64-256KB Memory Expansion Option
WESTERN DIGITAL-WD12
Seagate ST 225
TEAC 720k 3.5 floppy
Extender and Receiver cards

I purchased a Video 7 Vega VGA and a DB62 cable for the 5161

I have all the cards cards set correctly but I think my newer VGA card screws up the memory count, it shows as having 768KB and was throwing a higher 201 error in the AXXX range before it started throwing other ones.

I had it working with all 640KB (64+256+320), and even got the WD12 working in the 5161 , and when I got the ST225 working it all started going downhill. Now it doesn't boot even to Basic with just the 64KB onboard RAM, and only turns on to a Parity Error and no post error.
I'm hoping it's the other Caps and when I replace them and remove and deox the chips that it will work ok again.

I'm hoping that the old caps are creating unstable power and that is leading to the issues. I also purchased a GBS8200 so I could use the original CGA card and eliminate the VGA card (I can't find a CGA monitor so I tried this newer VGA card first).
Any tips or things I should avoid doing, I plan on removing the chips and cleaning and de-oxing the sockets and board with alcohol and anti-static brushes. Replacing the tantalum capacitors and adjusting the voltages on the power supply to exactly 12 and 5 with all the cards in. I already replaced 2 caps on the 5161 to get it to power up, but only cut the leg of the -12v cap on the 5150 when it was shorted, I haven't replaced it yet.

I don't know where to start on repairing the floppy drive, it prevents the power supply from powering up when plugged in.

I think it lived in a barn for the last 36 years, I purchased it cheap from a guy that had it in a barn because I thought it would be toast inside and I could make use of the case. It wasn't until I got it home and opened them up that I realized they were complete and untouched for decades, now I can't bring myself to do anything but restore them. Please help with any insight you can offer.

 

[DaCiRo]

The Bar Code definitively reads 0154998, probably not traceable to any useful info that can reveal a date.
One of the pictures, the one with the empty case has a 'ComputerLand' sticker, looks like there is a date printed on topI , maybe that can give you a sense to date the PC. Also I found this.

COMPUTERLAND/TYSONS CORNER, 8411 Old Courthouse Road at Route 123. 893-0424. COMPUTERLAND/ANNAPOLIS, West Street and Route 2, Annapolis. 301/266-6277. COMPUTELAND, 16065 Frederick Road, Rockville. 301/948-7676. COMPUTERS, PLUS, 6120 Franconia Road, Alexandria. 971-1996.

 

[bburley]

The last time I had one of those floppy's that did that, it was the 12 Volt power line that was shorted. Following the 12V line, it went through an inductor (possibly L4) and when that was unsoldered, I found which side of it was shorted and then started lifting one lead of the tantalum capacitors on that line and managed to find the shorted one.

 

[Chuck(G)]

How to date your 5150? A nice bouquet of flowers is a good start...

 

[modem7]

I don't know where to start on repairing the floppy drive, it prevents the power supply from powering up when plugged in.

The last time I had one of those floppy's that did that, it was the 12 Volt power line that was shorted. Following the 12V line, it went through an inductor (possibly L4) and when that was unsoldered, I found which side of it was shorted and then started lifting one lead of the tantalum capacitors on that line and managed to find the shorted one.

See the 'Short-circuit capacitors' section of [here]. That identifies the two capacitors that people report as 'found short-circuit'.

 

[Zare]

Radioisotope dating is another method if you don't mind the hundred thousand years +- precision

 

[daver2]

The date codes on the ICs are mainly 1982, with the odd 1981 devices.

1982 to 1983 would be a ballpark date for the motherboard (if that is of any help to you).

The ICs wouldn't have languished around for long at the time these machines were made in bulk.

