A device that allows a host PC to read and write memory on the bus of a Z80 computer (or potentially other CPUs) as well as a few other functions. It makes use of the Z80's BUSRQ / BUSAK feature to gain access to the bus while the CPU is running. The circuit is based on an Atmel atmega1281. The host interface is a bidirectional TTL-level serial (UART) connection that uses a simple hex-based protocol to control the monitor and provide handshaking. The host interface is electrically isolated to allow the target device to be power-cycled properly without being back-powered by the serial signals. This also avoids any risk of SCR latch-up.
This is 6-way single-row header to fit a standard FTDI FT232 serial cable (TTL type.) It will work with the 5V and 3V3 versions.
| Number | Function |
|---|---|
| 6 | Not Used |
| 5 | Serial Out |
| 4 | Serial In |
| 3 | Power In |
| 2 | Not Used |
| 1 | Ground |
See the pinout file