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IBM 5150 BIOS Upgrade: A tale of my 6 week mission

I

inaxeon

Experienced Member
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Jan 5, 2017
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Heya folks, just thought I’d share this -

I have an IBM5150 which had an older (5700671) BIOS in it and was quite keen to upgrade to the last (10/27/1982) revision so I could get 640K of RAM working, use a VGA card, and also try out XT-IDE.

But quickly found this physically wasn’t straight forward. Upon consulting the great 5150 gospel, I learn of the MCM68766 EPROM, but as it mentions, finding hardware to program it not is so easy, but I purchased some anyway.

I have three EPROM programmers:

* MCUmall GQ-4X: Bupkis. No support for it.
* Un-branded eBay special: Also bupkis. Not even close.
* Xeltek SuperPro 610P: Supported (Apparently)

So I put one in the SuperPro, loaded up the 10/27/1982 image, press go, and it errors out after programming the first byte. Gah!!!!

Turns out all of the samples I purchased have the same problem, the SuperPro successfully programs the first byte then bombs out.

Somewhat frustrated at this point, suspecting a bug in the SuperPro’s algorithm (Not the first I have observed) I then set out to build my OWN stinkin’ programmer.

Quite a lot of evenings later, I produced this design, in the form of an Arduino Mega shield, a month later my board (made by SeeedStudio PCB) arrived –

https://s3.amazonaws.com/techmattmillman/files/embedded_images/IMG_0244.JPG

And it successfully programmed a MCM68766! So I’m now in business. The cost of building this was barely more than GBP £30 (less the cost of an Arduino Mega) – quite lot cheaper than forking out for another professional grade programmer.

Old and new:
https://s3.amazonaws.com/techmattmillman/files/embedded_images/IMG_0224.JPG

New BIOS installed:
https://s3.amazonaws.com/techmattmillman/files/embedded_images/IMG_0232.JPG

Anyway I do appreciate that this may be somewhat of an overkill approach i.e. most would build a socket adapter and a newer EPROM but if anyone else wants to attempt something like this, I will be sharing all of the info needed.
 
Well, I'm somewhat surprised that so many EPROM programmers advertised as supporting the chip can't program it successfully.
But nice going on making your own programmer, and doing a successful ROM :)

Which makes me wonder: What about the BASIC ROMs? Were they updated during the lifetime of the 5150 (or 5160/5170) as well, and if so, are you planning to upgrade those as well?
 
Scali said:
Well, I'm somewhat surprised that so many EPROM programmers advertised as supporting the chip can't program it successfully.
But nice going on making your own programmer, and doing a successful ROM :)

Which makes me wonder: What about the BASIC ROMs? Were they updated during the lifetime of the 5150 (or 5160/5170) as well, and if so, are you planning to upgrade those as well?
Click to expand...

Good question. I have not made use of the BASIC ROMs yet. I think there were a couple of revisions but it's unlikely I'll be touching mine.

I suppose a more interesting case would be putting other stuff in there, i.e. floppy BIOS...
 
One of the reasons to hang onto old programmers...

I have an old parallel-port programmer (EZ/EP that did both the '765 and '766 with no problems. Needless to mention, it's MS-DOS only.

I suppose I should try that on my old Xeltek Superpro/L; heck, maybe my old Sunshine PC programmer will do it.

Nowadays, it seems everything is flash. JTAG is good enough.

Can't do 2704/2708/1702, but I don't have much that depends on those dinosaurs.
 
Chuck(G) said:
One of the reasons to hang onto old programmers...

I have an old parallel-port programmer (EZ/EP that did both the '765 and '766 with no problems. Needless to mention, it's MS-DOS only.

I suppose I should try that on my old Xeltek Superpro/L; heck, maybe my old Sunshine PC programmer will do it.

Nowadays, it seems everything is flash. JTAG is good enough.

Can't do 2704/2708/1702, but I don't have much that depends on those dinosaurs.
Click to expand...

The programmer I designed and show in that picture does do 2704/2708 - figured I'd knock those off while I was at it. All it needed was a -5V switching converter, and 4PDT switch to swap the '766's extra address lines with the three extra power rails on the 270x
 
Hi, did you put up your design of the eprommer shield somewhere? Thanks.
 
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