IBM Model M keyboard

The IBM Model M series of keyboard began life in 1984.

IBM Model M, IBM PS/2 personal computer

Model M keyboard, made famous in early 1990s with IBM's PS/2 personal computer, and earlier.

I used it for a few months in 1990. Click-clack click-clack, but a real joy to use.

Typing on an IBM Model M Keyboard

IBM Model M Key Switch Mechanism

What people love about this keyboard is its superior tactile feedback. The key switches are based on a mechanism known as buckling spring. When you put pressure on a key, after a certain point, =click!=, it sucks you down. That means, you get a clean, precise, feel whether the key is pressed. A drawback is that it is rather loud. The sound came from the spring hitting the key's inner wall. It's crispy and precise.

Many modern, rubber dome based keyboards are also loud, and makes ugly “squeak”, “clunk”, “thud” sounds, due to bad acoustic housing of the keys and plastics rubbing each other.

IBM Model M type 3192-G keyboard, 1985

this keyboard is actually one of the few that you won't see a control key on.

It was made for use with a 3270 terminal connected to a Mainframe where there was no use for a control key.…

The extra keys are related to different shortcut macros that are used in the Mainframe. Meaning, there were 24 different functions to use.

The PA keys are for different Program Access functions. PA1 is the attention key which is like hitting ctrl+C to halt a function. PA2 is used to reshow a screen. So, if you accidentally hit the clear key before you were done viewing something, you can hit PA2 and reshow it.

the PA1-3 keys have different functionality depending on the environment. I have only used PA1 in TSO to send an interrupt.

From what Haiduk has told me, that entire left side was usually made up of custom keys that programmers put there for specific tasks.

PF19 is scroll up and 20 is down.

Here's a list of the default keymaps used in Personal Communicator (another 3270 emulator). http://publib.boulder.ibm.com/infocenter/pcomhelp/v5r9/index.jsp?topic=/com.ibm.pcomm.doc/books/html/emulator_reference11.htm

[by Vance Morris and Brett Dawson, from https://plus.google.com/+VanceMorris/posts/79HtVgkNdAD]

IBM Model M 3193 keyboard, 1988

This keyboard does not have a Control key.

lots more photos of model M at http://snowdog993.imgur.com/

IBM Model M2

Model F vs Model M

Model F came first.

• Model F is buckling spring, with electrostatic capacitance as electric switch. Model F were made from 1981 to 1994.
• Model M is buckling spring, with metal contact as electric switch.

[see Guide to Keyboard Key Switch Mechanisms]

Unicomp

Unicomp keyboard are clone of the IBM Model M keyboard, that you can buy today.

Unicomp Keyboard

See also: Affirmative Keyboard