Welcome to the my Emu75/DOS page !

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This page is focusing on the Emu75/DOS emulator, a ‘new-old-emulator’ in the sense that it is based on the same framework than my 20-years-old Emu41 and Emu71/DOS emulators and thus is a 16-bit DOS application – quite unusual for a new software on 2017.
Emu75/DOS, my collection of classic HP-IL controller emulators is completed, at last.

The name ‘Emu75/DOS’ is used to distinguish this emulator from a possible future HP75 emulator for Windows.



Emu75/DOS presentation:

Emu75/DOS is a software emulator of the HP-75C machine and HP-IL system.
It runs under DOS or in a command box under various 32-bit Windows (98,2000,XP,...).
It can run on 64-bit OS using a virtual DOS environment (see below).

Note: in all this document, Emu75 means “Emu75/DOS”.

Main features:

What's new?

Emu75 Documentation (pdf file)

Emu75 1.33 Freeware Package without ROM images – May 2022

Emu75 Source Files released under GNU Public Licence

Emu75 uses ROM images of HP-75C ROM and modules (Math, I/O ROM, ...).

To help you to quick start Emu75, you will find here the necessary images of the HP-75C machine. Although I don't have a formal authorization from the Hewlett-Packard company, I considered that this is consistent with the publication by HP of the source listings of these ROM. If it happens that the Hewlett-Packard company should be opposed to this, I would immediately remove these files from my site. Don't ask me to provide other HP or third party ROM images.

Running Emu75/DOS on 32-bit Windows systems

Emu75/DOS runs fine in the Command box on 32-bit Windows system.
On some Windows OS versions, the keyboard localisation is no properly configured when running 16-bit DOS programs – for instance on my French Win7 machine, the keyboard is responding as QWERTY instead of AZERTY inside Emu75.
To solve this problem, use the kb16 command (present in the Windows System32 folder), for instance "kb16 fr" for a French keyboard. You can add the kb16 command in a batch file, or add it to the autoexec.nt file (also in the Windows System32 folder).
It may also be needed to switch to the EN keyboard layout (Shift-Alt) to have access to the Alt-Gr characters.

Running Emu75/DOS on 64-bit Windows systems

Since most bare 64-bit Windows OS versions don’t support 16-bit DOS applications anymore, a virtual environment must be used.

DOSBox version 0.74 has been successfully used to run Emu75/DOS on a Win10-64 bit system.

This DOS Utility (author unknown) can be used to expand the DOSBox window from 25 lines to 50 lines (or 40/66 lines, at your option). Extract the 8x12_50.com (or other settings) and 8x12.fnt to your working folder.

I personally renamed the 8x12_50.com command to mode50.com for easy typing at each new DOSBox session.

Emu75/DOS and the PIL-Box

Emu75/DOS includes a native support of the PIL-Box, which works “reasonably” well on native DOS, Win98 or Win2K systems.
These systems are now obsolete and Emu75/DOS has to run in a virtual DOS environment on modern 64-bit OS, making this native support no more effective.

I now recommend to use the ILPer software in conjunction with the PIL-Box as a gateway between Emu75/DOS and a real HP-75C/D for program/data exchange.
This is done by sharing the same virtual drive HDRIVE1.DAT in Emu75/DOS and ILPer.

LIF archive files

LIF archives can be found on the Web. Here are my personal HP75 software collection (no doc, sorry):


Here are two volumes from the HPCC library with HP75 resources (again, no doc):


To use an archive, unpack it to put the LIF file image (size should be about 630K) to some directory, and declare the path to this file in HDRIVE1 or HDRIVE2 declaration (Emu75.ini file). Example: HDRIVE2 hp75_2.lif

You can find other archives, including the CHHU and SWAP collection, at The Museum of HP Calculators FTP and on the Joseph Horn Online LIF Disk Project.

HP75 system technical documents:

I used these documents a lot during the design and debugging of Emu75:


A lot of internal technical documents can be found on the HP-75 group page.


Reversi game

Reversi is a classic board game. The HP-75C version below is based on an adaptation of a HP-85 program I made for the HP-71B around 1985, with minor changes for Emu71 done in 2003, and adapted again for Emu75 in 2017.
It runs great on my Emu75/DOS in a 43- or 50-line mode command box on my old Win2k system, or in DOSBox in 40-line mode (or better). The screen size is too small to run it in Emu75/DOS in a normal 25-line mode.

              Reversi on Emu75/DOS


Reversi program for the HP-75C on a LIF disk image


The original HP-85 game and documentation can be found here: http://www.series80.org/Programs/HP85-GamesPac/index.html



Some links

General links about old HP calc.


More specific links about the HP-75C and HP-80 series


Emulators and simulators of HP calculators/computers, related to the HP75



J-F Garnier, 2022