The Victor 9000 (also called Sirius in Europe) is an Intel 8088 based computer which predated the original IBM-PC. It used 5 1/2 inch floppies with a capacity of 1.2 MB (this was possible through variable rotation speed of the drive). It was possible to boot either MSDOS or CPM-86. It also had high resolution graphics (implemented by loadable modules). Among other things, it was famous for the high quality keyboard. It was not BIOS compatible with the IBM-PC, therefore it vanished from the market when the IBM-PC arrived, despite being technically superior. It had 4 slots for expansion modules and there was a module which made it IBM-compatible. Among users, this module was called PC-downgrade. Donated by Prof. Erich Neuwirth of the University of Vienna.
This very machine here was used to implement HOMEX and expert system for homeopathic medicine (implemented in Turbo Pascal, fitting into 64 KB). Since MSDOS did not support fast screen writing and mouse control at that time, drivers for screen and mouse had to be written in assembler. The machine's BIOS was documented well enough to make it possible to write such drivers with the assembler support of Turbo Pascal. Exhibit on YouTube: http://www.youtube.com/watch?v=Lzj_i89R7M0