[Coco] keyboard

[peak at mail.polarcomm.com]

How about this;
use a coco keboard with a pic 16c55 port a to scan colums 
port b to read rows port c to send serial data.
At the other end(computers PIA) use 74148 to change 8 column 
lines to 3-bit binary added to 7-bit code from serial to 
parallel shift register(which comes from cable)
then use the 7-bit plus the 3-bit data to a small prom.
This gives 10-bits which would be connected to the address 
lines of a 1k prom. The data lines from the prom would then 
be connected to the PIA's row port. The logics is thus:

If column number plus keycode then row!!

It would be simple matter for someone like me to build this 
hardware. The only thing is I dont know any pic code nor do I 
have a PIC programmer or prom burner at this time.
any more ideas??
eric