IBM 1390120 & 1390131 - The Early Ms

[nowsharing]

I'm awaiting the delivery of both 1390120 and 1390131 Model Ms, (the M predecessors to 1401), and I am interested to know more about them. I've found many pictures online, but very little background info. I realize the obvious, that the 0120 is a 0131 without lights, they have a metal badge, extra key stabilizers (on numpad + and Enter), and both came with black cords. But I've also read reviews that depict both models as being heavier and more clicky than the later Ms.

Does anyone know what's going on inside of these early Ms that makes them heavier, and if they used a different spring or switch mechanism than the later Ms? What other differences are there, if any, from newer Ms?

1390120

1390131

Metal IBM Logo & two extra stabilizer bars on numpad Enter and +

[wellington1869]

Does anyone know what's going on inside of these early Ms that makes them heavier, and if they used a different spring or switch mechanism than the later Ms? What other differences are there, if any, from newer Ms?

when you get them, open them up and post pics - i too would like to know if the switch mechanism is different...

I used an early model (an F model, I think) when my dad brought home a very early 8086 'ibm pc' in 1982 (i think it was). I used that keyboard for several years, maybe thru 1985, at home.  It was a long time ago so I have to rely on memory (which can be pretty poor) but I seem to recall the keys being deeper, louder, chunkier, pingier than my current 1401. Really more enjoyable (tho not as civilized) as the 1401 in comparison.

[nowsharing]

I actually won't have access to mine until Nov or Dec. I plan on writing a review and posting some pics then though.

[itlnstln]

I actually won't have access to mine until Nov or Dec. I plan on writing a review and posting some pics then though.

That's a long wait.

[wellington1869]

I actually won't have access to mine until Nov or Dec

thats a pity  
Thats a long time to wait!

[Manyak]

I haven't opened up either of my model Ms, but I can tell you this from now - the springs on the 131 are a lot stiffer. The 401 is really easy to type on, but the 131 needs you to type...as laurie put it once...like you're trying to resuscitate 104 dead rats.

Speaking of which....does Unicomp sell replacement springs? I really need to lighten this board up a bit.

[itlnstln]

Speaking of which....does Unicomp sell replacement springs? I really need to lighten this board up a bit.

Yes.

[ch_123]

I used an early model (an F model, I think) when my dad brought home a very early 8086 'ibm pc' in 1982 (i think it was). I used that keyboard for several years, maybe thru 1985, at home.  It was a long time ago so I have to rely on memory (which can be pretty poor) but I seem to recall the keys being deeper, louder, chunkier, pingier than my current 1401. Really more enjoyable (tho not as civilized) as the 1401 in comparison.

The Model Fs have capacitve keyswitches compared with the "spring-over-membrane" that the M does (personally I think they're a much nicer board than the Model M). I can't really imagine how that causes it to have such a different feel, so I think it may different springs as well.

The Model F also feels lighter to type on that the Model M, so I doubt the older Model Ms are based on the same tech if they feel stiffer.

[nowsharing]

webwit & manyak: Did you notice the weight difference that some people note?

[Manyak]

webwit & manyak: Did you notice the weight difference that some people note?

Definitely. Not by much, but you can still tell that it is.

Though one thing I've heard people say is that the weight is a side effect of it being made sturdier, which I can't say I've noticed in any way. Maybe if you tried using the keyboards as baseball bats or drove over them with a dump truck you might find a difference, but not while typing. :biggrin1:

[Mercen_505]

I have a 131 as well as a 120, both in pristine condition. The boards feel a little bit heavier than later model Ms, and the housing has considerably less flex to it. They feel like they are absolutely indestructible; the weight and sturdy frame make quite an impression. My M3 feels chintzy in comparison. If you break down an early M for cleaning you'll find the top and bottom halves of the housing are very stiff, whereas later models have more flex to them, and will bend and wobble if you hold them at one end and wave them in the air a bit. I don't prefer to use my M3 for comparison purposes, because quite honestly it's the most shoddy of all my M boards from a construction/quality of materials standpoint... but it's black so it gets a free pass

I spent every day since ~1991 or so typing on a 131, and when I finally retired it a few months ago it was still in near perfect condition. I could tell that the springs had loosened up considerably, but after writing volume after volume of technical manuals, as well as hundreds of thousands of lines of code, it could be forgiven.

[lowpoly]

If someone has a spare metal logo, I still need one. :smile:

[Qwertyuiop]

I wonder why there were 1390131 keyboards manufactured as late as 1996?

A few years ago clickykeyboards had these, new, with the "manufactured fro IBM by Lexmark" label on the back; the one I'm looking at right now is dated 3/19/96, Plt. code is TC1.

The keys on this one feel the same, spring tension-wise, as the 1391401 I'm typing this on. This particular 0131 came with the extra-long gray cable with a PS/2 connector, and it's in one of the plain brown boxes like keyboards that came with systems rather than the box with logos etc.

There's also a little problem; the top half of the housing has tolerances that are a bit off, the top of the right arrow key rubs against the case and sticks. The left arrow as well but not quite as much. There's visibly more space between the housing and the keys on this 1401.

[Hak Foo]

By 'stabilizers' do you mean the little plastic rings in the unused second sockets for + and enter, or wires like the spacebar?

I'm pretty sure my 1990 1391401, at least, had the plastic rings.

Lowpoly, you might be able to purloin one from other IBM kit of the vintage, and perhaps remove any additional model designation.

[nowsharing]

I wonder why there were 1390131 keyboards manufactured as late as 1996? the one I'm looking at right now is dated 3/19/96

Could you post pictures of yours? I've never heard of any with dates outside of '86 or '87 either, it sounds very interesting.

By 'stabilizers' do you mean the little plastic rings in the unused second sockets for + and enter, or wires like the spacebar?

The 0131 & 0120 have extra stabilizer bars (wires) under two numpad keys.

[watduzhkstand4]

I am very interested to check out the internals of this thing

[Qwertyuiop]

Could you post pictures of yours? I've never heard of any with dates outside of '86 or '87 either, it sounds very interesting.

Unfortunately I don't own a camera. :sorry:

However, I finally found clickykeyboards' page on it here http://www.clickykeyboards.com/index.cfm/fa/items.main/parentcat/9230/subcatid/0/id/156756

Maybe I'm wrong about the cable length.

[nowsharing]

However, I finally found clickykeyboards' page on it here http://www.clickykeyboards.com/index...id/0/id/156756

Nice find! I wasn't expecting them to still have the metal logo, it's an amazing keyboard. Just when I thought I had overcome my desire for more Ms, this turns up. It must have been the 10 year anniversary 0131 Very cool indeed.

[ch_123]

Was the '0120 in any way XT compatible? If not, why did it not have indicator lights?