Re: C64 Tower - keyboard ======================== Subject: Re: C64 Tower - keyboard From: martijnb@mud.stack.nl (Martijn van Buul) Date: 1998/03/11 It occurred to me that Paul Albers wrote: > > Can't an old PC keyboard also be hardwired like that? I realize it > would > take some time an effort, but I think it would be worth it if there was > no better way. Theoretically, yes... Practically: No. A PC-keyboard is basicly a similiar matrix which is converted to scancodes in the actual keyboard itself. If you'd want to make a PC-keyboard to have the same matrix as a C64-one, that would mean that you'll have to change the PCB of the keyboard itself. (that is: make a new one!)(which could be used on only _one_ type of keyboard. A _slightly_ different model wouldn't work). Making a small circuitry that emulates a C64 keyboard from the scancodes it receives from the PC-keyboard, that'd be a far more better idea. Actually, all you need is a microcontroller, reading the COLUMNS-port from CIA1 port A, and writing the appropriate LINES-value to port B, depending on the keys pressed. A simple 68HC11 would do nicely. It has enough I/O ports, enough RAM, enough EEPROM to store the needed program in.... Easy! (PS: I'm told that XT-keyboards have a far more easier keyboard interface, since it's a one-way only interface (the keyboard only sends to the computer). An AT-keyboard sends as well as receives data from the computer (the LEDS are controlled that way). However, XT-keyboards are hard to obtain these days...) -- Martijn van Buul, martijnb@mud.stack.nl Tijntje@OuterSpace - 131.155.141.166 3333