At 04:55 AM 4/12/02 -0400, you wrote:
This is the information I have managed to gather on the HP IPC:
First have a look at the definitive guide to the IPC
Apart from that, I have managed to find the following info by playing
with my IPC:
There is a ROM at the back behind a little door. This contains basically
the Unix OS (HP UX) and at least in my case Tech Basic.
The ROM in the back is optional. The IPC had a very limited set of HP-UX built-in but
you could get a complete HP-UX in ROM (the Software Engineering ROM) and install it in an
expansion slot or you could get Technical BASIC in ROM. It installed inside the OS ROM
located under the backdoor. You could also get a blank PROM card to install your own
software. The same socket was also used for the Service ROM. Technical BASIC and the
complete HP-UX were also available on disk.
Tech Basic looks
surprisingly like Series 80 Basic (e.g the Basic on the
HP-86 and 87)
That's because the IPC was the designated replacement for the HP-85 series. BUT if
you look at the number range and accuracy, it's not nearly as good as the 85.
including many ROM additions (e.g. IO ROM).
The funny connector on the back (like a small centronics connector) is
HP-IB (the HP name for IEEE-488) which is used to connect peripherals
like floppies and hard disks. The IPC talks CS/80 over HP-IB so it
supports "modern" HP-IB peripherals like the 9122 floppy drive.
Correct. You could also get a expansion card that had a faster HP-IB port.
The IPC also has in internal HP-IL bus (a two wire, low power version of
HP-IB) which is used to talk to the built in printer. At this stage
I haven't managed to investigate whether I can externalize this bus
and connect additional peripherals.
I haven't tried that. Let me know what you find out about it. There was also a
HP-IL expansion card available for the IPC. I've used one to talk to a HP 3468 meter.
The built-in printer takes hp92261a print cartridges which (amazingly)
are still available from major mail order firms (e.g. www.staples.com
in the US, but I suppose you can get them in the UK as well). Since the
print cartridge contains the print head as well, it is very probable
that you can get the printer to work with little effort.
Those are the same cartridges that are used in the HP ThinkJet printers. They're
also used in some Canon printers and in Diconix printers. Just don't leave them in
for a long period of time or they'll leak all over the place. Also NEVER ship the IPC
or a printer with them installed, the changing air pressure will cause them to pump the
The IPC site (see URL earlier on) has a number of diskette images.
These are for double sided double density (720K) disks. I have
been unable to get any modern PC to write compatible floppies
using the standard double sided quad density drive (1.44Mb). I did
find a 720K drive on eBay and bought a pack of 720K diskettes.
Using OpenBSD on a PC I then proceeded to successfully transfer the
images to the floppies and access the data from the IPC.
BTW the IPC utilities in the IPC site (programs that can be used
to read IPC floppies on a Unix host) work only on big-endian
machines. You cannot use them on a i386.
Before trying to use the built-in floppy drive, note the following:
a) its totally non-standard. The connector is wrong and the RPM
is wrong. I believe there is no way that you can use a PC compatible
drive on that machine. So take good care of it!
Correct. Tony Duell can tell you lots more of the technical details about the drive but
it's basicly the same drive that HP uses in most of their 80s ish 3.5" floppy
drives; 9133, 9122, 9123, etc.
b) the heads need cleaning and the loading mechanism needs lubricating.
If you haven't done this already, do NOT skip this step, you may
damage the disk heads if you try to use a drive with a sticky loading
mechanism. See later on for cleaning instructions.
That's a COMMON problem with HP's double sided 3.5" floppy drives. The
discussion and cleaning instructions have been posted here several times.
c) The built-in disk notifies the OS when a new diskette is inserted
so that it is automatically mounted. This makes the built in floppy
more convenient than external devices.
It's a real pain to make the IPC realize that you've changed the disk in an
Using the system:
Just power it up and you should see the unix boot messages. Finally you
see the desktop manager (PAM). You can type paths on the command line on
top or use the cursor keys to navigate the file system. If you have an
HP-HIL mouse so much the better you just point and click.
