DECmate
| Company type | Product line |
|---|---|
| Industry | Computer hardware |
| Predecessor | VT78 |
| Founded | July 1977 |
| Founder | Digital Equipment Corporation |
| Defunct | 1990 |
| Fate | Discontinued |
| Successor | DECmate III, DECmate III+ |
| Products | PDP-8-compatible computers (DECmate series) |
| Owner | Digital Equipment Corporation |
| Parent | Digital Equipment Corporation |
DECmate represented a line of PDP-8-compatible computers manufactured by Digital Equipment Corporation during the late 1970s and early 1980s. These systems utilized either an Intersil 6100 (later replaced by the Harris 6100) or Harris 6120 microprocessor that emulated the 12-bit DEC PDP-8 central processing unit. Tailored primarily for the word processing sector, they ran OS/78 or OS/278—both derivatives of OS/8—and commonly operated the WPS-8 word-processing application. Subsequent versions provided optional Intel 8080 or Z80 processors to support CP/M. The series originated from the VT78, which debuted in July 1977.
VT78
The VT78 was introduced in July 1977, featuring an Intersil 6100 processor clocked at 2.2 MHz and housed within a VT52 enclosure. Its default configuration incorporated an RX02 dual 8-inch floppy disk drive built into the pedestal base.
DECmate
Launched in 1980, this variant employed a VT100 chassis, operated at a 10 MHz clock frequency, and contained 32 Kwords of memory. It was also identified as the VT278.
DECmate II
Released in 1982 as part of DEC’s threefold approach to compete with IBM, alongside the PDP-11-based PRO-350 and Intel 8088-driven Rainbow 100, the DECmate II bore a resemblance to the Rainbow 100 but was powered by the Harris 6120 processor. This model supported two operating environments: the WPS-8 word processing system and COS-310 Commercial Operating System running DIBOL. It featured a monochrome VR201 monitor styled after the (VT220) display, an LK201 keyboard, and two 400 KB single-sided quad-density 5.25-inch RX50 floppy drives. The system included 32 Kwords of RAM dedicated to applications plus another 32 Kwords allocated for device emulation software loaded from floppy disk at startup—commonly termed "slushware."
Expansion possibilities encompassed additional pairs of RX50 drives or RX01/RX02 8-inch floppy drives, along with support for Winchester hard disks. An optional coprocessor board enabled running CP/M, with configurations including a Z80 processor paired with 64 KB RAM or combined Z80 and Intel 8086 boards offering either 256 KB or 512 KB RAM. Manufacturing ceased in 1986, succeeded by the DECmate III introduced in 1984.
DECmate III
The DECmate III arrived in 1984 featuring a more compact case design, color display, an 8 MHz clock speed, two RX50 floppy drives measuring 5.25 inches each, along with 32 KB of user memory and an additional 32 KB for system operations. This model was also known under the name PC238.
DECmate III+
Released in 1985 and discontinued by 1990, the DECmate III+ included a built-in hard disk controller as part of its standard setup but otherwise maintained similarities to the DECmate III. It was alternatively called PC24P.
PDP-8 compatibility
Although designed for word processing tasks, the DECmate lineup encountered compatibility challenges with numerous existing PDP-8 applications due to hardware discrepancies. Differences in I/O interfaces hindered consistent recognition of Control-C for terminating programs, necessitating software patches at both user and system levels. Moreover, slower CPU operation and screen refresh rates compared to earlier PDP-8 models diminished their competitive edge relative to IBM PC platforms.