The Input Output board that was originally in the unit did not have PIO so it has been replaced with the spare card. This may allow the use of a parallel port printer.
Ports from left to right looking from the rear:
25 Pin Female D
Daisy Chain Serial Port on RS232 Buffer board. Do not use.
25 Pin Male D
Serial Port on RS232 Buffer Board. This sis connected to the 8251 on the Microcomputer Board. This port is the terminal connection for dumb terminal built into the monitor ROM and initiated with “t” at the monitor prompt. 9600, 8 bits, no parity. A null modem was required to connect to a PC.
25 Pin Female D
Serial Port on Datacon board. This board is connected to the SIO on the Input Output Board. Level shifting is done on the Input Output Board. 2400, 7 bits, odd parity. May be configured as the printer port.
25 Pin Female D
Parallel Port on Intercon Board. This is different from the original configuration which used a Concat Board. The Intercon Board is connected to PIO Port A on the Input Output Board. This may work with a parallel printer but without success so far.
System configuration is important to make these devices work.
The DIP switches on the I/O Board may have an effect. There is some info in the manuals, but it is patchy.
Virginal system disks seem to be absent so it is necessary to construct a couple based on my best guess of what was on them.
There seem to be two main categories of operating system: 64k and FAST. There are different versions of both. The FAST (File Access Storage & Transfer) uses the addition 32k above 64k to improve performance, eg by providing disk buffering.
The Checklist in the documentation is quite specific about the FAST files, so a disk has been prepared based on that list. RUN.COM could not be found.
The 64k version described in the manuals is version 8.3, but the coverage is not comprehensive. The constructed system disk is my best guess based on what is usually on a CP/M 2.2 disk. There are three different formatting programs.
Fresh disk images were created using a pair of goteks. This was mainly done for the FAST 2.22 operating system. A clean OS disk was created and the used as seed for various other disks including basic, wordstar, dbase etc. This was done using a pair of goteks running flashfloppy.
The new disks worked fine both as images and when written to floppy media, but it was not clear what speed flashfloppy would use for writing disks. Looking at the images in the HxC software it seemed that it was writing at 281rpm sometimes.
Just to be completely safe the images were written to floppy media on the machine and then re-imaged at 285rpm. These disks are numbered starting at 101.
The HP 150 is a remarkable machine that never fails to impress, even though commercially it did not do well. The computer itself includes the very sharp green monitor and makes provision for a printer as well.
It runs MS-DOS 2, but it is not an IBM compatible machine.
The most surprising features are the touch screen and program enhancements that use it. This was a significant investment by HP.
This machine was a FB marketplace purchase all the way from Bundaberg. The seller was the original owner. He purchased it back in the early eighties to support his surveying business. He said that he wanted a quality machine, and that meant HP.
If you look carefully, there’s a child’s sticker near the 150 at the bottom right of the monitor. Perhaps from a now adult child. I’ve left it there.
I knew it had a video RAM fault when i bought it and that took a little work to resolve. The disk drives are Sony single sided 3.5″ units – a very early adoption of this technology – that needed a good clean to operate. Apart from those issues, this machine was good to go.
This machine had been powered up recently, so a felt ok about switching it on. The power on self test had given an error code: 1040. I had grabbed the service manual and looked up this code before i purchased.
The Service Manual has info on interpreting the code and on the LED readout visible through the back panel.
1000 means keyboard or touchscreen problems.
0040 means a graphics RAM problem.
It took a couple of power cycles to get the error codes from the LEDs at the back of the unit. Each error has four nibbles that are shown one at a time.
The LEDs gave the following:
EC40: GRAM Travelling test failed
E840: GRAM Marching test failed
9120: Keyboard did not identify as being present.
Clearly, there were two quite separate problems. There were no batteries, so I expected 0001 error – but didn’t get it.
The Graphics RAM tests look like they have 512 slots. It has 512 horizontal resolution. 390 vertical. Curious number. The number might be a column or a row. (Other clues point to a column.)
The graphics card pulls out fairly easily from the “front plane”. As is often the case with card cages, it is almost impossible to instrument the card without an extender – which i don’t have.
