Pacific Cyber/Metrix

PCM Systems Corporation

File:PCM Systems logo.svg Logo used from 1996 through 2001
Formerly	PCM, Inc. (1975) Pacific Cyber/Metrix (1975–1996)
Company type	Private
Industry	Computers
Founded	1975 (1975)
Defunct	Template:End date and age
Fate	Dissolved
Headquarters	San Ramon, California (1975–1979) Dublin, California (1979–2001)
Key people	Robert Nelson, president
Number of employees	15 (early 2000s)
Website	Template:Web archive

Pacific Cyber/Metrix, Inc. (commonly known as PC/M; initially PCM, Inc., later PCM Systems) was a U.S.-based computer manufacturer founded in 1975 in San Ramon, California.

As a privately held company, PC/M was created by Robert Nelson along with colleagues from Edgerton, Germeshausen, and Grier's San Ramon operations. Nelson held the position of president and principal shareholder. The company specialized in producing microcomputers utilizing the Intersil 6100 microprocessor compatible with the PDP-8 instruction set and also developed CMOS EPROM programmers. PC/M funded its growth solely through revenues generated by its products, avoiding external venture capital. In late 1979, the headquarters were moved to a 6,000-square-foot facility in Dublin, California, where the workforce remained modest—approximately 10 staff in 1979 and around 15 by the early 2000s.

1970s

The company's first offering was the PCM-12, a 12-bit minicomputer built around the Intersil IM6100 CPU designed for compatibility with PDP-8/E software. It supported up to 32K words of 12-bit memory and utilized an 80-line bus accommodating as many as fifteen expansion cards intended primarily for device interfacing and memory augmentation. The PCM-12 featured an integrated bootstrap loader and decrement-address controls on its front panel. Initially marketed as a kit priced between $400 and $600 in early 1976, a fully assembled version was subsequently made available for $1,224. The PCM-12 was recognized as the first mini/microcomputer employing the IM6100 and incorporated an innovative metal card cage backplane.

By mid-1977, PC/M introduced the PCM-12A model which offered improved documentation and cabinetry, added a crystal oscillator enabling variable baud rates, included an absolute loader for tape-based bootstrapping, and incorporated a floppy disk controller that allowed operation under DEC’s OS/8 system. The kit price was adjusted to $679 while assembled units were offered at $989. Expansion cards were broadened to include parallel-serial I/O interfaces as well as high-speed punched card reader-writers compatible with DEC equipment. Additionally, PC/M retrofitted floppy disk support to the original PCM-12 using the dual-floppy controller card 12440 released in late 1977; this controller was sold both as a kit and fully assembled.

Entering early 1978, PC/M provided an array of expansion cards: three types of memory modules including non-volatile CMOS RAM with battery backup; power-fail modules designed to enhance system reliability; upgraded teleprinter interface cards supporting RS-232 and current loop standards; plus digital I/O boards aimed at data acquisition and process control tasks. To foster third-party hardware development, PC/M made available the 12090 prototype board featuring a flexible circuit grid intended for custom expansions.

In February 1978, PC/M expanded into CMOS EPROM programming devices with the Model 66. This programmer targeted Intersil EPROM chips and operated either independently or under computer control for automated programming sequences. It contained an onboard microprocessor managing RAM buffers and provided extensive editing features including fast erase verification accessible via front panel controls. By August of that year, the Model 66 had been upgraded to become the Model 660.

In 1979, PC/M launched Bubbl-Tec, a specialized division focusing on bubble memory technology using Texas Instruments modules—a strategic initiative anticipated to fuel future growth. This development coincided with the company’s relocation from San Ramon to Dublin. Initially dependent on direct sales efforts, Bubbl-Tec soon expanded its reach through distributors across both the United States and Europe alongside internal sales personnel. The division shipped its first bubble memory product in July 1979 followed by additional releases later that year.

1980s

At the beginning of 1980, PC/M introduced the PCM-12 Omega, a larger system resembling mainframe architecture that featured 18 expansion slots alongside a hinged card cage for convenient access. Utilizing the Intersil 6100 processor, it ensured software compatibility with PDP-8/A and similar platforms. The expansion slots were designed to support multiple card dimensions, and the integrated power supply incorporated safeguards such as overvoltage protection and current limiting.

Subsequently, PC/M released the PPS-1201, a single-board computer compatible with Intel’s Multibus backplane. Also powered by the Intersil 6100 processor, it offered up to 4 kilowords of configurable RAM or EPROM memory and came equipped with built-in debugging capabilities, serial RS-232 and 20 mA current loop interfaces, as well as three 12-bit parallel ports. In 1981, the PPS-12 replaced the PPS-1201, adding support for PC/M’s serial–parallel modules and bubble memory devices, improved terminal control software, and compatibility with external development hardware. Designed for field use, it operated on a mere 5 V power supply while consuming only half a watt.

The Bubbl-Tec division of PC/M continued advancing memory card technology through at least 1987, culminating in the PCH-3 Bubbl-Board—an IBM PC-compatible bubble memory expansion card capable of supporting up to 1.5 MB of removable modules. These modules could be utilized with Bubbl-Pacs enclosures or accessed via the Bubbl-Dek external reader, which was designed to fit into standard PC disk drive bays.

In 1988, PC/M broadened its offerings with Hyperflo, a Unix-compatible multiprocessor system priced at $20,300 and built for Motorola’s VMEbus architecture. Each processor board housed four Motorola 68020 CPUs along with two floating-point units. The configuration included resource management boards, memory controllers, and flat memory boards, with optional ROM storage enabling immediate software loading. Hyperflo supported up to eighteen processor boards simultaneously, targeting markets demanding high-performance computing solutions.

1990s – 2001

Throughout the 1990s, Pacific Cyber/Metrix concentrated on VMEbus-based digital signal processors aimed at sectors such as imaging, signal analysis, and scientific instrumentation. Reflecting its shifting product emphasis, the company rebranded as PCM Systems in 1996. By November 2001, PCM Systems officially filed for dissolution with California authorities, signifying the conclusion of its corporate activities.

Further reading

• Simpson, Henry K. (November 1977). "Getting Small: Microcomputers". Digital Design. Benwill Publishing Corporation. 7 (11): 43–65. via the Internet Archive
• Berger, Ivan (1979). Popular Electronics 1979 Electronic Experimenter's Handbook. Ziff-Davis Publishing Company. pp. 93, 102. via the Internet Archive

External links

• Official website (archived April 14, 1997)