The Olivetti M20 is a curious beast of a microcomputer. Originating from Italy (but seeing a release internationally with a slightly altered color scheme), this system was released in March of 1982 for the heart-stopping price of $5,400. Powering this system is a processor rarely seen elsewhere... Zilog, the creator of the 8-bit Z80 microprocessor, had developed their own 16-bit expansion called the Z8000. And this computer used one, clocked at 4MHz.
Base RAM was 128KB, expandable to 512KB. Expanded RAM allowed for the use of color displays instead of a monochrome, greenscale, or amberscale monitor. Though, you couldn’t just connect any old CGA monitor to it, or even use RF and your TV. The Olivetti M20 had its own proprietary video connection, locking you into only being able to use Olivetti’s official monitors. Storage was either a pair of 5.25″ floppy drives, or one 5.25″ floppy drive and a 11.25MB Winchester hard disk drive.
The BIOS is stored on 12KB of ROM, and the stock system boots to a user-unfriendly custom operating system called Professional Computer Operating System, or PCOS. It used a confusing vocabulary of commands, and did not support using the backspace or delete keys! (You have to press CTRL + H to delete a character. What?) File storage was painful and limited, similar to the earliest versions of MS-DOS and CP/M. And there was little to no software available for it, because developers just were not familiar with Zilog’s 16-bit microprocessor, instead focusing their energies on Intel’s microprocessors. Olivetti tried to solve this first by working with Digital Research on a Z8000 port of CP/M, called CP/M-8000. This helped a little, but it came out at a time when IBM was eating everyone’s lunches with their 5150 PC. This is when Olivetti gritted their teeth and... created a 8086 alternate processor card, which turned the computer into a PC-compatible clone that could run MS-DOS. Good save! Too bad the price of the system and the invasive amounts of vendor lock-in made people look elsewhere anyway.
