-----Oorspronkelijk bericht-----
Van: cctalk-bounces at
classiccmp.org [mailto:cctalk-bounces at
classiccmp.org]
Namens Tony Duell
Verzonden: zondag 9 december 2012 22:23
Aan: cctalk at
classiccmp.org
Onderwerp: Piecing together an HP9880
I am not sure if this is on-topic since the machine involved was sold as a
calculaotr. On the other hand, it programs in BASIC, it's getting on for
40
yuears
old, and I am thinking of adding a hard disk. Classic
computer?
The HP9880 is the hard disk (14" platters) for the HP9830 'calculator'. I
am slowly
gathering the various bits of this system, I would
love to get it all
working again.
As I understnad it, you need :
An HP9830 calculator,
HP9866 printer
Mass Memory ROM module
HP11273B 'cable' from the HP9830 to the controller
HP11305 disk controller
HP11302 cable from the controlelr to the drive
HP7900A disk drive (one fixed, oen removeable plater) + PSU (or HP7901,
which
has only the removeable platter, but has an internal
PSU)
System tape cassette for the HP9830
Disk packs (of course).
Now, The 9830 and 9866 I have, working. The HP11305 controller and both
'cables' (I put that in quotes becase thes cable assembleis have PSBs
stuffed with
ICs at at elast one end -- the 11273 has over 50 ICs
in it) I also have,
untested,
but I know th PSU is good and the microcde ROMs look
OPK (the disassebmyl
of
the mcirocode makes sense). Since everything else is
standard TTL,
analogue or
RAMs ICs, I think that's reparaiable if necessary.
I have the scheamtics
and
micorocde source for all that.
The HP9800e emulator includes a dumo of the Mass Memory ROM, and thus I
have it in an EPROM module.
That emualtor also has an image of the ssytem and service tapes for the
9880,
but as yet I haven'tt figured out the format of
the image file or how to
get them
back onto physicl cassettes. I do have another tape
drive mechansim (not
HP)
which sould be able to produce compatible tapes
'Just'
a little matter of figuring out how ot interface it to soemthign and use
it. At
least
I ahve the handbook for said drive, it includes
timeing diagrams and
schematics.
Which leaves the drive and packs. This is the problem, I susepct I do
havev a
7900A. Alas it was in a skip (dumpster) and had a
2100A thrown on top of
it. The
2100A survived. THe 7900A is more sdubious. The front
was samaged when it
was gtaken out of the rack too. It's missing the terminator and the little
card
edge conenctor PCB, but those are easy to make I
think.
It's going ot need work. I also don't have the PSU for it. This seems ot
be
120C
AC (not isolated from the mains) for the blower and
spindle motros),
unregualted +/-24V and regulated +5V, +/-12V. Nothing difficult, but I can
see
myself speding time and moeny making something and
then find the heads
will
no logner fly. I susepct replacement heads are not
exactly common, I
wonder if
RK05 heads can me made ot fit?
According to the HP nanual for the drive, there was a text/service unti
for this
drive, it conencted ot the side of the backplane. I
cna't rememebr the
model
numebr (HP13219?). Hase anyone ever seen one, or have
the manuals for it?
And now for the pack. It's the same physicla size as the RK05 pack, but
24 (hard) sectors. Of coruse there's the fixed platter in the 7900A drive
with
it's
own 24 sector hard dsetoy rign nad transducer. I
belived the drive will
spin up
with any pack in it, so I could put a
'scratch' 12 sector RK05 in there to
(a) see if
the heads will fly and (b) see if I can use the fixed
paltter (which will
be 24 sector)
drom the HP9830.
If I get that far, I guess I then take an RK05 pack apart and attempt to
put
anotehr 12 notches i nthe sector ring. I beleive I
then have to re-centre
the
platter on the hub which will be
'interesting'
What if the heads crash? Maybe try to fit RK05 heads (I have some brand
new
spares here). Maybe try to interface an RK03 or RK05
to the HP contorller.
The
interface is differnet, but at least the data rate is
the same. It woudl
take a bit of
logic to get it to work, but... If all else fails,
make a solid-state
repalcement for
the drive?
I gueess the questions at the momnet are :
Anyone know the precise details of the tape image file format for 9800e?
Anyone ever manage to fit RK05 heads into an HP7900?
Anyone ever managed to cut the ectra sector notches?
Anything knwon about the disk service unit for the HP7900?
Does anyone have any comments/thoughts. Am I totally crazy for trying to
do
this?
-tony
If you want it I do have a copy of the system tape.
I also have the mass memory rom .
Let me know if they are of any use for you.
-Rik