IBM Model C

[Manyak]

Just in case anyone has some interest in modding it to be AT compatible.

http://cgi.ebay.com/IBM-Vintage-Clicky-Keyboard-Square-Metal-Logo-PN5640991_W0QQitemZ200256089094QQcmdZViewItemQQptZPCA_Mice_Trackballs?hash=item2ea0316c06&_trksid=p3286.c0.m14&_trkparms=65%3A1|66%3A2|39%3A1|293%3A1|294%3A50

Judging by it's size I'd say it puts the Model M to shame, at least in terms of durability.

[Mercen_505]

Oooh... those don't come around very often. The blue switch on the top is beckoning me...

[Hak Foo]

The layout is just terrifying.

[ch_123]

Sandy has a pic on his site of one of those disassembled, the innards seem to be identical to that of the Model F - same capacitive contacts, same buckling spring assemblies... Obviously the Model F was the name they gave to their PC-specific capacitive BS keyboards.

I'd love to know what all the Models A, B, D, E and G-L were I assume some were the keyboards of the 3278 and that other terminal of theirs whose name escapes me. The Displaywriter and Datamaster too...

[maxlugar]

Just in case anyone has some interest in modding it to be AT compatible.

http://cgi.ebay.com/IBM-Vintage-Clicky-Keyboard-Square-Metal-Logo-PN5640991_W0QQitemZ200256089094QQcmdZViewItemQQptZPCA_Mice_Trackballs?hash=item2ea0316c06&_trksid=p3286.c0.m14&_trkparms=65%3A1|66%3A2|39%3A1|293%3A1|294%3A50

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The probability of being able to convert the Model C to work with any modern computer is slim to none.

It takes a fair amount of dedicated elctronics to convert the scan codes and enable 2-way communication for a PC/XT keyboard to work with an AT or PS2 computer.  Not to mention the USB converter required to work with a modern Windows machine.

It might be nice to press the Model C keys though...

[lowpoly]

The probability of being able to convert the Model C to work with any modern computer is slim to none.

kbdbabel.org has these conversions available:

IBM PC/XT ---> PS2
IBM 3104 ---> PS2
IBM 3151-3153/3179/318x/319x/34xx ---> PS2

in alpha:

IBM 5291-2 ---> PS2

in development:

IBM RT
IBM 3178
IBM 5251 Terminal Keyboard (parallel interface)

[ch_123]

What's the difference between the C2 and C4? Is that manual on the net?

[ch_123]

Is there also a C3 variant?

[ch_123]

Interesting stuff. I'd like to see that manual if you get the chance to upload it.

[ch_123]

It takes a fair amount of dedicated elctronics to convert the scan codes and enable 2-way communication for a PC/XT keyboard to work with an AT or PS2 computer.  Not to mention the USB converter required to work with a modern Windows machine.

It might be nice to press the Model C keys though...

It's even worse - it's a 3178 protocol keyboard as opposed to XT. Im sure it could be converted, but would probably require more effort than the XT board.

Feel wise... There's a disassembled pic on Sandy's page. Looks just like a Model F. Probably will feel just like an XT F.

Oh, and Webwit, does the manual mention what that blue switch does?

[ch_123]

I was thinking it was something like that, but what is that button with the lock icon that's located where one would expect to find a caps lock?

Sorry for the constant stream of questions, just intrigued by this old beast.

[ch_123]

Ah yeah, I get it now.

The click thing is weird. I had read that old IBM terminal keyboards had a solenoid in them to make a click noise when a key was pressed. I'm sure that this was useful in the old linear boards they had, but for BS boards it seems excessive. Perhaps a concession to those familiar with the old designs?

[keyb_gr]

This is probably why the M has a speaker grill. It is not for the M, but for early terminal board versions of the M.

The RS/6000 boards had a speaker throughout.

[ch_123]

Feels like an F XT, slightly lighter that the F AT I have (or is it an illusion?), but is in build closer to the F AT, with a flimsy plastic bottom. However, it is from '83 (different from the ebay pictures, still 9 of 10 left), while my F XT is from '84. It suggests the difference in feel between XT and AT is not in the better build of the XT.

Sandy claims it weighs 3kg. He also claims that the AT version is heavier than the XT, although somebody recently disputed that figure. It is possible that it's heavier but it doesn't feel so heavy because it's bigger and the weight is distributed over a larger area? I know that's why I think a Filco is heavier than a Dell AT, even though it's the other way around.

The RS/6000 boards had a speaker throughout.

