Cromemco was a Mountain View, California microcomputer company known for its high-end Z80-based S-100 bus computers in the early days of the personal computer revolution. The Cromemco Dazzler was the first color graphics card available for personal computers. The company began as a partnership in 1974 between Harry Garland and Roger Melen, two Stanford PhD students. The company was named for their residence at Stanford University (Crothers Memorial, a Stanford dormitory reserved for engineering graduate students). Cromemco was incorporated in 1976. In December 1981 Inc. Magazine named Cromemco in the top ten fastest-growing privately held companies in the U.S.
The collaboration that was to become Cromemco began in 1970 when Harry Garland and Roger Melen, graduate students at Stanford University, began working on a series of articles for Popular Electronics magazine. These articles described construction projects for the electronic hobbyist. Since it was sometimes difficult for the hobbyist to find the needed parts for these projects, Garland and Melen licensed third-party suppliers to provide kits of parts. A kit for one of these projects, an “Op Amp Tester”, was sold by a company called MITS which would later launch a revolutionary microcomputer on the cover of Popular Electronics.
In 1974 Roger Melen was visiting the New York editorial offices of Popular Electronics where he saw a prototype of the MITS Altair microcomputer. Melen was so impressed with this machine that he changed his return flight to California to go through Albuquerque, where he met with Ed Roberts, the president of MITS. At that meeting Roberts encouraged Melen to develop add-on products for the Altair, beginning with the Cyclops digital camera that was slated to appear in the February 1975 issue of Popular Electronics.
On returning to California, Melen and Garland formed a partnership to produce the Cyclops camera and future microcomputer products. They named the company “Cromemco” after the Stanford dorm (Crothers Memorial Hall) where they first began their collaboration.
Melen and Garland began work on the Cyclops Camera interface for the Altair, and this spawned several other projects for their young company. There was no convenient way to store software for the Altair, other than on punched paper tape. To remedy this problem Melen and Garland went to work on designing a programmable read-only memory card they called the “Bytesaver.” The Bytesaver also could support a resident program that allowed the computer to function immediately when it was powered up, without having to first manually load a bootstrap program. The Bytesaver proved to be a very popular peripheral.
There was also no way to see a Cyclops image stored in the Altair. So work began on a graphics interface card which could connect the Altair to a color TV set. This graphics interface, called the Dazzler, was introduced in the February 1976 issue of Popular Electronics.
One use for an Altair Computer with a Dazzler was to play games. But there was no way to interface a game console or joystick to the Altair. So the next project was to design a joystick console and an interface card that supported an 8-bit digital channel and 7 analog channels (called the D+7A). The D+7A could do much more than just interface a joystick, however, and it was this card that first allowed microcomputers to be connected to the world of data acquisition and industrial computing.
Cromemco called themselves “Specialists in Computer Peripherals” and had a reputation for innovative designs and quality construction. They were, however, just a few steps away from offering their own computer system.
From boards to systems
The first computer released by Cromemco was the Z-1 in August 1976. The Z-1 came with 8K of static RAM and used the same chassis as the IMSAI 8080 but featured the Z80 microprocessor rather than the IMSAI computer's Intel 8080 chip. The Z-1 was succeeded by the Z-2 in June 1977, which featured 64K of RAM and the ability to run Cromemco DOS (CDOS), a CP/M-like operating system. The Z-2 also added a parallel interface in addition to an RS-232C serial port and no longer included the large panel of switches that had been part of the Z-1 model.