The manual doesn’t go down to the chip level, but the error code looked like it might. Probably an error bit for each of the 8 bits of GRAM and 1 bit for the bank. That made it the 6th bit of bank 0.
I could see two bad vertical lines on the screen – one was flickering, and the other was solid. They were repeated across the screen. I wired up quite a wide ribbon with alternating signal and ground to bring the RAM outputs to a scope so I could check with the board in place. I found two lines that were different from the others – bit 6 on both banks.
I cut out the first RAM and replaced with a socket and 6164 DRAM. The 16k DRAMs are compatible with 6164 64kb DRAM. The error codes changed on the 9th bit – the second bank failure. I repeated the exercise and the GRAM errors were cleared.
The manual said that part of the GRAM was used for variables, so I was hopeful that clearing the fault might allow the machine to the boot stage. And it did. I had some work to do on the drives before i could try to boot.
The main processor board is fairly easy to remove from the “front plane”. It has a mezzanine RAM card RAM with 256k of memory.
Touch panel:
CRT, chassis, and power supply:
I didn’t see anything that particularly worried me.
The HP 150 uses an external 9121 2x Floppy Drive Unit that connects via HP-IB. The drives are Sony OA-D30V-1 3.5″ single-sided double-density 70 track units. HP was a very early adopter of the 3.5″ disk format.
The drives were quite gummed up. I cleaned and lubricated them, and they were good to go.
The unit came with several disks, but it wasn’t necessary to use them. There are lots of disk images available at the HP Museum:
The images are in either Teledisk or HPI format. I had limited success writing Teledisk images using Teledisk on a PC. Perhaps the drive wasn’t configured for double density disks.
I did better using HPdrive (also used with the HP 85). HPDrive uses HPI files rather than TD0. These seem to be similar to raw image files. The TD0 files were converted to HPI format using a utility, TD2HPI.
I found that the 9121 drive option seemed to not work very well. The 9122 supports double-sided disks and uses the SS-80 protocol rather than the Amigo protocol. Perhaps a little incompatibility in the amigo protocol.
HPDrive reported that all the images were the wrong size – perhaps because it’s a double side drive. They worked though.
Devices need to be configured using “Device_Config” on the system disk. The boot drive is fixed as HPIB address 0 drive 0. This is drive A:. For the 9121 unit, drive 1 is B:.
The HP150 can also use the 82901M drive unit that i use with the HP 85. I’ve set the 82901M drives at HPIB address 2. These are drives C: and D:.
The 82905B Printer is set to HPIB address 1.
The following creates a -9122 drive at HPIB address 3.
Hpdrive -l 3 -a 3 -9122 <filename>.hpi
The system disks use MS-DOS 2.01, but don’t have the full collection of programs that would normally come with the OS. There are rumours of an MS-DOS disk with some more commands, but I haven’t found one.
The disks need to be formatted before use, and that seems to be the only way to set the disk label – so you can’t just format a batch and label later.
Amongst the disk images on the museum site was a hard disk image with MS-DOS 3.2. I was able to boot from that and create an MS-DOS 3.2 boot disk with a few more programs.
To boot from the image, the hpdrive has to be at address 0 and the physical 9121 drive unit must be reconfigured to a different address. eg:
hpdrive -l 3 -a 0 -9134D 150loaded.hpi
The system needs to be completely restarted if the drive address is changed.
There is no way to copy a complete disk track by track.
It seems that distributed disks are “uninstalled”. There is an installation program on the Applications disk, that allows programs to be installed from the distribution disk on to a formatted floppy disk. The installation copies the files over and sets up files for the Personal Application Manager (PAM). This is a program which acts as a shell and activates programs by touching soft function keys.
Some of the disk images on the HP Computer Museum site seem to be installed and some not. Some of the disks don’t follow the HP 150 “formula” and just have software on disk that can be copied over.
In some cases, it seems to be possible to install from an “installed” disk, but in other cases it seems not. Generally it’s possible to copy over the files and they will work. They won’t appear in PAM, though. You have to go to the DOS command prompt to execute them.
