Date: Mon, 7
Jan 2008 08:54:38 -0800 (PST)
From: Fred Cisin <cisin at xenosoft.com>
It would seem that the cheapest way to do it is a
discardable PC.
Input character
print it
loop
Only barely possibly the cheapest. A $2 PIC or AVR or even 8051-
family chip can do the same job for a fraction of the power and space
and noise. And the code is out there--I've seen code for getting
PS/2 keyboard data into both PICs and AVRs. The output side would be
a piece of soup.
And a PIC could be considered "retro"; certainly an 8051 would be.
Both are descended from mid-70's chip designs.
But to answer an earlier question--no, a simple serial-in, parallel-
out shift register won't do the job with a PS/2 keyboard--the
interface has a bidirectional protocol--it just doesn't blindly send
out scan codes.
If anyone is interested, I have a very small bit of 8051 code which reads an attached PC
keyboard,
providing the scan codes over an RS-232 link. It also supports commands to set LEDs on/off
etc.
I specifically avoided using the P1 line in my design (full 8-bits
parallel I/O available even on an 8031), so these are free, making it very trivial to
modify this
to output parallel instead of serial - it
would also be very easy to add a translate table and recognition of
shift/ctrl modifiers so that it would output fully decided ASCII.
Dave
--
dave06a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools:
www.dunfield.com
com Collector of vintage computing equipment:
http://www.classiccmp.org/dunfield/index.html