Wednesday, November 15, 2017

Tiny AVR based project to reset Z80 (or any other CPU) by a serial line

For the modern DIY computers that's normal to be connected by serial port. And in most of cases that's the only way how the communication is made.

But all that Z80 and MC68000 CPUs sometimes HANGS! (Well, do not blame them, blame yourself for a buggy code). But no matter - we have to reset them. And to do that remotely.

So this tiny tool does that: it uses 2 lines from your DIY computer - the reset line and TTL-level RX line of the console. To initiate /RESET, just send break.

You need ATTINY2313, avr-gcc compiler, mm...avrdude and (probably) to edit 2 lines of code in main.c:
#define F_CPU 12000000L
#define BAUD 57600

First is the freq of yours' quarts, the second is the baudrate of your console.

And all that work for me.

Get it all here