HP seems to have used hidden files to manage copy control. The hidden files can be revealed with chkdsk /v but there seems to be no program on the system disk to unhide them.
This brings us to the subject of transferring files to and from the HP 150. The usual suspects are disappointing. Greaseweazle and FluxEngine don’t support the format but can read and write fluxes. Many of the HP formats can be manipulated by HPDir, but it seems that the HP 150 file system is quite different from the HP 9845 file system.
Both the HP 85 and the HP 150 have a curious disk layout where each track has 16x 256 byte sectors and 1x 128 byte sector. Others have commented that the 128 byte sector is not used.
There is an MS-DOS driver, HP150SYS, for IBM compatibles that allows manipulation of an HP 150 disk in much the same way as IBM disks. This driver was written by the author of Teledisk, Sydex. It works well.
Files can also be transferred over a serial line using Kermit. The disk image for Kermit is a 720kB image, but i could access it by setting the drive type on HPDrive to a double-sided disk unit. Then the files could be copied over to some single-sided disks.
I have an HP 7470A plotter that i originally bought to go with my HP-85 computer. It worked ok with the HP 85, but wasn’t fully supported by all the software because it was a serial model rather than the HP-IB version.
The HP 150 seemed happy to allocate the plotter to the second serial port and the manual for the HP 150 Graphics package had instructions for the HP 7470A on a serial port. It uses hardware handshaking – I tried without and it gave errors.
The instructions said to use an HP 13242G cable. The cable I had didn’t have enough conductors, so I made a cut-down version with just the signals supported by the plotter (see technical manual) and to give symmetry.
The formatting of the manual is a little messed up, but the HP 150 has to be set up just right. Go to MS-DOS command prompt. Once there, the machine can be put into the built-in configuration.
I stuck with 2400 baud for compatibility with my notes on the HP 85.
After a five-year wait, an HP-IB plotter finally came within reach. Mike at the ARC Group had got it as part of a job lot, and he generously gave it to me.
This is my second HP 7470A plotter – the other is the serial version. These plotters are very simple, two pen, paper-moving plotters. The serial interface supports operation with computers from many different manufacturers, whereas HP-IB is the native interface for the HP computers of the era.
There was just one problem with the new arrival: it had seen some weather.
With power off, the carriage would not budge and the papers wheels were similarly stuck fast. The carriage guide bar was quite corroded.
I could also see that some of the grip had come off the paper wheels and that the opposing rubber wheels had flat spots.
The machine was pretty filthy, so a full tear down seemed appropriate. I couldn’t find a service manual, so i used the force. I took a lot of photos as i pulled it apart.
One screw to release the carriage motor. It was still spinning freely, which was a good sign. The belt tensioner and wheel came loose at this point. They were put safely in a container with the spring.
With the carriage motor out of the way, the up/down solenoid mounting screw can be backed off and the pen up/down bar can be removed. The rubber belt can then be removed.
The paper motor has a flexible coupling like a universal joint. Once the axle clamp is backed off the motor can be removed. Then the solenoid can be disconnected and removed. The core just falls out.
The carriage guide can then be removed and then the carriage from the guide. The guide cleaned up very easily with some emery paper. Often rust looks much worse than it is, and it was certainly the case this time.
I didn’t fully disassemble the carriage. There are a couple of springs in there, so i just put the carriage in a takeaway container and sealed it down.
The main plastic chassis could then be unscrewed and removed.
After the springs were removed, the paper release mechanism came away fairly easily. Then the bearings could be released.
The bearings seemed to have seized but they turned out to be ok. They had just got a little glued with rust from the shaft. They are probably stainless steel.
I removed the rest of the “grip” from the wheels and wrapped them in some emery paper. We’ll see how that lasts. I could have cut it a little straighter, but i thought it was good enough against a rubber wheel.
I didn’t touch the mains wiring. It looked well protected. I did give the board a clean in spots, but i didn’t want to get any moisture into the buttons.
The button panel is aluminium and it had some oxidation. I just gave it a light rub with some scotchbrite.
Unassembled, the plotter took up a lot of space:
The case was filthy. I used jif and elbow grease to clean it up.
