Chromedome45
Veteran Member
Just when I was planning on slimming down my vintage computer collection this little gem showed up on Craigslist. It is a Heathkit H-8 with the following extras.
H-17 Floppy disk cabinet and 3 disk drives.
HA8-6 Z80 processor board.
Dg-64 64k RAM memory board.
H8-4 4 port serial board
H17 Hard sector floppy controller board
H37 Soft sector floppy controller board
All assembly and users guides for all the above listed items plus extras
Zenith/Heathkit CP/M 2.2 manual and soft ware...A nice bonus there.
And some additional items
When I 1st attempted to power it up it would not. Heard some crackling sounds and shut the system down. Checked the usual Tantalum capacitors because they like to short and found 2 of them bad. One on the Memory board and one on the CPU board.
After replacing them I tried to turn on but would not boot up. Turns out I had to reconfigure the CPU board not to interface with the H37 floppy controller which I needed to do for preliminary testing. Also there is a 16 pin DIP cable that interconnects the 2 boards that had broken pins on it.
I had to set jumpers on the CPU board to not talk to the H37. After I did that it started up. But still was a little flakey on the amount of memory reported
I resolved the memory issue by building a memory card I got from les Bird (small board in pics of H-8 Interior) a couple of years ago and installed it. It reported the memory amount correctly and passed the memory tests. The other board still does not report memory correctly so I put it away for testing at a later date.
regarding the 16 pin DIP cable I wound up ordering a couple of 16 pin DIP headers and rebuilt that cable so the CPU could talk to the H37 board.
I have since put jumpers back in place on the CPU board to talk to the H37 floppy controller and connect the DIP cable and have booted CP/M. So right now it is working good. So far.
Also had to replace the 2000uF Cap on the power supply board inside the H17 floppy cabinet. Was bulging and cracking.
H-17 Floppy disk cabinet and 3 disk drives.
HA8-6 Z80 processor board.
Dg-64 64k RAM memory board.
H8-4 4 port serial board
H17 Hard sector floppy controller board
H37 Soft sector floppy controller board
All assembly and users guides for all the above listed items plus extras
Zenith/Heathkit CP/M 2.2 manual and soft ware...A nice bonus there.
And some additional items
When I 1st attempted to power it up it would not. Heard some crackling sounds and shut the system down. Checked the usual Tantalum capacitors because they like to short and found 2 of them bad. One on the Memory board and one on the CPU board.
After replacing them I tried to turn on but would not boot up. Turns out I had to reconfigure the CPU board not to interface with the H37 floppy controller which I needed to do for preliminary testing. Also there is a 16 pin DIP cable that interconnects the 2 boards that had broken pins on it.
I had to set jumpers on the CPU board to not talk to the H37. After I did that it started up. But still was a little flakey on the amount of memory reported
I resolved the memory issue by building a memory card I got from les Bird (small board in pics of H-8 Interior) a couple of years ago and installed it. It reported the memory amount correctly and passed the memory tests. The other board still does not report memory correctly so I put it away for testing at a later date.
regarding the 16 pin DIP cable I wound up ordering a couple of 16 pin DIP headers and rebuilt that cable so the CPU could talk to the H37 board.
I have since put jumpers back in place on the CPU board to talk to the H37 floppy controller and connect the DIP cable and have booted CP/M. So right now it is working good. So far.
Also had to replace the 2000uF Cap on the power supply board inside the H17 floppy cabinet. Was bulging and cracking.
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A really mean machine! 
