IMSAI 8080 computer at the Computer History Museum

The IMSAI 8080 is an early

microcomputer A microcomputer is a small, relatively inexpensive computer having a central processing unit (CPU) made out of a microprocessor. The computer also includes memory and input/output (I/O) circuitry together mounted on a printed circuit board (P ...

released in late 1975, based on the

Intel 8080 The Intel 8080 is Intel's second 8-bit computing, 8-bit microprocessor. Introduced in April 1974, the 8080 was an enhanced successor to the earlier Intel 8008 microprocessor, although without binary compatibility.'' Electronic News'' was a week ...

(and later

8085 The Intel 8085 ("''eighty-eighty-five''") is an 8-bit microprocessor produced by Intel and introduced in March 1976. It is software-binary compatible with the more-famous Intel 8080. It is the last 8-bit microprocessor developed by Intel. The ...

) and

S-100 bus The S-100 bus or Altair bus, later standardized as IEEE 696-1983 ''(inactive-withdrawn)'', is an early computer bus designed in 1974 as a part of the Altair 8800. The bus was the first industry standard expansion bus for the microcomputer in ...

. It is a clone of its main competitor, the earlier MITS Altair 8800. The IMSAI is largely regarded as the first "clone" microcomputer. The IMSAI machine runs a highly modified version of the

CP/M operating system CP/M, originally standing for Control Program/Monitor and later Control Program for Microcomputers, is a mass-market operating system created in 1974 for Intel 8080/ 85-based microcomputers by Gary Kildall of Digital Research, Inc. CP/M is ...

called

IMDOS IMDOS was a modified version of the CP/M operating system for Intel 8080 processors, used by IMS Associates, Inc. (IMS) for their IMSAI 8080 personal computer. Since Micro Instrumentation and Telemetry Systems, MITS would not license their operatin ...

. It was developed, manufactured and sold by

IMS Associates, Inc. IMS Associates, Inc., or IMSAI, was a microcomputer company, responsible for one of the earliest successes in personal computer, personal computing, the IMSAI 8080. The company was founded in 1973 by William Millard (businessman), William Millard ...

(later renamed to IMSAI Manufacturing Corp). In total, between 17,000 and 20,000 units were produced from 1975 to 1978.

History

In May 1972, William Millard started a business called IMS Associates (IMS) in the areas of computer consulting and engineering, using his home as an office. By 1973, Millard incorporated the business and soon found funding for it, receiving several contracts, all for software. IMS stood for "Information Management Services". In 1974, IMS was contacted by a client which wanted a "

workstation A workstation is a special computer designed for technical or computational science, scientific applications. Intended primarily to be used by a single user, they are commonly connected to a local area network and run multi-user operating syste ...

system" that could complete jobs for any

General Motors General Motors Company (GM) is an American Multinational corporation, multinational Automotive industry, automotive manufacturing company headquartered in Detroit, Michigan, United States. The company is most known for owning and manufacturing f ...

car dealership. IMS planned a system including a

terminal Terminal may refer to: Computing Hardware * Computer terminal, a set of primary input and output devices for a computer * Terminal (electronics), a device for joining electrical circuits together ** Battery terminal, electrical contact used to ...

, small computer,

printer Printer may refer to: Technology * Printer (publishing), a person * Printer (computing), a hardware device * Optical printer for motion picture films People * Nariman Printer (fl. c. 1940), Indian journalist and activist * James Printer (1640 ...

, and special software. Five of these workstations were to have common access to a

hard disk drive A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating hard disk drive platter, pla ...

, which would be controlled by a small computer. Eventually product development was stopped. Millard and his chief engineer Joe Killian turned to the

microprocessor A microprocessor is a computer processor (computing), processor for which the data processing logic and control is included on a single integrated circuit (IC), or a small number of ICs. The microprocessor contains the arithmetic, logic, a ...

. Intel had announced the 8080 chip, and compared to the 4004 to which IMS Associates had been first introduced, it looked like a "real computer". Full-scale development of the IMSAI 8080 was put into action using the existing Altair 8800's

, and by October 1975 an ad was placed in ''

Popular Electronics ''Popular Electronics'' was an American magazine published by John August Media, LLC, and hosted at TechnicaCuriosa.com. The magazine was started by Ziff-Davis Publishing Company in October 1954 for electronics hobbyists and experimenters. It so ...

