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Re: OT: Humor

tfreeman intel digichem net wrote:
> <<sigh>> The old H89 running cp/m. Never did get around to trying H-DOS or 
> whatever it was called, although I think it was pretty advanced for 
> running on Z80. If configged properly, as I recall, you could run 1 5.25 
> disk internal, two more 5.25 disks external, a 5 meg external hard drive 
> (I think it was 5 meg although it was about 8 inches across), and I 
> _think_ you could even get an external pair of 8 inch floppy drives with 
> something like 256K capacity.
Yes, it could have a pair of 8" floppy drives. I had one of the
external boxes with the 2 8" drives up until 2 or 3 years ago.

I also had an interesting S-100 drive controller from another
company. (I forget the name.) It would control 4 5.25", 4 8" and
by using a daughter board, 4 MFM hard drives. It would also support
a memory drive using extended addressing static RAM. It would do DMA
transfer between memory pages, or from its disk buffer to RAM. It
would read the entire track of a floppy in one pass. It also did
deblocking from the drive sectors to the 128 byte blocks CP/M
used. It could also handle double density double sided drives. I
even had a 3.5" drive attached to it, and could read/write 720k
DOS disks on a CP/M system. You could also read/write 360K DOS
disks on 5.25 disks. But it would not handle HD 1.2M disks. I
was thinking of making a hardware/firmware change to use the data
clock setting for 8" drives with 5.25" HD drives. Then I could have
read HD disks. All the hardware was there for it, but who ever
designed the board didn't provide implement it.


  Do not meddle in the affairs of dragons,
for thou art crunchy and taste good with Ketchup!

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