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



inaxeon
February 26th, 2017, 11:44 PM
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.

Scali
February 27th, 2017, 12:22 AM
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?

inaxeon
February 27th, 2017, 12:31 AM
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?

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...

Chuck(G)
February 27th, 2017, 12:43 AM
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.

inaxeon
February 27th, 2017, 12:50 AM
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.

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

Plasma
February 27th, 2017, 06:35 AM
Alternatively, you can use an adapter (http://store.go4retro.com/2364-adapter/) with a 27xxx EPROM.

inaxeon
February 27th, 2017, 06:51 AM
Alternatively, you can use an adapter (http://store.go4retro.com/2364-adapter/) with a 27xxx EPROM.

As per my original posting, I was aware of that option -

But EPROM projects are difficult to resist...

glitch
February 27th, 2017, 06:54 AM
But EPROM projects are difficult to resist...

Heh, very true. I need to actually finish some of mine! Good work :)

ch1ller
September 26th, 2018, 09:14 AM
Hi, did you put up your design of the eprommer shield somewhere? Thanks.