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IBM PC 5150 Rev.A (Early S/N : 0101876)

Hey guys. I am still working on my 5150 early model (would it be a Rev B if its a 16KB-64KB board with the Oct 1981 bios as opposed to the April 1981 bios?). Anyway I had a general question. Been doing alot of repair work on my 5150's and 5160's in the past few weeks. I have one board that came out of a 5150 that I am not sure is authentic. How can you tell if a board is IBM or Clone?
Rev A is the 16/64 motherboard and Rev B is the 64/256 motherboard. ROM version does not affect this (most rev A owners upgraded their BIOS anyways).

A true IBM board will have a silkscreened part number on the board that can be researched/verified. If in doubt, you can start a thread with a pic and let the experts in this forum weigh in.
 
If the serial number was close to what I was looking for, I could have bought it quickly, but as soon as I checked the number, I gave up on the instant ball.
This is because you already have a motherboard with a lower number than that serial number.
 
If anyone is wondering, the Rev A that just came up on eBay is serial 131599 per seller. Item 285016679579
 
someone finally has to make web site which contains registration of serial numbers of early IBM PC's and its parts. I have two revision A PC's and also I am big fan of low serial numbers and specific parts and anomalies of these early models.
 
How early does it have to be to be considered early? Anything in 1981?

I’ve got just one 16-64k board, that I picked up recently. It seems like it’s probably from no earlier than the 13th week of 1982. But it does have the middle BIOS from 10/19/81.

I don’t care too much about how early it is, other than having an example of each major type of board or complete system, to help with recreating similar setups for testing things.
 
I only encountered 4 motherboards with IBM PC 5150 Rev.0 (04/24/81), but two of them had BIOS and motherboards that were completely broken and could not be repaired.
(The two bad BIOSes were discarded a long time ago, and the two main boards were also requested to be repaired by someone they knew, but they were determined to be impossible, so they actually requested to be discarded.)
Fortunately, the 2 units have been repaired and are still being used for inspection purposes. We check the operation by supplying electricity.
 
How early does it have to be to be considered early? Anything in 1981?

I’ve got just one 16-64k board, that I picked up recently. It seems like it’s probably from no earlier than the 13th week of 1982. But it does have the middle BIOS from 10/19/81.

I don’t care too much about how early it is, other than having an example of each major type of board or complete system, to help with recreating similar setups for testing things.
What constitutes “early” is a bit subjective and really depends on the collector. Many will consider PC1 (aka Rev A) as all early, whereas I tend to cut it off at the first 100k produced…anything after that doesn’t have a lot of the “interesting” differences that show how IBM went from small scale production to ramp-up with bulk part suppliers (and revisions of boards as mods were applied). Remember, back then, success was certainly not a given, and many experts thought it would fail and we’d all be on Commodores for years to come. :)

Of course, a lot of the early systems were upgraded over the years with BIOS, power supply, etc, so there will usually be a mix of stuff in most systems. Finding a very early one with all original is becoming rarer but a lot of fun when found.
 
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someone finally has to make web site which contains registration of serial numbers of early IBM PC's and its parts. I have two revision A PC's and also I am big fan of low serial numbers and specific parts and anomalies of these early models.
I completely agree. I know several in this forum are tracking these things but it would be neat to have an online “registry” of sorts. A lot of the early systems were upgraded over the years so it would be hard to track some things, but certainly motherboard and other things like speaker would be pretty accurate.
 
Is there any other standard place where the serial number was printed other than the sticker on back of the case? I have a Rev1 5150, however the sticker on the back has been lost to time. I know this one isn't particularly early (chips date Jan 82 and MB P/N 1840401) but I suppose I'm curious where it falls in the line.

edit: or am I a dummy and that silkscreened number on the MB is the S/N?
 

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I believe the only place the serial number is located is on the back label. Examining the front inside of the top cover can sometimes show a date stamp. I think your 5150 is a fairly early model as the floppy controller has the earlier 3 metal capped chips (4217813x2 and the large IBM5564252).
Even missing the S/N it still looks like a nice system.
 
With the sunken nut black power supply, I would guess a serial number range around 180000+, but that’s just a wild guess. But probably no earlier than that. Unfortunately the only place for the serial number was the rear sticker.
 
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One wonders what the 5150 equivalent of this would go for.


It was reportedly found in a footlocker in an attic that was being cleared out.
 
One wonders what the 5150 equivalent of this would go for.


It was reportedly found in a footlocker in an attic that was being cleared out.
As are a lot of 5150s as well.
 
IBM PC 5150 (Rev.A with S/N : 0109329) is listed on eBay.



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So, this exact system just popped back on eBay for considerably more than it sold for just 2 weeks ago. Someone’s just trying to make a quick buck.
 
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