Cromemco re-packaged their systems to produce the System One, followed by the larger System Two and System Three. The System Three, announced in 1978 was capable of running both FORTRAN IV and Z80 BASIC programming languages. The System Three was designed for multiuser professional use and included an optional hard disk, CRT terminal, printer and the main computer unit. In 1979, Cromemco released CROMIX, the first Unix-like operating system for microcomputers. CROMIX initially ran on the System Three and would later run on Cromemco systems using the Motorola 68K family of microprocessors.
|System||Year Introduced||S-100 slots||Internal Floppy Disk||Internal Hard Disk|
|System One CS-1||1981||8||2 x 5-inch||n/a|
|System One CS-1H||1981||8||1 x 5-inch||5 megabytes|
|System Two Z-2D||1978||21||2 x 5-inch||n/a|
|System Two Z-2H||1980||12||2 x 5-inch||11 megabytes|
|System Three||1978||21||4 x 8-inch||n/a|
In 1982, Cromemco introduced their 100-series of Unix machines, based on the Motorola 68000 family instead of the Zilog Z80. The original CS100 was packaged in a relatively small case, while the CS200 was based on the larger Z-2 family case using MC68010, and the 400 was in a PC-style tower case with either the 68010 or 68020. Cromemco also introduced the C-10 personal computer in 1982, a Z-80 floppy disk based system for the low end of the market.
At its peak in 1983, Cromemco employed over 500 people and had annual revenues of US$55 million. The company was wholly owned by Garland and Melen until it was sold to Dynatech in 1987 as a supplier to their ColorGraphics Weather Systems subsidiary. The European division of Cromemco reorganized as Cromemco AG and is still in business.
Cromemco was known for its engineering excellence and design creativity. “If they hired you into their R&D Department, they gave you an office and a computer and asked you what you wanted to do” recalls Roger Sippl, an early Cromemco employee. Cromemco’s engineering firsts for microcomputer systems include the first digital camera (the Cyclops Camera), the first color graphics (the Cromemco Dazzler), the first programmable storage (the Bytesaver), and the first Unix-like operating system (Cromix).
Cromemco drew on engineering talent from Stanford University, the Homebrew Computer Club, and even its own distributors. Joe McCrate, Curt Terwilliger, Tom McCalmont, Jerry May, and Marvin Kausch had all been students of the company founders at Stanford University.   Ed Hall and Li-Chen Wang came to Cromemco through the Homebrew Computer Club. Nik Ivancic, Boris Krtolica, and Egon Zakrajšek joined from Cromemco’s distributor in Yugoslavia where they had developed structural engineering software for Cromemco systems.
Several Cromemco engineers went on to found other Silicon Valley companies. Roger Sippl, Laura King, and Roy Harrington formed Informix Corporation. Tom McCalmont founded REgrid Power Inc. and later McCalmont Engineering. Jeff Johnson went on to found UI Wizards, Inc. and publish best-selling books on software user-interface design.
In 1981 a study was commissioned by the United States Air Force Systems Command to select a microcomputer for the Theater Air Control System (TACS). From a field of 149 microcomputers the Final Technical Report concluded that “the equipment offered by Cromemco is the most responsive to the general selection criteria.” In the years following this study the United States Air Force became a major customer for Cromemco computers. 
Cromemco developed a special version of the CS-200 computer (called the CS-250) to meet the requirements of the Air Force's Mission Support System (MSS). The CS-250 had a removable hard disk based on patented Cromemco technology The United States Air Force deployed 600 Cromemco Systems from 1985 to 1996 as Mission Support Systems for the F-15, F-16, and F-111 aircraft. These systems received their first war time use in Operation Desert Storm in 1991.
Cromemco systems were also widely used in commercial applications, including at the Chicago Mercantile Exchange (CME) where a bank of 60 Cromemco Z-2 systems were used to process trades. Each Z-2 system was populated with Cromemco Octart interface cards, with each card supporting 8 terminals on the trading floor. For ten years, from 1982 to 1992, all trades at the CME were processed by these systems. In 1992 the Cromemco systems were replaced by IBM PS/2 computers.
Cromemco systems were also broadly adopted by U.S. television stations for generating weather and art graphics, using software developed by ColorGraphics Weather Systems. By 1986 more than 80 percent of the major-market television stations in the U.S. used Cromemco systems to produce news and weather graphics. 