You should find the BASIC interpreter in /rom/basic. Until you get
the floppies from Peter's site, BASIC is the only way to use the machine.
MASS STORAGE IS path
to change your working directory and
to list directories.
If you need documentation on Tech BASIC, I suggest you buy an HP-86/87
Owner's manual on eBay. They are close to the real thing and far more common
than IPC manuals.
The HP 9000 series manuals are helpfull if you don't have IPC manuals. They explain
things like MSI and other topics that you MUST understand in order to use the IPC. I
haven't compared the BASIC implementations in each but I expect that they're
For a hint on how to use external peripherals check the file
/documents/hp71_xfer on the IPC_BASIC_Bonus diskette.
As an example, here is a program that collects readings from an
HP multimeter (HP-IB device 13).
100 ! load HP-IB driver
110 MASS STORAGE IS "/dev"
120 ! on Series 80 the HP-IB card is always number 7
130 ASSIGN 7 TO "hpib"
140 ! The 13th HP-IB device is therefore 713
160 ! switch multimeter to remote control
170 REMOTE m
180 ! program multimeter for resistance, auto zero and trigger mode
190 OUTPUT m; "F3R1Z1T2"
200 ! initialize "previous" reading
215 DISP "Ready: press STOP to terminate program"
220 ! do while true
230 TRIGGER m
240 ENTER m; S$
250 ! display value only if different from earlier reading
260 IF v0<>v THEN DISP v
280 GOTO 220
Get a torx #10 screwdriver, almost all the screws on the IPC are
of this type so there is no point in trying to do any maintenance
The plastic diskette eject button seen from the front of the machine,
is not attached to the drive and is likely to fall off when you
remove the drive. It is best to secure it in place by covering it
with a small piece of adhesive tape. This will keep it in place
during the removal and subsequent installation of the diskette
First remove the back panel. You do NOT need to remove the system ROM
to do this, so leave it alone. The panel is held by just two screws
(probably the only screws that need a flat blade screwdriver) and hinges
on the bottom of the machine. Once the panel is removed you can see
the inside of the machine. A big PCB to the left and the floppy to the
Open the printer door (on the top of the machine) and look at the bottom
of the storage compartment next to the printer. You should see two black
screws. Remove them. Now the only screw holding the diskette assembly
is on screw on the bottom of the assembly (right on top of the PSU).
remove the connectors and the last screw. The floppy should slide out
Looking at the the floppy assembly you see a mounting bracket and a
full height floppy. Before removing the drive from the mounting
bracket mark the orientation of the floppy drive against the bracket
with a pencil this will make reassembly easier. Remove the mounting
bracket and the metal cover of the floppy. Do not forget to remove
a black screw on the back of the floppy, otherwise you will not be
able to slide the metal cover out. You should see the loading
mechanism on the sides of the floppy. Try inserting a diskette to
see how it causes the loading tray to slide along paths on the fixed
sides of the drive. These are the only parts that need cleaning and
oiling. Use machine lubricating oil (under no circumstances should
you use stuff like WD-40). Apply one or two drops on each side and
insert/remove the floppy until it slides in and out effortlessly.
I use a cleaning floppy to clean the heads, so there is nothing more
to do at this stage other than closely inspect the READ/WRITE heads.
Hopefully they should have the obvious orientation that allows them
to come into contact with the magnetic surface of the floppy. If
this is so, then you are in luck, otherwise you lose.
Replace the cover and secure the floppy on the mounting bracket. Orient
the drive and bracket so that the two screw holes are on top and slide
the entire assembly inside the IPC. Attach the top two screws and the
bottom screw. You may need to slightly adjust the drive mounting assembly
to align the bottom screw. Replace the power and data cables and
reattack the back panel. Remove the piece of adhesive tape securing
the eject button and you are ready.
Corrections or additions are always welcome.
Somewhere I've got a write up about the IPC. I'll try to find it and post it on
the list. (Found it. I'll post it at the same time that I post this.)