Remapping the HP150 keyboard

-----Oorspronkelijk bericht----- Van: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] Namens Tony Duell Verzonden: vrijdag 17 april 2009 19:39 Aan: cctalk at classiccmp.org Onderwerp: Re: Remapping the HP150 keyboard an HP120 or What good would that do? This is not an interface module that connects between the HP120 and an unmodified HP150 keyboard (if it was, I wouldn't have bolted it to the keyboard, cf the interface for the 262x keyboard I described last week). It's a modification to the HP150 keyboard tht electrically connected by a piece of 14 way ribbon cable and a DIL header in place of a 4024 chip on the keyboard PCB (Desolder the chip, solder in a socket. P,ug in a 4024 to return the keyboard to the original HP150 circuit, or this modification board to make it work with either the HP120 or HP150). Making an interfaec to connect between the HP120 and an unmodified HP150 keyboard would be a lot harder (and would almost certainly need a microcontroller). You'd have to scan the HP150 keyboard (generate clock and reset pulses, grab the state of the keydata line), then store the state of all the ekys and transmit them to the HP120 in accordance with the clock and reset pulses from that machine. I did consider doing this, but the modification to the keyboard turned out to be a lot easier. -tony