So did the Quiet Touch keyboards weirdy enough (the greased ones, not the rubber domes)

[ch_123]

I tried this out for myself. I weighed it on my bathroom scales (or to be exact, I weighed myself, and then I weighed myself holding the keyboard) Did it three times and got a weight of 2.8Kg for the keyboard and it's cable - exactly the same figure that Sandy gives for the PC/AT Model F.

By means of comparison - the same test gave a weight of exactly 2Kg for a 1993-vintage 1391406 without it's cable.

[maxlugar]

I tried this out for myself. I weighed it on my bathroom scales (or to be exact, I weighed myself, and then I weighed myself holding the keyboard) Did it three times and got a weight of 2.8Kg for the keyboard and it's cable - exactly the same figure that Sandy gives for the PC/AT Model F.

By means of comparison - the same test gave a weight of exactly 2Kg for a 1993-vintage 1391406 without it's cable.

Both the 83-key Model F and 84-key PC AT keyboards were weighed on a postage scale and the results posted in a different thread.  Here they are again:

"I also weighed both to see validate ch_123's premise. The results:

Model F 83-key
5.75 pounds without the cord on the scale
5.95 pounds with the cord on the scale

PC AT 84-key
5.30 pounds without the cord
5.85 pound with the cord.

So it wasn't just an illusion. The 83-key Model F is heavier even though it has a slightly smaller footprint. The 0.45 pound differential is over 7 ounces. You Europeans can do the conversion to kg. Even with the longer coiled cord included, the PC AT is still 0.10 pounds lighter than the original Model F."

[lowpoly]

or to be exact, I weighed myself, and then I weighed myself holding the keyboard

Correct usage of bathroom scales for smaller weights.

[maxlugar]

Hmm.. need better scale.

Hey man, it's good enough for the United States Postal Service...although I'm not sure if that guarantees that it's accurate

However, I can assure you it's more accurate than a bathroom scale

[ch_123]

I didn't expect a bathroom scales to be 100% accurate, but as I said, I've calibrated the scale with a Model M. With cable, and using that system, the scale gives a weight of 2.2Kg, which is what is expected of a Model M of that type and vintage. There's also the fact that Sandy's website gives the same weight. Now, unless Sandy measured his Model F using the exact same type of scales as I did, the likelihood that i'd get the same weight as he did is pretty slim. I'm going to stand by my figures for now.

[itlnstln]

Depends on the scale I guess. I just took a 5 lb weight upstairs and the method gave me a result a full pound off. These digital scales can deceive you with false accuracy

Maybe your 5lb. weight is mislabeled.  I think you need to do more tests.

[maxlugar]

I thought there was a Head Shop on every corner of Amsterdam?  I like the name of this one, The Flying Dutchman!

Webwit should really be called the "Dutch Damager" for his scathing sense of humor

[maxlugar]

Well I have one with 0.05g accuracy but that only goes to 250g. The one I ordered can have a few kg and has a 0.5g accuracy. Both can be calibrated and I have certified calibration weights. That should put an end to it.

Yeah, well I want to see the official stamped and notarized calibration certs from the EU.  Then and only then will I concede that the 83-key Model F is lighter (or the same weight) compared to the 84-key PC AT keyboard.

(And don't even try and forge the certs) :lie:

[Mercen_505]

There are still 8 of these available. If you make an offer, you can get it for considerably less than the ~90 USD that is the "Buy it now" price.

[timw4mail]

There are still 8 of these available. If you make an offer, you can get it for considerably less than the ~90 USD that is the "Buy it now" price.

But what would you do with it?

[ch_123]

There are still 8 of these available. If you make an offer, you can get it for considerably less than the ~90 USD that is the "Buy it now" price.

The C2 model is available for much less here.

But what would you do with it?

Experimentation and modding purposes. They're basically the same thing as a Model F, except cheaper, because there's probably not that many people around who still use 3178s.

[Mercen_505]

But what would you do with it?

It goes in the collection

[Shawn Stanford]

The empty part at the right is were the numpad goes on the C2-C4 models. Ironically, the manual calls the C1 a "75-key data-entry keyboard" and the C2-C4 a "87-key typewriter keyboard".

IIRC: the empty area on the right was for the PF key pad.

[ch_123]

Yep, see the C2 model I linked above.

[Shawn Stanford]

Ass-ton of geek cred there...

Am I correct in my understanding that these are irrevocably incompatible with modern equipment..?

