[sebhc] My H8 Systems

Carroll Waddell CarrollWaddell at sc.rr.com
Tue May 25 08:16:11 CDT 2004

Thanks for this information. I purchased an H17 controller board, but 
the ROM and RAM chips are missing. Perhaps I won't need them to use it.

Dwight K. Elvey wrote:

> With all of the talk about H8's I decided this weekend
>to actually power one up( I do have a working H89 ). I have two
>of the H8's. One is the older type with the 8080 and the
>other is the newer type with the Z80. I only brought up the
>Z80 one. I used my variac and brought the voltage up slowly over
>about 1 hour time. At first it was flakey. I removed the first
>RAM card and switched the next to start at address 0. It then
>booted fine. I gave the card a quick ohm meter check and there
>didn't seem to be any issues with it. I reconfigured the
>addresses back to the original and it was then working. It boots
>to the monitor just fine.
> I guess the connector needed a little wiping action.
>I've not done much in the way of a RAM test yet. I'll most
>likely write a 13n march for it. It has a H17 controller
>so I can try booting a disk. I should note that the controller
>has both the ROM and the two RAMs missing. I suspect that this
>is what one does when there is the XCOM8 with a full 64K of RAM.
> I have another controller board with the RAM and ROM. I expect
>to run this on the 8080 machine. This box doesn't have a full complement
>of RAM. It has only 4 8K boards installed but I have 3 other
>8K boards ( one not fully populated ). The 8080 has the
>combination cassette/serial board ( H8-5 ) while the Z80 machine
>has the 4 port serial board ( H8-4 ).
> I only have the one H17 drive box so I'll need to share that between
>machines. I have a H19 but I'm not sure what its status is yet.
> All good fun.
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