Heathkit H89 Intro

From: Dwight K. Elvey <dwightk.elvey_at_amd.com>
Date: Wed Feb 12 21:33:01 2003

>From: knightstalkerbob_at_netscape.net
>
>"Jason J. Gullickson" <mr_at_jasongullickson.com> wrote:
>
>>I recently acquired what I believe to be a Heathkit H89. It was
>>assembled a long time ago by my friend's father, contains a single disk
>>drive and a monochrome terminal.
>>
>>My ultimate goal would be to get this thing running CPM and a C
>>compiler, but first I need to figure out if it's working.
>>
>>I've yet to determine if it has a hard or soft-sectored disk controller,
>>but I have some general questions since I don't have any documentation.


Hi
 Sorry, I lost the first message.
 One can tell if it is hard or soft sectored by the
controller card. The hard sectored has a uart ( or usart )
chip and the soft sectored has one of the typical
FD controller chips. I think it may have been a Western
Digital that they used.
 The other problem is that CPM requires RAM at the
lower addresses. You'll need to make the modification
that allows one to shadow the ROM. I suspect that it
is either on this groups archives or you might look
in the news group comp.os.cpm. I've seen it talked
about someplace.
Dwight
Received on Wed Feb 12 2003 - 21:33:01 GMT