[ch_123]

I think the guy at Kbdbabel has some sort of conversion project in development for the really old IBM terminal keyboards, but I'm not sure whether it will work with these particular models, or whether it will come to anything at all.

Really what I'd love is an old 3278 keyboard from the late 70s. Those things were beasts.

[Shawn Stanford]

Really what I'd love is an old 3278 keyboard from the late 70s. Those things were beasts.

Like this: http://www.recycledgoods.com/7741_IBM_1742705_Keyboard%20for%203278%20Terminal.html


Good lord, they were a nightmare!  Almost as heavy as a manual typewriter, and the keys went down with a meaty 'clunk'. Barely touch-typeable. I was happy-happy to move to the 3179 when they started appearing.

[ch_123]

Ah, interesting to hear from someone who had first hand experience with one. Still intrigued by the original BS keyboards, though I wouldn't bother buying one off eBay because of the weight and associated shipping costs. Ideally one will appear in a skip one day =P

[Shawn Stanford]

Ah, interesting to hear from someone who had first hand experience with one.

:lol:  There isn't a lot of IBM mainframe equipment from the 70s forward that I haven't had my hands on.    Plenty of other IBM-compatible equipment as well.

[ch_123]

:lol:  There isn't a lot of IBM mainframe equipment from the 70s forward that I haven't had my hands on.    Plenty of other IBM-compatible equipment as well.

Mhmm. Any 5251 terminals? Where they also buckling spring? There was a discussion a while back where someone was trying to figure out what the earliest BS keyboard was, and it was between the 5251's keyboard and the 3278s.

[Shawn Stanford]

Mhmm. Any 5251 terminals? Where they also buckling spring? There was a discussion a while back where someone was trying to figure out what the earliest BS keyboard was, and it was between the 5251's keyboard and the 3278s.

According to an article I found on Google, the 5251 was a System/34 terminal. Here's a picture of one from the article:

I never used S/34, although I did use Series/1 and plenty of 3270 terminals from that period. The keyboard in that picture looks a lot like the keyboards from the Series/1 and 3270 terminals of the era. I would expect it to work the same: with a heavy push and a hearty 'thunk'. If those thing used buckling springs, they were automotive...

Of course, someone could ping the owner of this site (http://www.corestore.org/index.htm) and ask him to take apart that terminal.

[Moparx]

Picked one up with an offer of $27.
Another item for my keyboard collection .

[ch_123]

They cut the price in half on these. The C2 model with extra keys is cheaper though, oddly enough.

[Mercen_505]

I got my model C board in the mail today.... quite an odd keyboard indeed. The board is pretty odd in that the keycaps look brand new, yet the case and board itself are in pretty poor shape. I just opened it up to take a peek inside, but I probably won't do any cleaning for a few weeks. I still have 3-4 other boards that need cleaning as well, including my AT model F. Interestingly, the label on the backplate lists it as a model F. The keys have a sturdy and consistent feel somewhere in between the rock solid Model F (XT) and the not nearly so nice Model F (AT).


Also, I bought one of these, for the lulz. It was cheap enough to warrant a closer look

[ch_123]

nterestingly, the label on the backplate lists it as a model F.

This doesnt surprise me at all... pics?

[Mercen_505]

Oh yeah baby, Model C all the way. Did you get the C1 or C2?

I'm assuming it's a C1. It looks like the one in the pic toward the top of the thread. I really do enjoy the action on the keys... very pleasant.  I need to find enough time to post the 8 hojillion pics I've taken on my keyboards, but I've got a software project I'm trying to finish and it's eating my lunch, as we say around these parts  ^_^

Also, I'm lazy.

[Moparx]

I received mine today.

[Moparx]

Yours says MOD M..

Yeah. No idea why though.

[Moparx]

A few internal shots:




I'll be having some cleaning to do this weekend.

[Shawn Stanford]

They key layout on that thing is like nothing I've ever used. That is a weird-ass layout...

[timw4mail]

That looks more familiar. With the big ass capacitor or whatever it is separated from the rest.

I think it's an inductor, the opposite of a capacitor.

[Mercen_505]

Ah, I see the internals of your board are as dirty as mine. Mine also has the holes in the chassis where the manual fits.

[ch_123]

A Model M Model C? Does it have membrane BS or capactive BS?

[Moparx]

A Model M Model C? Does it have membrane BS or capactive BS?

It is capacitive.

[Mercen_505]

A Model M Model C?

I wonder if that is a clerical error? Mine says Mod C1.

[Mercen_505]

Makes sense, then.