When I share with you here about Hewlett-Packard vintage products, it is almost exclusively about programmable scientific calculators. But HP did many remarkable computers as well over the decades. For example, I presented the HP-207, a.k.a. the Integral PC (IPC), a few years ago (here). An amazing luggable personal computer, running HP-UX UNIX from ROM and packing in a luggable form factor, a yellow ELD, an inkjet printer, and a floppy drive, A true beauty!

Speaking of which, if you have not seen Chuck McCord‘s HHC 2021 presentation “The HP 9808A/B Unicorn – The Product that Almost Was”, know that it is worth the 30 minutes of your time to learn about what could have been the successor of the IPC, and why HP sabotaged it (@24:15). The cherry on the cake, during the Q&A session, you can hear a joke describing HP’s marketing skills (@27:15): “If HP sold sushi, they’d marketed it as cold, raw dead fish that could kill you if improperly prepared.” Funny.

But the HP personal computer I will share about today belongs to the 80 series, the precursors of the IPC. These iconic computers from the ’80s were all the rage in the engineering and scientific community. My first ones were given to me by a friend from a computer lab of the Paris VI Pierre et Marie Curie University. Since, I acquired several models: HP-85A/B, HP-86, and HP-87. I only miss the HP-83 and HP-87XM – and the industrial rack-mount versions. Just think about it. Suppose you could afford it (~$3,500), with the HP-85, you got a compact desktop computer with a high-res graphic CRT, expandable by design, booting into a solid BASIC (32KB), and a potent scientific calculator via a full-screen editor. Each model in the family has its specificities, but the HP-85 is the iconic model, with its integrated tape drive and a printer.

I mentioned earlier that the series 80 was expandable by design. Indeed, at the rear of these computers, the user has four expansion slots available to plug in various modules. In particular, extra RAM (from 16 KB to 128 KB) and ROM drawers with six ROM modules max per drawer. By choosing the right ROM, the user could adapt the features of the computer to its use. Need matrix multiplications? Use the Matrix 1 and/or 2 ROMs. Need to write low-level applications? Use the Assemble ROM. Need additional BASIC features? Use the Programming and Advanced Programming ROMs. The extension cartridges can also add niche capabilities: speech synthesizer, CP/M, FORTH, GPIO, BCD; you name it.

Like most vintage HP computers, the build quality of these machines is extraordinary. Which makes them reliable and a safe bet if you want to buy one. One caveat, though: the tape drive of the HP-85 is almost always failing as the capstan’s rubber coating is melting after four decades or so. A bit more on this later.   

Did I mention that the 80 series was the King of the science lab? Yeah, I did, which allows me to write about the I/O capabilities of these computers. With HP systems, I/O means HP-IB (IEEE 488 or General-Purpose Interface Bus (GPIB)). This efficient and versatile communications bus was very successful with lab and industrial equipment makers. Even these days, you can find instruments using this interface to control them. One can even find HP-IB to USB active adapters at a reasonable price. Depending on your HP model, either it has a built-in HP-IB interface (HP-87/86), or one can be added via an expansion cartridge. In addition to driving your spectrometer or another obscure instrument, HP-IB gives access to external mass storage devices such floppies or hard drives (if you can find and afford them). But, be aware, my experience with these antique mass storages is the opposite of the one with the central units: none of them works!

My preferred model in the 80 series is the HP-87, with no dice. I like this model because it doesn’t come with the failing tape drive and printer but has a double-wide CRT, more base memory (especially the XM version), and a standard HP-IB interface. I love it so much that it sits on my desk. But there is a big but: I always struggled to exchange data and programs quickly with a PC, an essential task any retro computer aficionado wants to do.

And this is true, regardless of the model you use; indeed, traditional solutions don’t work with these computers. For example, even if you can transfer a program as an ASCII string via a serial interface – you need the suitable module –, without the software that makes the BASIC interpreter tokenize the string, it is a pretty useless feat. I suppose the software used with the serial interface module can perform such translation, but it is a catch-22 since you only have access to BASIC after booting the machine.

This issue was real before the availability of Everything but The Kitchen Sink (EBTKS). Haaaaaaa, a true epiphany. EBTKS is a board designed by Philip Freidin, Russell Bull, and Everett Kaser that inserts into one of the four expansion slots. Power on the HP, and it boots into EBTKS, giving you immediate access to the 16 GB SD card to read and write your data and code. And loading stuff on the SD card is a trivial task with a PC. But wait, as the name EBTKS lets us guess, it does way more! But first, go check it out here. Note that the project started as a replacement for the defunct tape drives of the HP-85. Lucky us, it went above and beyond this initial goal. Among the fantastic goodies EBTKS provides to HP 80 series users, we can list: tape drive, floppy, and hard drive emulations, extra memory (up to 256 KB), 70 new commands (such as PEEK, POKE, or BOOT), a battery-backed clock, humongous storage, and of course, the possibility to carry *all* the ROM images available on the web (pre-loaded with 18 – not all ROMs can be active at the same time). The team is working on additional features. I am impatient to use the HELP feature, as HP commands can be cryptic.

When you order an EBTKS, you have to provide details on the system you plan to use, its configuration, etc. This way, it is shipped to you pre-configured, ready to use. A fantastic touch and customer service because creating a configuration file from scratch is not a trivial task. Instead, we just have to insert the EBTKS and flip the power switch. Et voilà! By default, it comes with emulations for four floppies – packed with programs – and a 5MB hard drive. It is a pure delight when it comes to saving and loading programs.

Even though you cannot use all the ROMs simultaneously, having them available via EBTKS is pure gold to an HP-87 user. For the anecdote, because the HP-83/85 ROMs are incompatible with the 86/87 and vice-versa, HP made it very clear using a different color to print the name on the modules. White for 83/85 and orange for the 86/87. As a result, when I searched rare ROMs – not the printer or storage ones –like Pavlov’s dog, I started drooling as soon I spotted an orange ROM in an online listing. I can detox now, thanks to EBTKS.

If you want to discover the 80 series without selling a kidney, you can find a few emulators online. I didn’t use them extensively; I installed and tried their essential feature. So, I cannot vouch for their qualities, besides their merit of existing. You can find an HP-85 emulator for Windows by Everrett Kaser here. Not an emulator per se, but you can learn about an FPGA implementation of an HP-85 and HP-86 here. You’ll find on the olivier2smet website many more emulators.

As usual, I will close with several press clippings for your convenience. I enjoy reading articles and advertisements published when the systems hit the market. So, if you are like me, enjoy and have a great weekend.