Tag Archives: hp-85b

Hewlett Packard HP-85B: a marvelous desktop computer revived

At its time, the HP-80 series of computers were really desirable and expensive computers, mainly intended for control of test equipment and associated calculations. There is a screen, a printer, a tape storage device, all in one case.

For its age, still looking great!

Some cleaning of the CRT, and some other parts of the electronics to remove dust. But no other repairs were needed to the electronics.

All the shielding, all the parts, it seems to have been hand-assembled in small series, with each part individually checked and hand-labeled…

Only trouble is with some stuck keys. These can be operated, but don’t spring back easily.

Unfortunately, a common problem that can’t be fixed easily. Reason is the age, fatigue of the plastic. So I just switched the few broken keys with less-used characters. This is easily done by pulling on the white actuators firmly.

Surely, the HP-85B had quite severally limited memory, and there were many programs available that would need to be purchased piecewise, but thanks to great enthusiasts (google: EBTKS), there is a solution: the EBTKS extension board will provide huge additional memory, mass storage, and a replacement of the tape drive.

A little test program, to set the time, date (no year 2000 problem…), and even the printer still works (just needed a little cleaning).

The paper is thermal paper, but easy to read and can be even used to print simple matrix graphics.