Parallel I/O

[barney]

Mike, Any plans to add a 88-4PIO? Hopefully that can emulate hardware interrupts?

[AltairClone]

I hadn't planned on implementing the 88-PIO -- but anything is possible! What kind of equipment were you hoping to interface with it?

[barney]

Nothing definitive, I just wanted to toss the idea out. General examples, connecting digital signals from experimental breadboards for training/education. Or recreating an (at the time) amazing demonstration of a microcomputer reading voltages and displaying them on the terminal by an HP traveling road show. Back in 1976 that was pretty hot stuff and I can remember the experience in detail.

For inputs: having some ADCs convert power supply voltage levels, temperature, or humidity and have the Altair log them. Read X-10 signals in the power line. Hook a serial port to an X-Bee module controlled by PIO lines and transmit/receive data wirelessly, like from a weather station or solar electric system. With some dedicated sound hardware, maybe the "ding" of an ASR33,or the chuffing of a paper tape reader/punch. An LED based binary clock display.

On my 1977 Vector-1 I had a Comemco 7D+A and it was a hoot to play with, errr... I mean conduct experiments. It had a two axis joystick with 4 buttons which I used to create a maze on the VDM-1 screen.