The range was a development of the VT78 which was introduced in 1978.
Introduced in 1978, this machine was built into a VT52 case and had an Intersil 6100 CPU running at 2.2 MHz. The standard configuration included an RX02 dual 8-inch floppy disk unit which was held by the pedestal the computer rested on.
Introduced in 1980, this machine was built into a VT100 case. It had a 10 MHz clock, 32 KWords of memory. It was also known as the VT278.
As part of a three-pronged strategy against IBM, the company released this model at the same time as the PDP-11-based PRO-380 and the Intel 8088-based Rainbow 100. Like these other machines, it had a monochrome VR201 (VT220-style) monitor, an LK201 keyboard and dual 400K single-sided quad-density 5.25 inch RX50 floppy disk drives. It had 32 Kwords of RAM for use by programs, and a further 32 Kwords containing code which was used for device emulation. Code running in this second bank was nicknamed slushware, in contrast to firmware since it was loaded from floppy disk as the machine booted. It was also known as the PC278.
It could be expanded, either by adding another pair of 5.25 inch floppy disk drives, and it could also support either an additional pair of RX01 or RX02 8 inch floppy disk drives or a winchester disk.
It could also have a coprocessor board added, to allow it to run CP/M. There was a choice of three coprocessor boards, one with a Z80 and 64 KB RAM, and a choice of two boards with both a Z80 and an Intel 8086, the difference being that they had either 256 KB or 512 KB RAM.
Manufacture ceased in 1986. It was superseded by the DECmate III, introduced in 1984
This was introduced in 1985 and withdrawn in 1990. It included a hard disk controller as part of the basic configuration. Otherwise, it was very similar to the DECmate III. It was also known as the PC24P.
The DECmates were acceptable for word-processing, but due to various hardware quirks, were somewhat incompatible with many existing PDP-8 programs. The I/O interfaces worked slightly differently, which meant that most existing user and system programs could not detect Control-C and exit reliably. Every program, both user and system, had to be patched to fix this anomaly. Additionally, the CPU and screen update speeds were noticeably slower than the older PDP-8 systems.