The DECMATE II shared the same case, power supply unit and RX50 dual floppy drive as the Rainbow 100 and was sold as a desktop or tower stand system. Like DECMATE I and III, it was a member of the PDP-8 family based on the Harris 12-bit 6120, a single chip PDP-8 compatible microprocessor.
The same year, DEC launched the Rainbow 100, a Z80/8088 based system to compete with CP/M and MS-DOS machines, as well as the PDP-11 Professional system.
The DECMATE II was the Decmate series most versatile system. Customer could choose between either one or two dual 5.25" floppy disc drives, or a 5, 10 or 20 MB hard disc, or even 8" floppy drives. Several option boards were also available. Among them, a Z80 card for CP/M compatibility and a graphic board allowing a color monitor to be used.
Digital corporation provided a large range of professional software. However, the Decmate II was mainly used for professionnal word processing, connected to a serial letter quality printer.