Page 2 of 2

PostPosted: Mar Sun 01, 2009 6:56 pm
by vbriel
or (c) interfacing 3.3V Propeller to 20 year old 6821? This one threw me. I worked on this issue in the firmware and it just is not the firmware that I could find. The resistor above the ASCII keyboard connector was suppose to keep the strobe pulled low until used. I ended up needing another resistor on the other side of the latch. The latch keeps the ASCII keyboard from interferring with the PS/2.

There are 3 possible keyboards on the replica 1 TE. First is an ASCII keyboard connected to the 16 pin DIP, the 2nd is the PS/2 keyboard and the 3rd is the serial port. The serial port data comes in and gets treated like a keystroke. The keyboard port on the 6821 is really a busy port.