Genuine Model M 1390131?

[duality]

Hello,

I'm new to Deskthority.
I've just recently discovered the world of vintage, clicky keyboards and thought I'd start a collection with a Model M.
Anyway, I bought this one from ebay recently and was wondering if its a legitimate build or if someone perhaps switched the case or something.

From what I understood, these older models were supposed to have a thicker, shiny (gold-like color) backplate inside. But when I open mine up it seems to be a gray color that I see on the newer model Ms. I'm no expert so I was wondering if anyone can confirm this for me?

Front

Spoiler:

Back

Spoiler:

Backplate

Spoiler:

Thanks a bunch and looking forward to being on Deskthority!

[Inxie]

I thought the goldish backplate was only for the Model F's? My F has golden rainbow colored, and my Model M is grey.

[duality]

I've seen lots of pictures like this one:
https://clickykeyboards.com/product/198 ... 30-jul-86/

I could be wrong, but I thought the older ones had a colored hue about them...

[Weezer]

So there wasn't ever a clean break when IBM started introducing cost cutting parts on their keyboards. You have a late 1390131 that was made after they'd already started making the PS/2 1391401 model with the gray oval badge. What probably happened is they finished a preexisting order for an AT keyboard using the current stock of parts for the PS/2 models. I don't think this is fake or swapped.

[kmnov2017]

It's definitely genuine. There are known anomalies with parts. Not all 87 models had the "golden" plates. Also I've seen black cables on models as late as 1990.

[depletedvespene]

It's definitely genuine. There are known anomalies with parts. Not all 87 models had the "golden" plates. Also I've seen black cables on models as late as 1990.

It's not just "anomalies", but also using parts according to a determined part number. I have a couple NOS keyboards made by Lexmark in 1996, well after SDL plugs "should" have been discontinued, that DO have SDL plugs... and this was very probably because Lexmark received an order for a batch of P/N 1391506 keyboards (and that was quite probably because there was no analogous to the P/N 82G2384), so they did them according to that spec.

@duality : you got yourself a very nice keyboard. Enjoy it for the decades to come!

[fohat]

but I thought the older ones had a colored hue about them...

"older" is probably 1986 for sure and maybe 1987

Great keyboard, I would say that is the best possible Model M.

[Weezer]

but I thought the older ones had a colored hue about them...

"older" is probably 1986 for sure and maybe 1987

Great keyboard, I would say that is the best possible Model M.

You prefer the 1390131 over the 1390653 with the industrial square black badge?

Just curious about your opinion, not saying youre wrong for liking one or the other.

[duality]

Interesting about the part inventory not being cleanly separated between generations of this keyboard. I guess that leaves room for some variability. Good to know guys.
Thanks!

[hellothere]

but I thought the older ones had a colored hue about them...

"older" is probably 1986 for sure and maybe 1987

Great keyboard, I would say that is the best possible Model M.

Dunno about the 101-key, but my 1987 122-key has a "silver" plate; no rainbow. My Model F has the rainbow.

Taste the rainbow. Mmmm. Rainbow.

[Redmaus]

101-key, but my 1987 122-key has a "silver" plate; no rainbow. My Model F has the rainbow.

Taste the rainbow. Mmmm. Rainbow.

MMMMMMMmmm

IMG_0658.JPG (4.29 MiB) Viewed 4446 times

[hellothere]

Very shiny.

I'm almost completed with my Model F overhaul, so I'll be seeing more of that shiny in just a few days.

[clickykeyboards]

Some additional examples of model M keyboards with shiny, curved, steel backplates.

1390131-shiny.jpg (623.33 KiB) Viewed 4318 times

source: early 1986 IBM model M (1390120) Made by IBM 12 JUNE 86
https://clickykeyboards.com/product/ear ... 2-june-86/

DSC07966-scaled.jpg (560.28 KiB) Viewed 4318 times

source: early 1986 IBM model M (1390120) Made by IBM 11 MARCH 86 https://clickykeyboards.com/product/ear ... -march-86/

[fohat]

You prefer the 1390131 over the 1390653 with the industrial square black badge?

No, the industrial model is far more expensive and desirable, but I don't think there are any substantial functional differences between them and the standard models.

[OldIsNew]

For sure many 1390131's have the "silver" instead of "rainbow plates". From what I've seen and from the 1390131's I've managed to acquire, it seems the early 1986 models are most likely to have the "rainbow" back plates. All of them are excellent boards but the "rainbow" plate ones do seem to have a little more heft - and i think that's fits the overall trend towards lighter (cheaper) as time went by.