Dave

 

[MacGyverr]

After the 5161 cap repairs and 4116 chip replacement and clipping the leg on one of the -12v tantalums it was working mostly ok. I could even use the WD12 in the 5161 (albeit with my Gotek and various bootable images) until I configured the ST225 with the SSTOR program and set what I'm guessing were the internal HD controller bios settings to the correct settings for a 225, then it slowly started going crazy. First it would give Disk Failure errors on my Gotek, then not read any images, then 509C 201 errors, which doesn't seem to be a real error code, or at least not for when the Map was made for the 256KB card. And then it would only boot into Basic, and now it won't even do that with just the VGA card alone and only the on-board RAM. Now it posts, throws no errors, and jumps to parity error.
Should I just start replacing tantalum capacitors until they are all new? I purchased a few and replaced the bad ones on the 5161 board, they are 10uF 16v but the replacements seem physically smaller than the originals. I guess my real question is are all 40 year old tantalum capacitors bad?
Here are some more pictures of all the cards. I'm hoping to remove the ebay VGA card and use an adapter on the CGA until I can find a 5151 and 5153 in my area (Olympia WA) once I can get it working again.

Just to confirm, there is no way a 40 year old virus can make any permanent setting changes to just the motherboard, right? Maybe the floppy images on the Gotek and maybe some settings in the WD controller, but the 5150 BIOS and BASIC BIOS are permanent and nothing can alter them, right? It just really looks like when the ST225 was booted, it went crazy.

 

[rmay635703]

When did 64k boards stop manufacture?

 

[Chuck(G)]

The latest IC date on the board is a good approximation. Demand was high early on, so I suspect the TTL jellybeans didn't get too moldy while they sat in IBM's parts crib.

 

[modem7]

Now it doesn't boot even to Basic with just the 64KB onboard RAM, and only turns on to a Parity Error and no post error.

You are seeing something on-screen, which in my opinion, is a better situation than nothing on-screen.

It sounds like you are aware of [this] requirement.

The motherboard photo in post #1 shows that the RAM related settings on the SW1/SW2 switch banks are good for your configuration. (16KB-64KB motherboard, 10/27/82 BIOS, all motherboard RAM banks populated, no RAM cards.)

Are you in a position to use Ruud's Diagnostic ROM - see [here].

 

[modem7]

I had it working with all 640KB (64+256+320), and even got the WD12 working in the 5161 , and when I got the ST225 working it all started going downhill.

Sometimes, it is power-applied that pushes aged/damaged components to fail, and sometimes it can take a while for that to happen. I remember that many years ago, I acquired a used IBM 51xx power supply. It ran fine for about 30 minutes or so, then failed. When I opened it up, it was obvious that the supply had been in damp conditions for a long time. The moisture-affected component that failed is pictured in the 'Moisture affected diodes - Example #1' link at [here].

 

[MacGyverr]

Do you have a place where I can just buy a drop in version of Rudd's Diagnostics?
The hard drives were in the 5161, but the 5150 did have all 5 slots going.
I have removed all the tantalum caps and ordered new ones, I have removed all socketed chips and cleaned and de-oxed all the sockets and the board. (I didn't remove the 8088 though, I don't have that chip extractor and just figured it would crack in half if I tried using a flat head screwdriver and muscle it out,)
As soon as I install the new caps and reinstall the chips we'll see how it goes, I'd love to have a copy of Rudd's bios to try instead, but I have no eproms or a programmer to make one and all the listed sources seem to be out of stock.
It would be great if I could go on ebay and just buy one. I can find this one, but not Rudd's. https://www.ebay.com/itm/334170590723

 

[modem7]

After the 5161 cap ...

This post has appeared.

Just to confirm, there is no way a 40 year old virus can make any permanent setting changes to just the motherboard, right?

Not on a motherboard of this vintage.

I guess my real question is are all 40 year old tantalum capacitors bad?

No. I have 5150/5160 motherboards that have none of the tantalum capacitors replaced. Most of mine have one or two replaced.

then 509C 201 errors, which doesn't seem to be a real error code, or at least not for when the Map was made for the 256KB card.

