Det virtuelle datamuseum / Regnecentralen / GIER Simulator


The GIER computer was built around 1960 by the Danish company, Regnecentralen.

I'm working on a simulator, making it possible to execute GIER programs on a PC.

The simulator is written in C, and developed in Linux to run under X11. A version for Windows is also available. The code is released as Open Source.

The latest version is available here (source and Windows binary): 20100713.exe (5.2 Mbytes)

Special version with larger control panels (only necessary, if you run Windows): 20100713large.exe (5.4 Mbytes)

Please note: You'll need some C programming experience to compile the source code under Linux.

Included are a lot of tapes containing the basic operating system, help-3, and a GIER ALGOL 4 compiler.

The versions 20041106 and later have a copy of the contents of the GIER machine at University of Aarhus. This was provided by Claus Hilberg.

The windows zip file is a self-extracting archive, created in Linux with zip and wiz from Info-zip. Store it on your disc (e.g. in c:\gier) as 20041106.exe, and double-click on it.

Under Linux, you can unpack the archive using the unzip command.

A special version has been made just for playing Nimbi on a Windows machine. Download and unpack nimbi.exe, change directory to where you've unpacked the two files, and start GIER.exe.

You can see a Javascript version of Piet Hein's Nimbi game here.

The Windows version has been made using MinGW.

The most important tool used during the writing of the simulator was a description of the GIER microcode. You can find this in the GIER documentation part of the virtual data museum.

I've written a short tutorial to get you started using this simulator.

Claus Hilberg has tested the speed of the GIER machine using the LINPACK test (rewritten in GIER ALGOL 4), and compared it to the list. The GIER (0.66 KFlops) is 54.010+9 times slower than the fastest machine today (November 2003: 35.86 TFlops). This is equivalent to a doubling of CPU speed every 13.5 month. The GIER ALGOL source code is available here, and the result here.

You can find more GIER software in our Software database.

Summary of changes:

  • 20100709 to 20100713:
    • The Linux version uses Pulse Audio.
    • Experimental: The main control panel has an extra lamp in the top row, between h and KLAR. This lights up when GIER waits for a drum transfer to finish.
  • 20070329 to 20100709:
    • Fix a problem in Motif version when a new .gier file is loaded: If the loading requires that the control board or nimbi board is destroyed the simulator would crash.
    • Corrected an error in my father's DEMON-5 program (LONGMULT).
  • 20070328 to 20070329:
    • New NIMBI board: Use computer-drawn board instead of image.
  • 20041106 to 20070328:
    • GIER can run in demo mode. See demo.txt
    • A NIMBI board is available. The code for playing NIMBI is included, this is written by Søren Lauesen. See here for a short introduction.
  • 20040906 to 20041106:
    • Stop sound before exit
    • Fix problem in SY; if you output a character, run for several hours, and print out another character, a signed counter would wrap around and become negative.
    • Fix typo in demon3.flx
    • Fix sound problem in Windows. Some sound cards would stop working, when the sample speed is set to 45000 Hz. The frequence has been changed into 44100 Hz.
  • 20021212 to 20040906:
    • DRUM_CELL_INTERVAL changed to match a drum speed test program. (Test program 8).
    • In typewriter input, pressing and releasing the shift button now generates a 60-58 sequence. Used by the help-3 edit program.
    • The GIER ALGOL II compiler is available; read gieralgolprototype.flx into HJÆLP by _l.
  • 20021006 to 20021212:
    • Support for buffer disk added
    • Config file with Aarhus GIER added (Claus Hilberg).
    • Support for plotter
  • 20020424 to 20021006:
    • Main control board shows bus status while running
    • Fix bug in buffer addressing when wrapping at 4096