Some Material Related to Historic Hewlett Packard Calculators and Computers

Most of the now classic Hewlett Packard pocket calculators and mini computers were technically advanced devices. In the 1970s and 1980s they were very popular among students, scientists, engineers and technically minded people. While not cheap, they combined excellent technology and high manufacturing quality with robust design.

This and the linked pages contain some bits of information which I have collected and also made available via the larger web sites dealing with HP calculators.

It is not my intention to start another site about HP computers. You can find sites with an exhaustive wealth of information easily on the web by searching for terms like "HP Museum" etc. Some of them also offer CDs and DVDs with collected material which are highly recommended.

My main areas of interest are centered around the years 1970-1990


German Literature for Hewlett Packard 41/71/80 Computers

Here, you can find a complete collection of the nine books in PDF format published by the Heldermann Verlag in the 1980s.
Note that the books are in German.


Deutsche Literatur für Hewlett Packard 41/71/80 Rechner

Hier finden Sie eine vollständige Sammlung der neun Bücher, die vom Heldermann Verlag in den 1980er Jahren veröffentlicht wurden.
Diese Bücher liegen in deutscher Sprache vor.


Some Write-ups from my Digital Scrapbook

(short PDF documents)

Making Your Own HP-IL Cable

Repairing a broken key on the HP 12C Platinum Calculator

HP Flexible Disk Formats

Using the HxC Floppy Emulator with HP Systems

The GET and LET functions in the Solver on HP Calculators

Plotting Curves at Constant Speed

Repairing a ThinkJet Printer's Ribbon Cable

Repairing a Transtec TT401 RS232 Terminal

Some TrueType fonts mimicking HP-71, 75, 85, 86/87 screen fonts

The HP-IB "SnifTer" Debugging and Display Tool for HP-IB

Some Notes on HP 9836 Repairs and Usage

Quick reference Guide to HP Portable Plus Escape Sequences

My Notes on using the HP 3396 Integrator

My Quick Reference Guide for the HP 3396 Integrator BASIC

Using a TTGO VGA32 board for Tektronix Graphics Emulation

Some of my own Quick Reference Cards

(written for my own purposes)

print out and fold or laminate.


HP-IB Devices

HP-IL Devices

Building a "Red Eye" receiver

Arduino Source Code

Explains how to build your own receiver to capture the print output of HP pocket calculators.

Reader Software Application for HP-41 Barcodes

Java software to read scanned barcodes and convert them or print program listings.

  Some Bits and Pieces for Sale

On this page I offer some difficult to obtain parts and accessories for HP-calculators and HP-computers. Note that this an offer for fellow enthusiasts and no commercial undertaking.

   Epson HX-20 and PX-8 related Information

I wrote down my learning experience with the HX-20 and PX-8 systems.

For these computers I also wrote a screen and disk drive simulator program which allows using a PC to connect to the HX-20 and to use the large screen of the PC for editing programs and outputting graphics.

In case of the PX-8 the simulator allows disk drive simulation and with the help of some BIOS extensions to send graphics and text to the screen.

Graphical System Extensions GSX-80 under CP/M 2.2

GSX was a device independent interface for text and graphics. While it became very popular in its GDOS/VDI implementation in GEM (especially for the Atari ST) it never caught on under CP/M-80.
I wrote a few drivers for my own purposes, which are made available here in form of compiled driver files as well as source code.

This document describes these drivers and lists properties of most of the existing GSX-80 drivers for CP/M 2.2.

Additionally, I wrote two libraries to use GSX with Fortran as well as some application programs

  • GLIB and GSXLIB libraries for Fortran
  • GPLOT plot program in Fortran, uses GLIB and GSXLIB
  • GEMVIEW Metafile viewer in Turbo Pascal

Finally, I disassembled  some existing drivers and the result is available here:


   3D printable Parts for old HP Computer Systems

This link points to my github repository where you can find some of my reproduction parts for HP computers, terminals and other devices.

These can be printed on a 3D-printer to make functional replacements of broken parts.

These models may be updated from time to time, so please do not copy them to other sites where I cannot track them.
You can use them for any non-commercial purposes.

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