On Wed, May 12, 2004 at 04:00:04PM -0400, der Mouse wrote:
> I'd also particularly like to hear of HP-IB disks of nontrivial digital
> size and reasonably small physical size...
The only HPIB disks I have _are_ of trivial digital size and _non_
trivial physical size - Commodore D9060 and D9090 units (5MB and 7.5MB,
5.25"-full height MFM drives inside). I keep thinking of trying to
rewrite the ROM code and turn the software-driven SASI port into a
SCSI port. One limitation, naturally, is the filesystem - it tops
out at around 16MB (it manages cylinder, head and sectors internally
as bytes - the "normal" geometry is something like 153 x 4|6 x 32).
One could re-write the filesystem, since I am not aware of any PET
apps that accessed the drive on a track/sector basis, unlike lots of
floppy programs, but that's a whole lot more work than implementing
a larger drive as N units of 255x255x255 sectors of 256 bytes.
What probably makes more sense, naturally, is to not attempt to
make the drive handle larger disks internally, but rather to make
a D9060/D9090 _compatible_ drive, with a subset of C= DOS 3.0,
using all modern technology, down to either a modern hard drive,
or perhaps a CF card. All you'd really need for that is your
favorite uP with an IEEE-488 interface, and a few megs of local
storage.
I haven't played much with HP IEEE-488 devices... where would I
find the command set (i.e. what strings to send the drive
over the GPIB bus) for mass storage? The other device I'm
curious about is a 9-track HP drive I have, but that can wait
until I'm home and have it in front of me...
-ethan
--
Ethan Dicks, A-130-S Current South Pole Weather at 12-May-2004 22:36 Z
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Ethan.Dicks_at_amanda.spole.gov http://penguincentral.com/penguincentral.html
Received on Wed May 12 2004 - 17:58:53 BST