The software for the programmer is in two parts, the “firmware” that runs on the ATMEGA8, and a program intended to run on a Linux machine which sends a file to the ATMEGA8 which it then writes onto the EEPROM. Both bits of software are available on my github account. This is not the nicest code I’ve written, but it… Read more »
The circuit is relatively simple once the block diagram has been devised. For the serial port, a USB lead meant for interfacing to the RS232 port on a mobile phone was used instead of something more conventional like a MAX232 level shifter. Something like this from ebay would also work. On the ATMEGA8, the whole of PORTB is used for the… Read more »
My 6809 Single Board Computer will need, at least, the following: A CPU Some RAM Some ROM Some I/O devices While there are other options for somewhere to hold a core set of routines*, the traditional method is with a ROM. But a ROM needs to be loaded with code via a programmer. For the ROM a 28C256 is a… Read more »