HP IPC (update)

From: Joe <rigdonj_at_cfl.rr.com>
Date: Fri Apr 12 08:45:41 2002

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 ink out.

>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 external drive!

>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.
>to change your working directory and
> CAT path
>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 close.

>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
>150 m=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
>210 v0=-1
>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
>270 v0=v
>280 GOTO 220
>Drive removal:
>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
>without one.
>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
>towards you.
>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.)

Received on Fri Apr 12 2002 - 08:45:41 BST

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