Early IBM 5150

[modem7]

Early IBM 5150 on eBay at item 230256892551 (not mine).

* 2 screw case (instead of standard 4 screws)
* Lack of "B in circle" on rear

Serial number of 0239462 predates serial number of my early 5150 - black power supply and 16/64K motherboard. Hopefully those components haven't been upgraded.

[billdeg]

I bid and won it just now, thanks for the tip...the pictures were a little fuzzy, but after study I don't think that they were altered and this is a real "A" model.

Does your 5150 "A" have the same placement and type of serial number sticker, and also have the cassette/keyboard labels?

The 5150 "A" that I just restored for the M.A.R.C.H. computer museum has no cassette or keyboard stickers, and the S/N sticker is different. The "Hi POT and "OK 27" are closer together. It is S/N 192562. and it was an internal IBMer's system. Maybe it was a very early production version, even for an "A" - What is the lowest known 5150 serial number?

It's too late now, I bought it....I have a 16K/64K motherboard, RAM, etc. I really just want the A chassis and hopefully black power supply. If the motherboard and RAM works it'd be a bonus.

Bill

[modem7]

Hopefully the motherboard (if original) still has its early revision BIOS. If by very lucky chance it is the first revision, please send me a file copy so I can update my collection at http://members.dodo.com.au/~slappanel555/bios.htm

My 'early' 5150 is s/n 0287794 and was made is the US. Only one owner before me and so I know that there were no repairs/changes.

Does your 5150 "A" have the same placement and type of serial number sticker, and also have the cassette/keyboard labels?
Yes and yes.

[billdeg]

Here are pics of my computer clubs IBM I just finished restoring...includes screen shots that will tell you BIOS version:
http://www.vintagecomputer.net/ibm/5150/5150_A/

and the restoration notes:
http://www.vintagecomputer.net/browse_thread.cfm?id=161

[mbbrutman]

So, is it the first revision BIOS? (Did you do the Debug trick to look at the date in ROM?) The version of Cassette BASIC is certainly old enough ..


Mike

[billdeg]

what is the debug trick? I will check. I bet it is. How does one copy the BIOS in this particular case with this particular machine- I am happy to send to you.
Bill

[mbbrutman]

C:\>debug
-d ffff:0
FFFF:0000 EA 5B E0 00 F0 30 34 2F-30 32 2F 30 32 00 FC 86 .[...04/02/02...


Your date code will obviously be much earlier .. I'm guessing about 21 years earlier.


Mike

[billdeg]

brace yourself....

10/18/81

!!

[mbbrutman]

Rats .. 2nd revision of the BIOS.

Welcome to the club though ...

[billdeg]

Just for clarification's sake - that's the ROM of the computer I am storing for the MARCH computer museum.

I posted in the PC section of this forum, but it's relevant here too..the 5150 "A" from the auction that started *this* post ROM is dated 10/27/82. That makes it either a very late model A or the BIOS was upgraded in order to use the Plus Hardcard 20 found installed in the unit (and not working).

Here is the thread from my blog about the final restoration of the computer from this auction
http://vintagecomputer.net/browse_thread.cfm?id=165
...with some pics.

[mbbrutman]

And rats, I misread the date .. that is the 3rd revision, not 2nd revision.

[Trixter]

brace yourself....

10/18/81

!!

Would you be willing to dump this for a friend? He claims the ROM dumps on the web that people usually reference aren't dumped correctly. If you're willing (it only takes a floppy disk and DEBUG.COM, I have instructions), let me know and I'll forward his email to you (PM me your email if you can help).

[mikey99]

Checked my 16/64K MB last night, it showed 10/19/81.

Oddly enough this one is in a case with the "B" stamp on the back.

[MikeS]

Wow, that was a short run... ;-)

Mine have 1983 date codes, but I could probably dump 'em if anybody's looking. What size are they BTW?

m

[billdeg]

Just tell me how and I'll post to my website for all. I have them both up on the bench, and anot e coming in tomorrow.
bd

[Trixter]

Awesome! The guy in question is one of the MESS developers.

Follow the instructions at http://mess.toseciso.org/dumping:dump_bios_using_debug
and post the MYF000.BIN and MYF800.BIN files produced.
also, if you can, crack open the case and note down the numbers/markings/labels on the five chips at u29, u30, u31, u32, u33. If there is a chip in the socket at u28, note down the numbers on it too.

For instance, on the third rev 5150 bios, the chip at u33 has silkscreened on it:
MK36C35N-4
1501476
Z A
(C)IBM CORP
1981,1983
D DALLAS
8347

This information will help the MESS developers to get their PC emulator more exact.