Digital DECmate II
The DECmate II was the follow-on machine to the original DECmate. Both machines
were members of the PDP-8 family based on the Harris 6120 cpu. It had 32k of
RAM and an RX50 dual floppy drive, as well as a monochrome monitor. A common
option was a Z-80 APU board which allowed the machine to run CP/M, though the
Z-80 was also used by the DEC WPS system for various functions. There was also
a color graphics board, and a MFM hard disk subsystem, as well as an XPU board
with an 8086 and either 256k or 512k of RAM, which allowed the DECmate to run
MS-DOS. The disk format used by the XPU board is incompatible with that of
MS-DOS on the Rainbow, and the XPU board also contained a Z-80 coprocessor which
handled the I/O. This made MS-DOS on the XPU board faster than on even 80286
machines. Oddly, DEC tended to tout the machine as a dedicated word processing
system and not as a general purpose computer system.
The DECmate II shared the same case, PSU, and RX50 floppy drive with other
machines, including the Rainbow. Of the 4 DECmate series machines, the
DECmate II is the most expandable and flexible, though there are quite a few
incompatibilities between it and other members of the PDP-8 family from a
software standpoint. The DECmate II was introduced in May 1982 alongside the
Professional 300 series based on the PDP-11, and the Rainbow 100 based on the
Intel 8086 and Zilog Z-80.
Unfortunately, the monochrome monitor for this machine was destroyed during
shipment of it to me, so at the moment I am unable to use the machine at all.
Seeing how it is a DEC-specific piece, and the keyboard plugs into the monitor
vice the CPU, this could be interesting to find. It does have a pair of RX50
floppy drives, the Z-80 APU board, the MFM hard disk option, and the color graphics
option, plus all manuals.
Jeff's Computer Haven Home Page