[sebhc] h17 and h8d disk images

Dave Dunfield dave04a at dunfield.com
Wed Sep 1 19:38:35 CDT 2004

> The Z80 board didn't require the enhanced board. The older
>8080 machines required the extra board. I'm not
>sure if the CP/M boots to both the H8-4 and H8-5 boards. 
>I'll try to check this out. I most likely won't get to
>it before the weekend. I have both boards so I can try it.
>HDOS will boot to either board.

Barry mentioned that there might be a Lifeboat version orged
higher in memory - possibly it will work with the H5 and
standard CPU board (no RAM at zero) - if so, I would love to
get a copy.

Still - CP/M isn't really CP/M if it can't run programs at
$100 - so ideally, I would like to find a version which is
configured for H5 console I/O, and works with the RAM at zero
feature, but basically requires no other "special" features...
Does such an animal exist?

Does anyone know if CP/M just switches to RAM once, or does
it toggle between ROM and RAM (say to access ROM functions)?

My address space is a single 64K 8086 segment - to handle a
"real" switch, I would have to rewrite and slow down the accesses
to main memory in the CPU emulator (and there are a fair number).
If it only does it infrequently, I could get away with just copying
the RAM/ROM content in and out of the address space, and updating
my write protect table...

dave04a (at)    Dave Dunfield
dunfield (dot)  Firmware development services & tools: www.dunfield.com
com             Vintage computing equipment collector.

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