- Cromemco Bytesaver EPROM programmer/memory card
- Cromemco CYCLOPS digital camera
- Cromemco Dazzler video card
- Cromemco 4FDC 4 channel floppy controller card
- Cromemco 16FDC 4/16 channel floppy controller card
- Cromemco 64FDC 4/16 channel floppy controller card
- Cromemco IOP input / output processor
- Cromemco PRI parallel interface card
- Cromemco CSP c-bus interface card
- Cromemco TDS tape interface card
- Cromemco TUART 2 channel serial interface card
- Cromemco QUADART 4 channel serial interface card
- Cromemco OCTART 8 channel serial interface card
- Cromemco Z-2
- Dataindustrier AB
- Homebrew Computer Club
- S-100 bus
- Ketchum, Jr., Bradford W. (December, 1981). "The INC. Private 100". Inc. 3(12): 35–44.
- "The Cromemco Story". I/O News 1 (1): 6–11. September/October 1980. ISSN 0274-9998.
- Garland, Harry; Melen, Roger (1971). "Build the Fil-oscillator". Popular Electronics 34 (5): 58–62.
- Garland, Harry; Melen, Roger (1971). "Add Triggered Sweep to your Scope". Popular Electronics 35 (1): 65–66.
- Garland, Harry; Melen, Roger (1971). "Build the Muscle Whistler". Popular Electronics 35 (5): 60–62.
- Garland, Harry; Melen, Roger (1973). "Build a Low-Cost Op Amp Tester". Popular Electronics Including Electronics World 4 (6): 34–35.
- Solomon, Les. "Solomon's Memory". atariarchives.org. Retrieved 2012-02-10.
- Freiberger, Paul; Swaine, Michael (2000). Fire in the Valley: The Making of the Personal Computer (Second ed.). McGraw-Hill. p. 48.
- Walker, Terry; Garland, Harry; Melen, Roger (1975). "Build Cyclops". Popular Electronics 7 (2): 27–31.
- Levy, Steven (1984). Hackers: Heroes of the Computer Revolution. Garden City, NY: Anchor Press/Doubleday. p. 202. ISBN 0-385-19195-2.
- Veit, Stan (1993). "Cromemco: Innovation and Reliability". Stan Veit's History of the Personal Computer. Asheville, North Carolina: WorldComm. pp. 104–105. ISBN 1-56664-023-7. "The Bytesaver proved to be a very popular peripheral for the Altair and IMSAI computers."
- Walker, Terry; Melen, Roger; Garland, Harry; Hall, Ed (1975). "Build the TV Dazzler". Popular Electronics 9 (2): 31–40.
- Veit, Stan (1993). "Cromemco: Innovation and Reliability". Stan Veit's History of the Personal Computer. Asheville, North Carolina: WorldComm. p. 107. ISBN 1-56664-023-7. "The D+7A analog Interface board was one of the most important peripherals that Cromemco ever made, because it provided a gateway into the word of scientific and industrial computing."
- Veit, Stan (1993). "Cromemco: Innovation and Reliability". Stan Veit's History of the Personal Computer. Asheville, North Carolina: WorldComm. p. 106. ISBN 1-56664-023-7. "Their product were noted for both innovative design and quality construction."
- History of Cromemco, from Robert Kuhmann, January 2008
- Cromemco Z-1, Old-Computers.com
- Cromemco Z-2
- Cromemco System I/II/III, from OLD-COMPUTERS.COM ONLINE MUSEUM "CDOS is a CP/M like operating system."
- System Three advertisement
- Cromemco System I / II / III, Old-Computers.com
- Cromemco & UNIX V, advertisement in Spanish
- Cromemco C-10, see advertisement
- "Oral History of Roger Sippl". Computer History Museum. Retrieved 2013-05-2.
- McCrate, Joe (July/August 1981). "Major New Enhancements to CROMIX". I/O News 1 (6): 9–12. ISSN 0274-9998.