64 KB on the motherboard, plus a 256 KB RAM card = 320 KB fitted.
Per [here], 509C equates to 4 bits in error somewhere in the address range of 320K to 324K.
So, for some reason, the POST tested past the 320K mark (i.e. tested RAM that did not exist at the time).

There are only four reasons that I know of for the 5150's BIOS testing beyond what is fitted:
- Certain cases of incorrect SW1/SW2 settings.
- The problem described at [here], not applicable in this case.
- Hardware: Certain cases of faulty/dirty RAM related switches in SW1/SW2.
- Hardware: Circuitry that reads the switch settings are not reading one or more switches correctly.

I suspect incorrect switch settings.

Re the two hardware causes. If one can get into Cassette BASIC, then the code at [here] tests the switches and reading circuitry. If the output of Ruud's Diagnostic ROM (RDR) is viewable via a monitor, RDR shows what switches are being read as what.

It just really looks like when the ST225 was booted, it went crazy.

Possibly just a timing coincidence.

Something else to consider is a power supply overload. A 63W power rating is not much, and some old power supplies may have deteriorated in a way where they struggle at the higher power levels.

Take the configuration back to a 'minimum diagnostic configuration', i.e. only power supply, motherboard, and VGA card.
If that configuration behaves as expected, one by one, add things until failure.
If that configuration does not behave as expected, diagnose that.
Then add more things, etc.

Are you in a position to use Ruud's Diagnostic ROM - see [here].

Not with a VGA card, but maybe you have the ability to monitor the diagnostics's output via RS-232 serial.

Now it posts, throws no errors, and jumps to parity error.

1. In the minimum diagnostic configuration that I wrote of earlier ?
2. There was no 201 error before the screen cleared and the PARITY CHECK error appeared ?
3. PARITY CHECK 1, or PARITY CHECK 2 ?

Note that for the IBM 5150, incorrect switch settings are one of the causes of a PARITY CHECK error at power-on time.

 

[MacGyverr]

With all the 640K RAM (64KB onboard, 256KB on the IBM expansion card (starting at 64KB), then 320KB more from the Jameco multi-card starting at 320KB) it worked for a bit with no 201 errors other than high AXXX ones, but now with just the VGA card and 64KB and nothing else and set for no floppy, it doesn't boot into BASIC. It was running various floppy images off my FlashFloppy Gotek and with the 5161 connected I was running programs off the WD12, and when I set the metrics for the ST225 in SpeedStor, it went downhill from there. Now just the parity error (after no post errors), sorry I don't remember what the parity number was. Hopefully it was just bad connections in the sockets and a cap somewhere, we'll see after the new caps get installed.
Should I try to adjust the power supply to exactly 5 and 12, it was a little low on the 12 side (like 11) and a little high on the 5 side (like 5.2) before. I just hope it comes back to what it was before.
Just to confirm, de-ox is not conductive? It kind of gets all over the place.

 

[MacGyverr]

64 KB on the motherboard, plus a 256 KB RAM card = 320 KB fitted.
Per [here], 509C equates to 4 bits in error somewhere in the address range of 320K to 324K.
So, for some reason, the POST tested past the 320K mark (i.e. tested RAM that did not exist at the time).

There are only four reasons that I know of for the 5150's BIOS testing beyond what is fitted:
- Certain cases of incorrect SW1/SW2 settings.
- The problem described at [here], not applicable in this case.
- Hardware: Certain cases of faulty/dirty RAM related switches in SW1/SW2.
- Hardware: Circuitry that reads the switch settings are not reading one or more switches correctly.

I suspect incorrect switch settings.

