The Olivetti M19 was a personal computer made in 1986 by the Italian company Olivetti. It has an 8088 at 4.77 or 8 MHz and 256–640 KB of RAM.^[1][2] The BIOS is Revision Diagnostics 3.71. In the UK, it was sold by Acorn Computers as the Acorn M19,^[3] with additional software also available via Acorn.^[4] In France, it was available as the Persona 1300,^[5] sold by LogAbax.^[6]

The machine came with three operating systems: MS-DOS 2.11 / 3.1, Concurrent DOS and UCSD p-System.^[1] It was capable of displaying graphics in standard CGA or Plantronics Colorplus mode (320x200 pixel with 16 colors and 640x200 with 4 colors).^[1]

The M19 was sold with two floppy disk drives (360 KB format). A hard drive option was made available later, in the form of a 5 MB (later 10 MB) hard disk in an add-on case (aka "sidecar") attached to the left hand side of the computer by four machine screws.

Paul Maynes, a technician at HBH Computers (one of Olivetti's dealerships in Durban) designed, and SA Signals Manufacturing (also of Durban) produced a bus extension card with a 90-degree bend (purportedly a world-first) that could accommodate a Seagate hard drive controller card. This allowed the second floppy drive to be removed and a 20 MB (later 40 MB) full-height hard drive installed in its place.

In 1987 Olivetti introduced the word processor systems ETV 260 and ETV 500 based on the M19.^{[7][8][9][10]} While the ETV 500 was just a M19 accelerated to 8 MHz and equipped with two 3.5 inch 720 kB floppy drives,^[10] which used optionally an Olivetti ET series typewriter (usually a ET 112 or ET 116) as a serial attached keyboard and daisy wheel printer, the ETV 260 was a fully integrated word processor system with the M19 / ETV 500 accelerated mainboard mounted into a high speed 35 cps daisy wheel typewriter chassis, equipped with two 720 kB floppy drives or a single floppy drives plus an integrated 20 MB SCSI or MFM hard disk.^[8]

Both systems, ETV 260 and ETV, 500 ran MS-DOS 3 and booted directly into Olivetti's own word processor software SWS - Secretary's Work Station,^[11] which could be easy used by people already familiar with Olivetti's ET series typewriters and older CP/M based ETV word processor systems (like the ETV 240, 250 or 350).

• Olivetti M19 with external I/O box attached
• Olivetti M19 rear view
• Inside of the computer, with two 5 1⁄4-inch disk drives
• Mainboard. An AMD P8259A Programmable Interrupt Controller is visible, together with a NEC V20 (µPD70108) main processor (instead of an Intel 8088)

• Olivetti M24
• Olivetti video typewriters
• Plantronics Colorplus