HP-207 – Part 3: A Historically Significant Piece

I discovered it later in the revival process, but the HP-207 (or Integral PC – IPC) I received for my B-Day has a historical significance. Indeed, my wife found this unit in Oregon. This detail has its importance since the IPC was the only HP computer designed in Corvallis. The second clue was the serial number of the machine: PP1 095 (note that many internal parts are marked with this number). It turns out that this IPC is a production prototype. I can only suppose that it is the 95th unit of the first spin. While I was sanitizing the unit (see part 2), I had to give special attention to the floppy drive – which was completely jammed/locked. Doing so, I found some really amazing information. Now I understand the signification of the markings I found on the case. But before digging into these details, let me quickly say that if you have the chance to find an IPC, please do not jump on your pliers and extract by force the floppy that is stuck in the drive (a simple density SONY model – 170 KB formatted).




You would simply destroy the R/W heads. Instead, you must remove the unit from the back of the computer and proceed with care while extracting the disk. Once the disk is removed, you can safely proceed and remove in particular the old and dried-out grease, clean-up the and re-grease all the mechanical parts. Normally, you should be able to insert and remove a test floppy disk with almost no force.


It is during this process that I could date accurately the manufacturing date of my HP-207 and I could precisely learn what it was used for during the IPC’s development. Indeed, an aluminum shield held several test notes – likely written by the technicians/engineers performing shock tests (and of course, I kept them ;-)). We can learn this way that the unit faced search errors and the drive’s bottom head holder was broken off during chock tests (chocks of 40 to 100Gs – likely during 3ms – performed on 4/26/1984). Finally, we can also link this information back to the Portable Computes episode of the Computer Chronicles originally broadcasted in 1985 (https://archive.org/details/CC214_portable_computers).



At 20:58 in the video, you can hear Srini Nageshwar (Retail Marketing Manager of Hewlett-Packard) say: “…so these machines have to put up a lot of vibrations. Like our machine can take a 100Gs on six sides.”. Voilà! The circle is complete. We have closed the loop between a marketing claim to the engineering tests used to back it! Enjoy the pics and Happy new year 2016!