At the time it was throwing the AXXX error it had both RAM cards in and was jumped to 640KB, when it started to go downhill I removed all cards but the VGA and rejumpered it to no floppy and set it to 64KB.
I first tried to see if the factory 256KB card was ok and removed the Jameco 320KB and reset the DIPs to 320KB, and the error was 509C, but this Map in the picture was confusing as my error ended in 9C, and not what was listed, but I'm guessing that it means "error closest to these numbers before reaching it". Does a 9C mean Bank 1 chip 3? Or because my error isn't in that list it's nonsensical and the result of a primary issue like voltage?

Right now I'm just hoping to see it work on just the 64KB and VGA card, the 4164 RAM in the expansion cards is easier to find.
If my CGA to VGA cable ever gets here I hope to use it with a GBS8200 and try using just the factory CGA card. I keep thinking the weird AXXX RAM error code I was getting when everything was working correctly is related to the VGA card or/and its BIOS.

Thank you for the floppy link, I remember seeing it before but couldn't find it again. I have ordered some 4.7uf 25v caps and will start fix it as soon as the MB works.

 

[modem7]

... and the error was 509C, but this Map in the picture was confusing as my error ended in 9C, and not what was listed, but I'm guessing that it means "error closest to these numbers before reaching it". Does a 9C mean Bank 1 chip 3?

No.

See the 'POST test of conventional memory' section of [here]. The first two characters point to an address block/range. The next two characters point the bit/s in error. A related diagram is the one at [here].

Address block indicator

An address block indicator of '50' equates to address range of 320KB to 324KB-1. So, the failure address is somewhere in that range/block. In most cases, it is the first address of the range/block.

At the time, you had 64K on the motherboard and an 'IBM 64/256KB Memory Expansion Option' card in (configured to start its RAM at address 64 KB).
Therefore:

Motherboard bank 0 (16K sized) = addresses 0KB to 16KB-1
Motherboard bank 1(16K sized) = addresses 16KB to 32KB-1
Motherboard bank 2(16K sized) = addresses 32KB to 48KB-1
Motherboard bank 3(16K sized) = addresses 48KB to 64KB-1
IBM 64/256KB MEO bank 0 (64K sized) = addresses 48KB to 128KB-1
IBM 64/256KB MEO bank 1 (64K sized) = addresses 128KB to 192KB-1
IBM 64/256KB MEO bank 2 (64K sized) = addresses 192KB to 259KB-1
IBM 64/256KB MEO bank 3 (64K sized) = addresses 256KB to 320KB-1

'50' equates to address range of 320KB to 324KB-1. So, for some reason (see post #14), the POST had gone on to test RAM starting at address 320K, and understandably, failed, because there was no RAM at that address.

Bit indicator

A bit indicator of '9C' (9C hex = 10011100 binary) equates to bits 7, 4, 3, and 2, in error.

We know that the POST was testing RAM that did not exist, and so multiple bits reported as a problem is quite understandable. No, the IBM POST will not show all bits in error. There is a technical reason.

Summary

No point looking for faulty RAM chips in this scenario. The problem in this scenario is that for some reason (see post #14), the POST had gone on to test RAM that did not exist.

 

[modem7]

If my CGA to VGA cable ever gets here I hope to use it with a GBS8200 and try using just the factory CGA card.

Aware of the information at [here], in particular, the comments regarding the GBS8200 ?

 

[modem7]

Should I try to adjust the power supply to exactly 5 and 12, it was a little low on the 12 side (like 11) and a little high on the 5 side (like 5.2) before.

See [here] for what IBM considers acceptable.

 

[modem7]

I strongly recommend (for now and later) that you go down a parallel path of getting a 'Ruuds Diagnostic ROM' (RDR) and if applicable, a suitable ROM adapter.
For example, because you cannot get into Cassette BASIC, RDR will inform us if there is a problem related to the SW1/SW2 switch banks (switches in the banks, or the circuity that reads them).

BTW. You can use a multimeter in resistance mode to check the actual switches. With a switch in the on position, the resistance should be 0 ohms or perhaps 0.1 ohms. When you turn the switch to off, the resistance reading will go to something very high.