Mass storage for an 9825A
ard at p850ug1.demon.co.uk
Mon Apr 20 14:14:44 CDT 2009
> I am trying to get my 9825A to exchange programs, data with the
> outside world
> and I am not making any progress.
> The 9825A has a working tape drive, but as I only have Series 80 stuff
> (which use the same tapes, but different formats), this only allows me
> save/restore my own stuff.
> The 9825A also has an HP-IB interface (thats the only interface I've got
> for it), but I have trouble connecting a floppy drive to it as the mass
> storage ROM that supports HP-IB drives only works with the 9825T.
> I have the System ROM which allows ASCII programs to be"typed"
> from an external device, but I would like to be able to have access to
> the program collections available on floppy images (e.g. the files on
> the diagnostic tape).
> So any ideas - suggestions?
AFAIK the only mass storage device that the HP9825 supports 'out of the
box' is the internal tape drive. And the only floppy disk ROM that will
work on a 9825A is the older one that supports the 9885 8" drive only.
Maybe one of the following could be tried :
1) If you can get the older floppy disk ROM and a 9885 + 98032 interface,
then maybe you can somehow trander your disk images to 8" disks. But
finding that hardware is proably not easy
2) If you can get the ROM and the 98032 interface (the latter are _very_
common in my experience), then maybe you can get some other machine to
emulate the 9885. The phyisical interface is quite simple (16 data lines
each way, 2 control lines each way, stroe, acknowledge, etc), but AFAIK
the command protocol for the 9885 is not documented anywhere. There are
some clues in the bits of source listing in the _HP9000/200_ Pascal
manuals (on Bitsavers), but it'll take a lot of work to figure it out.
3) If your system programming ROM supports program entry from an HPIB
device, you might have some luck using a _Commodore_ disk drive (which is
internally file-orientated, unlike HP drives). Philip may have some more
hints on doing this. Of course this will be totally incompatible with
anything anyone else uses
4) Can you pick the program archives apart on another machine and turn
the programs into text? If so, it's then just (!) a matter of figuring
out some interface between that machine and the 9825. A 98032 (parallel)
or 98036 (RS232) interface would be useful, though.
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