Z80 CPU board for the Heathkit H8 computer with the following features

• 2 to 16 MHZ software controlled
• ORG0 built-in
• 82C55 based IDE built-in
• RS232 at port 350Q built-in
• Board is reconfigurable from H8 Z80 mode to RomWBW mode via jumpers
• 512K RAM (AS6C4008) - 64K used in H8 mode
• 512K ROM

What's included

• Z80++ PCB
• DB9 RS232 cable
• 2MHZ Front Panel Adapter

Why did you make it?

I wanted to merge the excellent features of my RomWBW CPU board with the standard H8 Z80 CPU board. In H8 mode can be used with the H17 disk controller so you can boot native Heath hard sector disks but also you can boot HDOS and Heath CP/M directly from the compact flash drive.

What makes it special?

Can be configured via jumpers for H8 Z80 mode (HDOS/CPM bootable from compact flash) or RomWBW mode (CPM/ZSDOS/Forth/UCSD P-System and more). Can boot from H17 disk drive in H8 mode or from compact flash in both H8 and RomWBW mode. To change modes you need to move 7 jumpers and swap out the ROM chip. The 2MHz adapter plugs into IC103 of the front panel and allows the front panel to work at speeds greater than 2MHz.

Build a complete H8 computer (without chassis):

• H8 FRONT PANEL

• H8 Z80 CPU BOARD (this board)

• H8 FLOPPY DISK/RS232 BOARD

• H8 BACKPLANE

• ATX POWER SUPPLY