Powers on without delay.

Rare and highly regarded early portable (“luggable”) computer from Otrona Advanced Systems of Boulder, Colorado. Released in April 1982, the Attaché was widely considered the premium or “Cadillac/BMW” of its class—smaller, sleeker, lighter (~18 lbs), and more refined than contemporaries such as the Osborne 1 or Kaypro.

Only about 5,000–8,000 units were produced before the company ceased operations in 1984, making surviving examples hard to come by.

Key features of this machine:

• Zilog Z80A processor at 4 MHz running CP/M

• Standard 64K RAM

• Dual half-height 5.25-inch floppy drives (360K each typical; higher-density variants also existed)

• Compact built-in 5–5.5-inch monochrome CRT (text 80×24; bit-mapped graphics support)

• Detachable full-travel keyboard that clips over the front for transport

• Two serial ports, external video output, real-time clock, and innovative “Valet” desk accessories in ROM

• Briefcase-sized form factor with carrying handle that doubles as a prop.

This unit shows serial number 4865. Additionally includes floppy Program disks and powder cord.

Other than ensuring it turns on, we have not tested it any further as we simply don’t know how to. We have shared everything we know about this unit here.

Unit can ship nationwide at buyer’s expense.

Clean.