- Terwilliger, Curt (November/December1980). "A New Approach to System Design: The C-Bus, IOP, and QUADART". I/O News 1 (2): 1,22–25. ISSN 0274-9998.
- Ritch, Emma (July 25, 2008). "REgrid's McCalmont comes full circle as solar stalwart". Silicon Valley/San Jose Business Journal (Business Journal Publications, Inc.) 26 (12): 16–17. ""He was one of several students plucked out of a class taught by professor Harry Garland to join startup microcomputer company Cromemco"
- Segaller, Stephen (1998). Nerds 2.0.1:A Brief History of the Internet. p. 143.
- Nardini, Dubravko; Nikolaj Ivancic, Miljenko Srikoc (January/February 1981). "STRESS:A Program for Linear Static Analysis of Engineering Structures". I/O News 1 (3): 1,14–17. ISSN 0274-9998.
- "UI Wizards, Inc.". Retrieved 2013-05-2.
- Bunker-Ramo Corp. "Microprocessor Front-End Terminal Study". RA-TR-81-149 Final Technical Report, June 1981, page 76. Retrieved 3/31/2013.
- "Cromemco to supply Micros to Air Force". InfoWorld: 11. June 28, 1982.
- Creagan, Danny J. (1983). Computer Assisted Instruction in Basic. Air Force Institute of Technology. "The Air Force recently approved the purchase of 1500 Cromemco microcomputers."
- "U.S. Patent #4,870,605". USPTO.
- Kuhman, Robert. "The Cro's Nest RCP/M-RBBS". www.kuhmann.com. Retrieved 2012-02-10.
- Aviation Week & Space Technology 126 (22): 105. June 1, 1987.
- Gillott, Mark A. (1998). Breaking the Mission Planning Bottleneck: A New Paradigm. pp. 5–6.
- Breeding, Gary (January/February 1984). "Cromemco Systems Network Transactions at Chaotic Exchange". I/O News 3 (6): 20. ISSN 0274-9998.
- "CME Taps Datacode To Distribute Quotation Data To Floor Traders". WatersTechnology. January 27, 1992. Retrieved 3/3/2013.
- UNIX Review (Review Publications Company) 4. 1986. "Cromemco, Inc., whose hardware is used to produce news and weather graphics for more than 80 percent of the major-market television stations in the US, and ColorGraphics Systems, Inc. have reached a joint marketing agreement..."
|Wikimedia Commons has media related to: Cromemco|
- Stanford University: "Cromemco History" page. The beginnings...
- Marcus Bennett: "Cromemco Treasure Trove". Downloadable Cromemco S-100 Photos, Manuals, & Cromemco CDOS and Cromix software.
- Cromemco Z-1 brochure (circa 1976).
- "Cromemco Z-2D" (circa 1977) Zilog Z80, S-100 computer.
- "Cromemco System One" Motorola 68000, picture & specs (circa 1982).
- Another view of the "Cromemco System One".
- The compact "Cromemco System Zero" 6-slot S-100 computer.
- "Cromemco C-10SP" review from Creative Computing magazine, January 1984.
- "Cromemco C-10" personal computer photograph, specs, & advertisement (circa 1982).
- "Cromemco CS-100 & CS-300" computers (circa 1984–1985).
- "Cromemco CS-250" (circa 1990), Motorola MC68020, S-100 computer.
- "Cromemco CS-250" (circa 1990) Maxtor 190MB ST506 MFM hard-drive.
- "Comprehensive Cromemco Part Number Xref" S-100 Systems, Boards, Peripherals, & Manuals (Hardware & Software).
- Digibarn Cromemco Systems
- Dave's Old Computers, pictures, disk images and manuals.
- Early Hard Drive Ads
- X:\static\S100\cromemco, software and various documents
- The only CPU card to give you 4MHz speed
- CROMIX Cromemco's outstanding UNIX like operating system