What is it?

The H8-FD-RS232 is a floppy disk controller card for the Heathkit H8 computer. It has a hard sector controller (H17 compatible) and a soft sector controller built around the WD37C65 FD controller chip. It also includes 3 configurable RS232 ports. With this single card you can replace the H17 Controller and H8-4 Mult-Serial port card in your H8 computer. The original soft sector floppy disk controller for the H8 computer was called the H37 and was based on the WD2797 controller chip. The WD37C65 on this card is not fully compatible with the WD2797 and currently is not supported with HDOS and Heathkit CP/M. Support is ongoing and will be posted on the website when we have something working. However, when used with my RomWBW CPU board the WD37C65 is fully supported and you can read/write to soft sector 3.5in floppy disks.

Included:

• FD-RS232 PCB
• 2 DB9 SERIAL CABLES
• WD37C65C PLC44 CHIP
• S2350P UART FOR H17
• PLC44 THROUGH HOLE SOCKET
• 1.8432MHZ OSCILLATOR

Why did you make it?

I wanted to combine the H8-4 Mult-Serial I/O board with the H17 Disk Controller board and the H37 Disk Controller board. In addition I wanted to modernize the design by using chips that are readily available.

What makes it special?

H17 hard sector controller plus WD37C65 soft sector controller. The H17 and RS232 ports are plug-n-play ready to use with HDOS and Heathkit CP/M.

Build a complete H8 computer (without chassis):

• H8 FRONT PANEL

• H8 Z80 CPU BOARD

• H8 FLOPPY DISK/RS232 BOARD (this board)

• H8 BACKPLANE

• ATX POWER SUPPLY