'', receiving positive reactions. Advertisement: IMSAI 8080 computer with 1K of RAM. $439 kit, $621 assembled. IMS shipped the first IMSAI 8080 kits on 16 December 1975, before turning to fully assembled units. "Later that day, December 16

975 Year 975 ( CMLXXV) was a common year starting on Friday of the Julian calendar. Events By place Byzantine Empire * Arab–Byzantine War: Emperor John I raids Mesopotamia and invades Syria, using the Byzantine base at Antioch to pres ...

United Parcel Service picked up the first shipment of 50 IMS computer kits for delivery to customers." In 1976, IMS was renamed to IMSAI Manufacturing Corporation because by then, they were a manufacturing company, not a consulting firm. In 1977, IMSAI marketing director Seymour I. Rubinstein paid

Gary Kildall Gary Arlen Kildall (; May 19, 1942 – July 11, 1994) was an American computer scientist and microcomputer entrepreneur. During the 1970s, Kildall created the CP/M operating system among other operating systems and programming tools, and s ...

$25,000 for the right to run

CP/M CP/M, originally standing for Control Program/Monitor and later Control Program for Microcomputers, is a mass-market operating system created in 1974 for Intel 8080/Intel 8085, 85-based microcomputers by Gary Kildall of Digital Research, Dig ...

version 1.3, which eventually evolved into an operating system called

, on IMSAI 8080 computers. Other manufacturers followed and CP/M eventually became the ''de facto'' standard 8-bit operating system. By October 1979, the IMSAI corporation was

bankrupt Bankruptcy is a legal process through which people or other entities who cannot repay debts to creditors may seek relief from some or all of their debts. In most jurisdictions, bankruptcy is imposed by a court order, often initiated by the de ...

. The VDP (all-in-one) computer had sold poorly and was not competitive with the Radio Shack

TRS-80 The TRS-80 Micro Computer System (TRS-80, later renamed the Model I to distinguish it from successors) is a desktop microcomputer developed by American company Tandy Corporation and sold through their Radio Shack stores. Launched in 1977, it is ...

Commodore PET The Commodore PET is a line of personal computers produced starting in 1977 by Commodore International. A single all-in-one case combines a MOS Technology 6502 microprocessor, Commodore BASIC in read-only memory, keyboard, monochrome monitor ...

, and

Apple II Apple II ("apple Roman numerals, two", stylized as Apple ][) is a series of microcomputers manufactured by Apple Computer, Inc. from 1977 to 1993. The Apple II (original), original Apple II model, which gave the series its name, was designed ...

computers. The 'IMSAI' trademark was acquired by Thomas Fischer (IMSAI), Thomas "Todd" Fischer and Nancy Freitas (former early employees of IMS Associates), who continued manufacturing the computers under the IMSAI name as a division of Fischer-Freitas Co. Support for early IMSAI systems continues. The first registration of the trademark IMSAI was on 17 January 1980. The right to the word mark IMSAI expired on 6 April 2004 because Thomas Fischer did not correctly submit the required documents for renewal. IMSAI8080 TV11

IMSAI 8080 replicas have entered the market, due in part to the legality of copying hardware designs encouraging amateur technophiles to make backwards compatible machines, with the retro aesthetics. The color scheme matches the original IMS 1973 "Hypercube" project, but some peripherals such as the floppy are simulated and instead use Wi-fi.

VDP series

In mid-1977, IMSAI released the VDP-series, based on the Intel 8085. According to the product description of January 1978, many different models were released, with 32K or 64K memory and a 9" (VDP4x-range) or 12" (VDP8x-range) video display. For example, the VDP-40 had two 5-1/4" disk drives, a 9" 40-character-wide display and a 2K

ROM Rom, or ROM may refer to: Biomechanics and medicine * Risk of mortality, a medical classification to estimate the likelihood of death for a patient * Rupture of membranes, a term used during pregnancy to describe a rupture of the amniotic sac * ...

monitor all in one cabinet. The built-in keyboard had a 8035 microprocessor and a serial interface to the main board. The VIO-C video board had 2K firmware ROM, 2K character generator read-only memory (ROM) with 256 characters and 2K of refresh memory. The VDP80/1050 was listed in January 1978 for and the VDP-40/64 for .

History

VDP series

Further reading

References

External links