HP Portable Plus – part I

Hewlett-Packard used to design and manufacture great systems. Today, I am pleased to share with you my experience with the HP-110 a.k.a. Portable Plus laptop. I bought this computer many years ago, as a second hand, and unearthed it recently. It was about time! This specific model was manufactured in America in 1989 (SN: 2903A33602, PN:45711FK (F=512 KB, no modem, K=English-International US). Sure, a 28 years old machine doesn’t qualify for CES 2017, but there are some things to learn here. First. the HP-110 is part of the 100 family that contains the HP-150 with its remarkable touchscreen technology (using infrared emitters/receives mounted in a frame around the screen) and the LX palmtops.

To me, it really fits between the HP-150 and the IPC I’ve presented last year (see the link to the first port of the series at the end of the post). An earlier version – the Portable – was launched in 1984. I needed to give all this ancestry information just to tell that the HP-110 is really a lab/field machine, even though it was targeting the traveling business users. While it had all the features and characteristics for a dream field machine, it had no chances against the laptops to still to come. Indeed, the machine is running MS-DOS 2.11 but is not a PC compatible. Therefore, to run on the HP-110, applications may need to be adapted.

Only a few PC BIOS services are supported, so if your app is hitting the BIOS or the video hardware, then it may fail miserably. In fact, only 17 IBM function calls are supported in the HP BIOS. But that’s not an issue for two reasons. First, the machine comes pre-loaded with communications and productivity applications in ROM (Lotus 1-2-3 and Microsoft Word just to quote the most important ones). And yes, HP aficionados, the PAM (Personal Applications Manager) is your default shell. Think about PAM as an integration layer sitting between the DOS and the applications. Second, this laptop has no floppy disk unit. Instead, the main memory –battery backed-up – can be partitioned between the main memory – available to applications – and a RAM or virtual disk. Unfortunately, with a limited amount of memory (let’s say somewhere between 128 and 256 KB), you need to be wise about this setting. However, the system is not a closed brick. Indeed, it can communicate either via the serial port or the optional modem (300 – 1200 bauds, not authorized in all countries). Last but not least, the unit comes with an HP-IL controller. HP-IL, if you are not familiar with it, is similar to today’s USB, where you can link together multiple devices arranged in a loop (interconnected via the HP-IL loop). This doesn’t come as a surprise, as with many HP computers of the era, the HP-110 was really at home in the lab, where your computer needs to talk to measurement devices and remote storage.

For the anecdote, HP sold a battery-operated floppy disk drive that could be used in the field via HP-IL. For the Portable, HP used the same expansion drawer approach that made the success of its HP-80 family computers – I will need to present here these marvels someday. The HP-110 has two of these drawers. One for the ROM modules (12 slots total) and one for the RAM (and expansions). The ROM drawer has empty spots, and nothing should prevent one to pick a compatible application and burn it into an EEPROM to use it with the HP-110. The other characteristics of the system are as follows: Harris 80C86 CPU @ 5.33 MHz, 128 KB CMOS RAM, 192 KB CMOS ROM. The display is a non-backlit monochrome LCD – with a non-PC resolution of 16 x 80 characters (480 x 128 pixels). The screen contrast can be adjusted and is pleasant to use. Unfortunately, it is pretty hard to take quality pictures of it. So please do not judge the machine by the poor quality of my screen photos/videos.

The HP BIOS allows applications to perform text operations in graphics mode and had the support of HP Roman-8, a richer alternative to ASCII. An aftermarket option could be used to add a back-lit but at the expense of the battery life. Speaking of which, the HP-110 is a beast (33 x 25.4 x 7.3 cm), weighing only 4 kg (8.5 pounds)! Part of this weight is the SLA (Sealed Lead Acid) battery. Fully charged, it can power the HP-110 for 20 hours! In sleep mode, the machine draws 285 uA vs. 125 mA powered. Note that the computer has advanced power saving features – which are pretty exceptional for the period. After 28 years, the battery of my system died. In a future post, I will show how I brought the machine back to life. Finally, I must stress again the exceptional quality of the documentation. In contrast, today’s machines’ documentation – if any –, is a pity! There is plenty of photos and videos for you to enjoy!

https://www.youtube.com/watch?v=NY7AR_xmcQ8 (there is an HP-110 at the beginning, and an IPC later on).

https://archive.org/details/bitsavers_hpportableblePLUSTechnicalReferenceManualAug1985_25919880