lk401 keyboard protocol?

From: Tony Duell <>
Date: Sun Feb 22 17:23:18 2004

> Michael Sokolov wrote:
> >der Mouse <> wrote:
> >
> >
> >
> >>Where did you find this definition?
> >>
> >>
> >
> >It will be the IFCTF definition when I get around to posting it. Though it will
> >say "ASCII or ASCII extension", and I'm sorry that I didn't make the last bit
> >clear in my message you are replying to.
> >
> >
> So those thinks plugged into IBM mainframes that look a lot like
> keyboards, are not
> keyboards, because they transmit EBCDIC? And those things on those old
> teletypes
> aren't either because they use BAUDOUT?

I am typing this message on a flat thing with about 101 buttons on it. It
connects to my PC by a serial link, but the data carried is not ASCII, or
anything like it, the device sends 'scan codes'.

The technical reference manual calls this thing a 'Keyboard'. I've always
called it that too, and don't intend to change....

Incidentally, when looking at the switcjh matrix wiring of these
keyboards-to-everyone-else devices, I've noticed that

Some manufacturers wire the matrix so that the switch position is related
to the keycode that's sent (this simplifies the encoding electronics or
software driver)

Others wire the matrix so that it corresponds to the physical position of
the keys on the keyboard (this simplifies the PCB layout)

Still others do neither (%deity knows why...)

Received on Sun Feb 22 2004 - 17:23:18 GMT

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