Hewlett Packard HP9845b

Hewlet Packard HP9845b


The HP9845 series computers were introduced in 1977 as a continuation of the successful line of scientific and business calculators and computers from Hewlett Packard.  The HP9845 had many unique features and options.   The processors (actually it has two) are custom built 16bit chips from HP on a ceramic substrate, and operate in parallel.  One handles the language and the other handles the I/O functions. Options for the video display include monochrome ("B / T" model) and color graphics ("C" model).   For storage the B and C models have dual tape drives and there is a built-in thermal printer.  A complete history and specifications can be found on the hp9845 website: https://www.hp9845.net/9845/history/story/ .

I first worked on the HP9845 in 1980 on a project with a company that was trying to develop a PC board CAD program on this system.   I wasn't the programmer at that time, I worked on setting up the hardware which had the 9845C color graphics model and an HP plotter attached on a GPIB (HPIB) interface.

I was able to recover a 9845b model and various parts over the years and have been working on restoration.