Heathkit H8

 
Trionyx T-H90 backplane
Front panel
H19, H8 and Z87
H19
H8
 
Heathkit H8, ca. 1981

CPU: Z80 @ 2.048MHz
RAM: 48KB
Floppy Drives: Two SS hard-sectored drives at 100KB each (Z87)
Display:  
Ports: 4 RS-232
Model: H8
Serial No.: 02751
OS: HDOS
ROM: 4KB
Original Price:
Notes:

This system has the following boards:

  • H8-16 16K Static RAM 85-2197-1
  • H8-17 H17 Diskette Controller Board Hard-sector 85-2204-1
  • DG-32D 32K Memory Board jumpered for Z80
  • HA8-6 Z80 CPU 85-2609-1
  • Control Circuit Board 85-1935-1
  • H8-4 Multi Port Serial I/O 85-2556-1
  • Trionyx T-H90 backplane

The HA-8-6 Z80 CPU board was heavily modified, for unknown purposes. I was forced to remove all the modifications and restore the board to its default state. The DG-32D RAM board also had a bad 4116 chip and the front panel had a bad 2N3904 transistor in the reset circuit.

The last three pictures show the system running CP/M 2.2.04 from a Z87 drive unit. I've configured the H8 with a Z80 board from a recent Norberto Collado design, and the H17 controller. The Z80 board has 64KB of RAM, two serial ports and a real-time clock. Details, here.

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Last updated on Monday, January 25, 2021