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Old IBM Model m with a unique controller help

Posted: 04 May 2019, 19:37
by Fkazim
So today I opened one of my really old IBM Model M's and it has a controller unlike any I have seems before on my other Model M's please help me identify please see image.

It seems to have a metallic thing on the main chip with a sticker over it should I pull the sticker off and take a picture of what's below?

Re: Old IBM Model m with a unique controller help

Posted: 04 May 2019, 21:02
by Polecat
Fkazim wrote:
04 May 2019, 19:37
So today I opened one of my really old IBM Model M's and it has a controller unlike any I have seems before on my other Model M's please help me identify please see image.

It seems to have a metallic thing on the main chip with a sticker over it should I pull the sticker off and take a picture of what's below?
The sticker is there to prevent the contents of the controller's internal EPROM from being erased (by exposure to UV light). If you remove the sticker you risk losing the contents of the EPROM. Later/cheaper/mass produced controllers used one-time PROM instead of EPROM (Erasable Programmable Read Only Memory) so those aren't reusable and don't have a window.

Re: Old IBM Model m with a unique controller help

Posted: 04 May 2019, 21:21
by Fkazim
Thanks for letting me know I will be sure not to ever remove the sticker.

But when you say Later/cheaper/mass produced controllers would that mean that the Model M keyboard this controller came out of is a pre production/prototype model?

Thanks anyway for letting me know what the sticker was there for and what the chip was :D

Re: Old IBM Model m with a unique controller help

Posted: 04 May 2019, 21:40
by Polecat
Fkazim wrote:
04 May 2019, 21:21
Thanks for letting me know I will be sure not to ever remove the sticker.

But when you say Later/cheaper/mass produced controllers would that mean that the Model M keyboard this controller came out of is a pre production/prototype model?

Thanks anyway for letting me know what the sticker was there for and what the chip was :D
Sorry, I'm not familiar with the Model M keyboards, but someone here will know if that's an unusual controller.

Re: Old IBM Model m with a unique controller help

Posted: 04 May 2019, 21:45
by Fkazim
Ok well I really appreciate the info you gave me anyway Thanks.

Re: Old IBM Model m with a unique controller help

Posted: 04 May 2019, 21:59
by zrrion
When was the board it came from made?

Re: Old IBM Model m with a unique controller help

Posted: 04 May 2019, 22:18
by Fkazim
It was made in 1986 and was made in the United Kingdom.

And it is even heavier than my bolt modded square label with lock lights IBM Model M made in 1987.

Does that help identify weather it is a pre production/prototype model?

Re: Old IBM Model m with a unique controller help

Posted: 07 May 2019, 15:56
by Fkazim
Anyone with any other ideas what I got on my hands please helps Thanks.

Re: Old IBM Model m with a unique controller help

Posted: 07 May 2019, 17:29
by JP!
Well you don't even have a pic of the label or list the part number in this thread but it sounds like you have an early production model and not a prototype. The controller looks fairly standard to me. The earliest production Model M's were made in 1985 and prototypes I believe date to later in 1984.

Re: Old IBM Model m with a unique controller help

Posted: 07 May 2019, 18:10
by Fkazim
part number is 1389969 and the keyboard has a square silver metal IBM badge with no lock lights hope that helps.

Re: Old IBM Model m with a unique controller help

Posted: 07 May 2019, 18:38
by JP!
I believe your board is essentially the ISO / UK version of the IBM 1386303 which is pretty much the first of the Model M keyboard's which were not intended for PC's.

Also see:
viewtopic.php?f=2&t=16967

Re: Old IBM Model m with a unique controller help

Posted: 07 May 2019, 19:12
by Fkazim
Wow well not a prototype but one of first ISO UK layout Model M's very cool it's really heavy too :D

Thanks for identifying it really appreciate it.

Re: Old IBM Model m with a unique controller help

Posted: 07 May 2019, 22:46
by Wazrach
Fkazim wrote:
07 May 2019, 19:12
Wow well not a prototype but one of first ISO UK layout Model M's very cool it's really heavy too :D

Thanks for identifying it really appreciate it.
How heavy? Are you able to weigh it? :3

Re: Old IBM Model m with a unique controller help

Posted: 07 May 2019, 23:18
by Chyros
The very first Ms had a repurposed, depopulated terminal controller from 1984 and the famous Mandolin crystal; this one lacks both.Still, a 1986 M is always a great find, so congrats! :D

Re: Old IBM Model m with a unique controller help

Posted: 08 May 2019, 01:48
by Fkazim
Thanks Chyros

Re: Old IBM Model m with a unique controller help

Posted: 08 May 2019, 01:50
by Fkazim
All restored now it's in amazing condition overall part number is
1389969

Re: Old IBM Model m with a unique controller help

Posted: 08 May 2019, 11:39
by Fkazim
Sorry Wazrach about your question before the weight is 2.29kg

Re: Old IBM Model m with a unique controller help

Posted: 08 May 2019, 11:50
by Wazrach
Fkazim wrote:
08 May 2019, 11:39
Sorry Wazrach about your question before its 2.29kg
No problem, thanks for letting me know!

I have a square badge Model M with lock LEDs on the way, a UK model from March 1987. I feel almost guilty for nabbing it for £70 shipped!

Re: Old IBM Model m with a unique controller help

Posted: 08 May 2019, 11:57
by Fkazim
Wow very good deal I got a pretty good deal too on my IBM Model M silver label 1987 keyboard with lock lights. I paid £77 for mine you never know with these things as I got my first generation IBM Model M XT with no locklight 1986 keyboard for just £55 that was a great day :D

Re: Old IBM Model m with a unique controller help

Posted: 09 May 2019, 20:39
by Wazrach

Re: Old IBM Model m with a unique controller help

Posted: 09 May 2019, 21:15
by Fkazim
Sounds great and it is in fantastic condition good find :D

Re: Old IBM Model m with a unique controller help

Posted: 09 May 2019, 21:17
by Fkazim
Also if you are interested here is the full restoration log of my IBM Model M silver label 1987 keyboard hope you like it.

viewtopic.php?f=2&t=21739

Re: Old IBM Model m with a unique controller help

Posted: 10 May 2019, 15:13
by Howard81
This controller is pretty common in 1986 and early 1987 Greenock Model M keyboards, moreso in the "enhanced" keyboard that came with late models of XT.

Re: Old IBM Model m with a unique controller help

Posted: 10 May 2019, 16:16
by Fkazim
Thanks for letting me know I'm really happy overall with this keyboard which I got for a great price.