The Omni Convertible could operate up to three processors at a time. That and its unusual but pleasing design make it an interesting collectible.
Omnidata Omni Convertible (1984, desktop)
Original Retail Price: $6,000
Base Configuration: Z80H and TMS9995 CPUs, Omni-DOS, 128K RAM (1MB max), 5.25-inch floppy disk drive, integral monochrome CRT, keyboard/keypad, printer
Important Options: 80186, 80286 or 68000 coprocessor; CP/M Plus, MS-DOS, Xenix, UCSD p-System, or Unix