Having cleaned everything, and made sure that everything was moving ok, i put it all back together. I put a drop of oil on the carriage guide.
I set the DIP switches as per the manual, except i used A4.
The HP 150 had been set up to use the serial plotter. I changed this with the configuration program on the setup disk to HP-IB address=05.
Initially, the grip on the paper failed at the flat spots on the rubber wheels. I rounded them off with a file and then added some surgical tubing over them. They worked much better then.
The plot was produced with the Pie Chart software. The paper size has to be set correctly, otherwise the program complains that the plotter is not compatible.
Happy days. I’ll try it out on the HP 85 when i get a moment.
I’ve had an HP 9123 Dual DS DD 3.5″ Drive Unit sitting on a shelf for a couple of years. This drive unit was intended to operate with the HP 150 II rather than the HP 150, but i thought it might work ok with my older machine anyway.
Unlike the 9121 it does not include a power supply; it was intended to draw power from the host computer. Although it uses HP-IB to communicate with the computer, it uses a different protocol: SS80 instead of amigo. I was pretty sure that i had used SS80 on an emulated drive, so i figured that would not be a problem. I wasn’t sure what the computer would make of the double-sided disk drives.
In these situations, there is only one thing to do: suck it and see.
I started by ungumming the drives. The lubricant used on these old Sony drives seems to set like glue with enough time. IPA cleans it out pretty well. I re-lubed with some light oil.
The service manual indicated that the power requirements. This unit was the thirstier option.
I had a 5A 12V power brick, so i figured i could use a buck converter to make the required 5V. I found a suitably low cost converter, which turned out to be tiny. After buzzing out the supply lines, i made up a little adapter box, checked the voltages, and plugged it all in.
The unit fired up, spun the drives, exercised the head carriage and extinguished the self-test light as it should.
I set up the address to 04 and configured the HP 150 to use drives at that address. Initial accesses did not go well – lots of errors and a disturbing amount of noise.
I thought that i had cleaned the heads, but closer inspection with a dental mirror and bright light showed a couple of stubborn spots on the top heads. These were dragging on the disk surface, generating noise, and gouging the disks. IPA is the usual goto for head cleaning, but i find that sometimes some water/detergent on a cotton bud is more effective. Once the heads were spotless, things went a lot better.
I found that i could read and write disks that had been formatted as single-sided in the 9121 drive unit. I could not format disks on the 9133 – the HP 150 format program failed. I tried with MS-DOS 2.1 and MS-DOS 3.2.
I had a couple of close encounters with Sun workstations back in the early 90s. The first was with a mobile computer system used by the Royal Australian Navy to process laser depth sounding. Two Sparcstation 2 (i think) served as the graphical front ends for a MIPS rack mounted system.
The second was when my employer chose to use Mentor Graphics PCB design software, which ran on Sparcstation IPXs.
This one came up on Facebook marketplace quite early in my hobby back in 2019. I rediscovered the seller as a colleague, Daniel, at the Adelaide Retro Computer Group a year or so later.
The IPX 4/50 unit came with 64MB of memory and an internal 6GB SCSI drive with redhat 6.2 installed. It also came with a SCSI CDROM, an empty hard drive expansion unit, and an HP 2000 DC DAT tape drive and all the cables required to join them up.
I purchased another spare caddy CDROM unit from Daniel.
It came in pretty good condition and was able to boot Linux from its hard disk as long as the NVRAM parameter were punched in prior to boot. It was very slow with Linux 6.2 though.
The mouse is one of the optical units that requires a grid over a reflective surface. Daniel sent me a PDF of the grid for me to use to make a mouse mat.
It came with a video cable and adapter for use on a normal VGA screen. The Sun monitor shown above was an addition courtesy of Michael from the Adelaide Retro Computer Group, who saved it from recycling.
Although i’d used similar machines in the past, i have never been a Unix system administrator, so i expected to have some challenges.
Since setting up this machine, i have added an Ultra 5, a Enterprise 2, and an SGI Indy. I am still a very amateurish admin, but i know more than i used to.
