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geekhack Community => Keyboards => Topic started by: microsoft windows on Sun, 20 December 2009, 10:43:55

Title: How do you tell a 122-key Model M from a 122-key F?
Post by: microsoft windows on Sun, 20 December 2009, 10:43:55

I've been wondering for a while with the old 122-key terminal keyboards how to tell a Model M from a Model F (besides the label). I've been thinking for a long time about getting a Model F, but I'd get the 122-key varient and convert it since they're cheaper. A lot of sellers on the ebay site show pictures of the keyboards but don't tell their part number or model. So, can anyone here shed some light on the differences between the two?

Thanks!

Title: How do you tell a 122-key Model M from a 122-key F?
Post by: ch_123 on Sun, 20 December 2009, 11:06:39

If you're looking at them from the top, the Model F's F-keys only grey (although there are some Model Ms that have them too), whereas the Model M ones are a mix of white and grey. Also, the underside is made of metal as opposed to plastic.

Best way to find out? Ask the seller. If they aren't prepared to answer, you shouldnt buy from them anyway.

EDIT: Some of the latter ones are marked Model M, although I think that they use Model F style buckling springs... Terminal boards are as confusing as Alps.

Title: How do you tell a 122-key Model M from a 122-key F?
Post by: ch_123 on Sun, 20 December 2009, 11:22:23

There are some Ms that have the 'hat' keys too. Asking the person to read the label is the only accurate way.

Title: How do you tell a 122-key Model M from a 122-key F?
Post by: microsoft windows on Sun, 20 December 2009, 11:25:11

I've seen some Model M's with the old-fashioned Ctrl and Alt keys and the gray function keys. But, I have noticed that at least the Model F's I've seen have a straight plug but the Model M's have a right-angle plug. Can anyone provide any counter-examples?

Title: How do you tell a 122-key Model M from a 122-key F?
Post by: microsoft windows on Sun, 20 December 2009, 11:33:23

I'll do some more research and touch bases with you all about that.

Title: How do you tell a 122-key Model M from a 122-key F?
Post by: ch_123 on Sun, 20 December 2009, 11:35:56

F-variant

(http://geekhack.org/picture.php?albumid=11&pictureid=98)

Also, there's the 104 variants

(http://geekhack.org/picture.php?albumid=11&pictureid=101)

Title: How do you tell a 122-key Model M from a 122-key F?
Post by: microsoft windows on Sun, 20 December 2009, 13:13:24

Quote from: ch_123;143919

F-variant

Show Image

(http://geekhack.org/picture.php?albumid=11&pictureid=98)

Also, there's the 104 variants

Show Image

(http://geekhack.org/picture.php?albumid=11&pictureid=101)

Those "tenkeyless" F's are pretty hard to come by. I know that there are rubber dome and buckling spring versions of it as I have seen a few examples of each on Ebay. Brian also at least had (or may still have) some shrink-wrapped rubber dome versions on his RareKeyboards  ebay store.

With the "hat" keys, I think that the Model F's and early Model M's from 1986 or 85 are the only ones that have them. I haven't seen any with the ovular logo and the hat keys.

Title: How do you tell a 122-key Model M from a 122-key F?
Post by: microsoft windows on Sun, 20 December 2009, 13:43:27

Aren't the Model M 122's without the lock lights but still with the ovular logo terminal ones?

With terminal keyboards, I want to get a Model F anyway so I can have the capacitive springs.

Title: How do you tell a 122-key Model M from a 122-key F?
Post by: microsoft windows on Sun, 20 December 2009, 13:52:56

The main reason behind my interest in terminal keyboards is getting a cheap Model F with nice keys.

Title: How do you tell a 122-key Model M from a 122-key F?
Post by: microsoft windows on Sun, 20 December 2009, 14:05:32

It depends on the type of terminal the keyboard was made for. There are some Model F's that are AT-compatible with just rerouting the cable.

Title: How do you tell a 122-key Model M from a 122-key F?
Post by: ch_123 on Sun, 20 December 2009, 15:18:04

Quote from: kishy;143981

Capacitive springs...that doesn't sound right, I think the springs are larely interchangeable between M and F, no? What you mean is the PCB....

Nope, the springs are not interchangeable, it has been tried and it failed. The length/number of coils of the spring are tweaked to work with the underlying mechanism.

Quote from: microsoft windows;143957

Aren't the Model M 122's without the lock lights but still with the ovular logo terminal ones?

Not necessarily. There are terminal Model Ms without them that were designed to be used with terminals or POS equipment. The ones with lock lights were terminal emulation boards. They were designed to be connected straight to a regular PC with a PS/2 cable and act as a normal keyboard. When used with additional software, the additional keys could be used to communicate with a mainframe.

The Model Fs are a bit different because although they were terminal emulator keyboards, they had their own connector that plugged into a special ISA card that you had to pay extra for. Whilst it uses the same connector, I'm not sure about the compatibility of the "Space Saver" Model F, which designed to be used with a terminal only. (a 3290)

Title: How do you tell a 122-key Model M from a 122-key F?
Post by: ch_123 on Sun, 20 December 2009, 15:27:04

It used Scancode 3 as far as I know. I'd say that they just took the terminal protocol and dumbed it down a bit.

The 3270 PC keyboard was designed solely to be used with the 3270 PC. Why did it need a card? My guess was that the XT protocol was unsuitable for adaption to a fullsize terminal board. Could also have been the bureaucracy demanding 'product rationalization' to prevent easy adaption of regular XTs into PC3270s. Whilst maybe not quite the same as later boards, in terms of application, it was a terminal emulator board.

Title: How do you tell a 122-key Model M from a 122-key F?
Post by: sethstorm on Sun, 20 December 2009, 15:55:51

Quote from: kishy;143981

It's about 95%, and no compiling or what have you is needed. There is a finished file available for 2000/XP users...and Vista/7 with some bugs (and my own experience is it didn't work at all, but that's one person).

It's the driver swapping procedure that gets messy. I still haven't figured out a way to explain that in words which does not sound confusing, despite it being a really easy process.

None is needed, but if you do want to have it report those additional keys without remapping software, the DDK is quite useful to have if you know anything about it.  

I'd not mind if I could just have it properly report them as extra function keys (or even better, multiple scancodes) at a lower level than remapping software can do.  But then I'd just be better off with a Cherry RC128(better solution)/G86-634x0(decent, what I have right now) + M13 if I really just wanted to do that.

(see signature for my DDK article)

Title: How do you tell a 122-key Model M from a 122-key F?
Post by: AndrewZorn on Sun, 20 December 2009, 20:34:33

i never noticed that i didnt know.