--- title: IMSAI 8080 categories: - Computers types: - Home Computer origins: - U.S.A. years: - '1976' cpus: - Intel 8080A params: name: '8080' image: /media/museum/photos/imsai_8080_1.jpg company: /companies/imsai company_name: IMSAI specs: - label: NAME value: '8080' - label: MANUFACTURER value: IMSAI - label: TYPE value: Home Computer - label: ORIGIN value: U.S.A. - label: YEAR value: Start of 1976 - label: BUILT IN LANGUAGE value: None - label: KEYBOARD value: None, front panel switches are used to program the system - label: CPU value: Intel 8080A (rarely 8080) - label: SPEED value: 2 MHz (each instruction takes 4 clock cycles) - label: RAM value: 256 bytes - label: ROM value: Unknown - label: TEXT MODES value: Depending on the video terminal used (optional 64 x 12 card) - label: GRAPHIC MODES value: None - label: COLORS value: None - label: SOUND value: No speaker in the case - label: SIZE / WEIGHT value: Unknown - label: I/O PORTS value: I/O port - label: BUILT IN MEDIA value: None - label: OS value: Unknown - label: POWER SUPPLY value: Buit-in power supply unit - label: PERIPHERALS value: S-100 cards - label: PRICE value: $439 kit, $621 assembled (1976) - $599 kit, $931 assembled (1977) tabs: - photos - adverts - hardware - emulators - links forum_thread: 388 photos: - title: IMSAI 8080 subtitle: '' text: '' image: /media/museum/photos/imsai_8080_front_2.jpg - title: FRONT PANEL subtitle: '' text: '' image: /media/museum/photos/imsai_8080_front_3.jpg - title: BACK subtitle: '' text: '' image: /media/museum/photos/imsai_8080_back.jpg - title: COMPLETE SYSTEM subtitle: '' text: |- Complete system including:\ \- A dual 8" F.D.D unit from Digital Systems\ \- A serial video terminal. IMSAI 8080 could use the **Tarbell** Floppy Disk Interface to connect up to 4 F.D Drives (243 KB each - 250 Kb / second).\ Controller chip was a Western Digital 1771.\ Operating system vas a modified CP/M image: /media/museum/photos/imsai_8080_system_1.jpg - title: IMSAI8080 WITH FLOPPY DISK DRIVE subtitle: '' text: picture courtesy of Yellowchoo Ebay seller image: /media/museum/photos/imsai8080_withdiskdrive.jpg - title: INSIDE 8080 subtitle: '' text: |- Inside this 8080 case, one finds: **(1)** A processor card\ **(2)** Four memory cards\ **(3)** Three Input/Output and peripherals cards\ **(4)** Power supply transformer and condensers image: /media/museum/photos/imsai_8080_inside_1.jpg - title: POWER SUPPLY subtitle: '' text: '' image: /media/museum/photos/imsai_8080_powersup_1.jpg - title: MANUAL subtitle: '' text: '' image: /media/museum/photos/imsai_8080_manual_1.jpg - title: THE TARBELL CASSETTE INTERFACE subtitle: '' text: This interface can be used with IMSAI or ALTAIR. It transfers from 187 to 540 bytes / second. image: /media/museum/photos/tarbell_k7.jpg - title: THE IMSAI 750 subtitle: '' text: I don't know exactly what is this computer. Surely the successor of the IMSAI 8080. image: /media/museum/photos/imsai4.jpg adverts: - title: 1977 ADVERT subtitle: '' text: |- The advert said : Waiting for you, all the incredible performance and power of the IMSAI 8080. And at a price you would normally pay for a home music system : $699 in kit, $931 assembled... **WORLS OF USES :** The IMSAI 8080 is a superbly engineered, putting litterally hundreds of applications and uses at your fingertype... **GROWS WITH YOU :** The IMSAI 8080 is designed for many years of pleasure. With its open-chassis engineering, you can expand your system by adding peripherals and interfaces. The 22 slots and 28 amperes power supply mean that you can plug-in todays's plus tomorrow's modules. Right now, you can add a module for displaying color graphics and characters on TV, a ready-to-use keyboard, a cassette tape recorder, small and large printers... **EASY TO PROGRAM :** With our BASIC language, you can operate the IMSAI 8080 quickly and easily. Thechnically knowledgeable ? Use our assembly language to develop sophisticated and unique software. image: /media/museum/pubs/imsai_8080_pub_1.jpg - title: BYTE SHOPPER subtitle: '' text: Spring 1978 issue of Byte shopper guide image: /media/museum/pubs/imsai_8080_byteshopper_s1.jpg - title: POWER... IS EXPENSIVE! subtitle: '' text: |- The Megabyte Micro was a special version of the Imsai made with 16 x 64 KB RAM boards (Imsai just introduced this card) and a control board called Intelligent Memory Manager. A mapping configurator allowed each user to use its own protected RAM area. Prices : 64 KB RAM board Kit: **$2599**, assembled: **$3899**\ Intelligent Memory Manager board: **$299**, assembled: **$399** To note: in 1977, 1 MB RAM costed... $62384! image: /media/museum/pubs/imsai_8080_pub_2.jpg - title: NOT REALLY AN IMSAI! subtitle: '' text: |- In october 1979, the IMSAI company went bankrupt. The IMSAI brand name and the spare parts stock were sold to the **Fischer-Freitas** Company. This 1982 advert shows a Z80 CP/M based computer Fisher-Freitas tried to sell with the IMSAI name, without success. Fisher-Freitas is still selling original parts for the 8080 model! and continue maintaining a nice 8080 history web site (see the Web links section). image: /media/museum/pubs/imsai_8080_pub_3.jpg - title: ADVERT FROM NEW ZEALAND subtitle: '' text: |- In November 1976, the assembled basic version cost A$931, the unassembled version cost A$599. Thanks to **Murray Moffatt** from New Zealand image: /media/museum/pubs/imsai_8080_pub_s4.jpg hardware: - title: F.D. SYSTEM subtitle: '' text: |- Advert (March 1977) said: The North Star Micro-Disk System uses the Shugart minifloppy disc drive. The controller is an S-100 compatible PC board with on-board PROM for bootstrap load. It can control up to three drives. With the PROM bootstrap, we provide our powerful extended Basic (10 Kb) with sequential and random disk file accessing.\ Each 5'' diskette has 90k data byte capacity. Basic loads in less than 2 seconds. Micro-Disk system (kit) **$699**\ Micro-Disk system (Assembled) **$799**\ Additional drive **$425**\ Diskette **$4.5** image: /media/museum/hardware/altair_8800_fd_1.jpg - title: ADVERT DATED SEPTEMBER 1976 subtitle: '' text: |- \- PROM board\ \- TV Dazzler video card\ \- Analog I/O board\ \- Cyclop optical digitalizer image: null - title: US ADVERT (1977) subtitle: '' text: You could use these joysticks with the Altair or any S100 bus system. They connect to the Cromenco D+7/A I/O board and were meant to play the games available for the Cromenco TV Dazzler, the first video card for personal computer. image: /media/museum/hardware/cromenco-joysticks_pub_1-1977.jpg - title: ADVERT (NOVEMBER 1976) subtitle: '' text: '' image: null emulators: - title: Altair and IMSAI Emulators url: http://www.threedee.com/jcm/emu8080/index.html platform: Windows text: Altair 8800b and the IMSAI 8080 emulators for Windows - title: Altair32 Emulator Project url: http://highgate.comm.sfu.ca/~rcini/classiccmp/Altair32.htm platform: Windows text: Windows emulator based on the original emulator of Claus Giloi links: - title: IMSAI.NET url: http://www.imsai.net/ text: Where you can buy a 20 Mhz. Z80 version of the 8080! - title: oldcomputers.net url: http://oldcomputers.net/imsai8080.html text: Nice page with beautiful pictures - title: When PCs where Micros url: http://rwebs.net/micros/Imsai/Default.htm text: Nice original IMSAI brochure put on the web - title: www.obsoletecomputermuseum.org url: http://www.obsoletecomputermuseum.org/imsai/ text: nice detailed IMSAI page related: - /museum/mits-altair-8800 oc_id: 389 source: url: https://web.archive.org/web/20230328234541/http://www.old-computers.com/museum/computer.asp?c=389 date: '2023-03-28' --- After seeing the instant success of the MITS [ALTAIR 8800](/museum/mits-altair-8800/) computer, the first "home computer" ever made, others soon tried their luck in this new business space. One of the first to do so was Bill Millard who founded IMS Associates. The computer they designed, the IMSAI 8080, was very similar to the Altair 8800 and was designed to run the same software. However, it was a much better design, with a higher specification power supply, an anodized aluminum chassis, 22 slots on the S-100 bus, and a great front panel design. The IMSAI 8080 aimed to take advantage of the Altair's popularity, the inability of MITS to meet a growing demand for the product, and the need to improve on some of the internal components. Like the Altair, the IMSAI came either in kit form, or preassembled at the factory. At the production starting, the IMSAI was shipped deliberately missing many parts in the kit version, because the company hadn't received them yet. But since IMSAI promised delivery by a certain date, they shipped them anyway! Like the Altair system, there were no keyboard but a front panel and switches used to program the system. The LED's blinked, depending of the values found on the address and data buses. One could manually stop the CPU, single step the CPU, and read and write to memory locations. In the end, the IMSAI outlasted the Altair by several years. Owners were delighted to see it featured in the 1984 movie "War Games", with Matthew Broderick and Ally Sheedy. Through the years, it has remained a much-beloved design amongst vintage computer collectors, and newly-manufactured parts and documentation are still available! (see Web links)