HP IPC (update)

From: Wayne M. Smith <wmsmith_at_earthlink.net>
Date: Mon Jun 17 00:10:03 2002

Thanks for this excellent trove of info.

-W

----- Original Message -----
From: "Vassilis Prevelakis" <vp_at_mcs.drexel.edu>
To: <classiccmp_at_classiccmp.org>
Sent: Friday, April 12, 2002 1:55 AM
Subject: HP IPC (update)


>
> This is the information I have managed to gather on the HP IPC:
>
> First have a look at the definitive guide to the IPC
> (http://www.coho.org/~pete/IPC/integral.html)
>
> 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. Tech Basic looks
> surprisingly like Series 80 Basic (e.g the Basic on the HP-86 and 87)
> 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.
>
> 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.
>
> 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.
>
> 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!
>
> 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.
>
> 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.
>
> 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.
>
> Use
> MASS STORAGE IS path
> 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.
>
> 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
> drive.
>
> 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
> right.
>
> 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.
>
> **vp
>
Received on Mon Jun 17 2002 - 00:10:03 BST

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