IBMulator is a free/libre, open source emulator for the IBM PS/1, able to run with the original ROM. The goal is to create a faithful emulation of the machine, complete of the characteristic 4-quadrant graphical user interface.
Currently IBMulator emulates only the PS/1 type 2011 with the 80286 CPU.
* Works with the original IBM ROM
* IBM's peculiar 4-quad GUI and BASIC programming environment included!
* PS/1 Audio Card emulation
* 8-bit DAC and a Programmable Sound Generator with 3 voices plus noise.
* HDD and floppy emulation
You can use standard floppy and HDD images in LBA format, created for example with the dd Linux command. The IBM's HDD 8-bit RLL interface is also emulated, so no additional IDE roms workarounds are needed.
* Realistic timings emulation.
The 286 10MHz CPU, the WDL-330P HDD, and the integrated VGA are as painfully slow as in the original, for the truest PS/1 experience. The Prefetch Queue is also emulated, so games like JetFighter work as expected.
* OpenGL video output with shaders.
The video output can be manipulated with standard GLSL shaders; included is the CRT shader by Timothy Lottes
* Emulation of the working noise generated by the floppy drive, the HDD, and the system unit.
* State recording and resuming.
* Runs in Linux and Windows, 64-bit only.
* Screenshots, audio WAV capture, and VGM dumping.
When an audio recording is started, music data from PS/1 and AdLib audio cards are also saved in VGM format.
* Full OpenGL GUI.
Triple mode of operation: compact, normal, and realistic, for an added sense of realism.
* Debugging tools.
* Multithreaded.
OpenGL rendering, CPU core, and sound generation are on separate threads, so your i7 multi-core beast has some spare cycles for overclocking that puny 286.
* Highly configurable.
You can create a dream PS/1 configuration, with 496MB HDD, 16MB RAM and a blazingly fast 30MHz 286 CPU, if you want to.
There is complete documentation at IBMulator's website. I would recommend reading it thoroughly.