[sebhc] 64K memory

Lee Hart leeahart at earthlink.net
Mon May 17 10:34:34 CDT 2004

Dave Dunfield wrote:
> >I have the Heath H47 documentation. I can copy it if anyone needs it.
> >Briefly, the States are:
> ...
> >There's lots more about the individual bit assignments etc. but this
> >should give you the general idea. This is a pretty high-level format,
> >with very little that needs to be done by the H8/H89 itself.
> This looks like it would be dead easy to throw into the emulator.
> What I would need is:
>   - Detailed documentation on the commands
>   - Binary dump of the ROM
>   - A bootable disk image for testing.
> Anyone want me to persue this?

Dave, I'd be happy to photocopy what I have and send it to you. Just
send me your address (privately, if you like).

However, I never really liked the H47. It was cheaply madel, and
unreliable (what kind of nitwit makes an 8" disk drive out of molded
plastic and sheet metal). They were single-sourced, so when it broke,
that was the end of the line.

I would think that one of the other options mentioned earlier would be
preferable. For example, using the H8's RS-232 or cassette serial ports
to communicate with the PC.

Longer term, I am attracted to the idea of making a proper disk
controller board for the H8. Since the old WD1797 chips are so scarce,
and Heath already (sort of) supported SCSI with the H67, maybe the way
to do this is by implementing a SCSI board, which could plug into a hard
drive from an old Mac or PC, or a 1.44meg floppy drive from a Mac (they
were SCSI), or even a PC with SCSI card (two SCSI devices can exchange
data directly).
"Never doubt that a small group of committed people can change the
world. Indeed, it's the only thing that ever has!" -- Margaret Meade
Lee A. Hart  814 8th Ave N  Sartell MN 56377  leeahart_at_earthlink.net

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