Floppy Disk Drive, DS/DD, 40 Track, 48 tpi VisiCorp Mouse (Mouse Systems-compatible mice) MS-DOS 2.0 Graphics Adapter compatible with CGA 640x200 monochrome mode Computer monitor capable of displaying CGA 640x200 It will work on newer PCs, but requires a compatible mouse and hard disk partition under 15MB as only the FAT12 file system is supported. In addition, as it revectors some IRQs used by PC/ATs and later, VISIONXT.EXE requires modifications which prevent Graph and other applications from functioning properly. Visi On required Mouse Systems-compatible mice; Microsoft-compatible PC mice, which over time became the standard, were introduced later (in May 1983). Visi On used two mouse drivers. First, loaded in text mode, made mouse registers accessible to the embedded driver, which translated coordinates to cursor position. This internal driver, built-in as a subroutine into VISIONXT.EXE, required Mouse Systems PC-Mouse pointing device. It is not compatible with the Microsoft Mouse standard. Writing Visi On applications required a Unix development environment. Visi On was targeted toward high-end (expensive) PC workstations. Visi On applications were written in a subset of C VisiC, and a third-party could have ported the core software (VisiHost, VisiMachine virtual machine, VISIONXT.EXE in IBM PC DOS version) to Unix, but that never occurred. In 1984, VisiCorp's assets were sold off to Control Data Corporation. Making working copies of the original floppy disks using modern methods is difficult - they are protected using pre-created bad sectors and other methods of floppy disk identification. See also VisiCalc VisiCorp References External links Nathan Lineback's GUI Gallery - VisiCorp Visi On DOS software Operating system APIs Windowing systems