website/content/museum/imsai-8080.md

title, categories, types, origins, years, cpus, params

title	categories	types	origins	years	cpus	params
IMSAI 8080	Computers	Home Computer	U.S.A.	1976	Intel 8080A	name image company company_name specs tabs photos adverts hardware emulators links comments related oc_id source 8080 /media/museum/photos/imsai_8080_1.jpg /companies/imsai IMSAI label value NAME 8080 label value MANUFACTURER IMSAI label value TYPE Home Computer label value ORIGIN U.S.A. label value YEAR Start of 1976 label value BUILT IN LANGUAGE None label value KEYBOARD None, front panel switches are used to program the system label value CPU Intel 8080A (rarely 8080) label value SPEED 2 MHz (each instruction takes 4 clock cycles) label value RAM 256 bytes label value ROM Unknown label value TEXT MODES Depending on the video terminal used (optional 64 x 12 card) label value GRAPHIC MODES None label value COLORS None label value SOUND No speaker in the case label value SIZE / WEIGHT Unknown label value I/O PORTS I/O port label value BUILT IN MEDIA None label value OS Unknown label value POWER SUPPLY Buit-in power supply unit label value PERIPHERALS S-100 cards label value PRICE $439 kit, $621 assembled (1976) - $599 kit, $931 assembled (1977) photos adverts hardware emulators links title subtitle text image IMSAI 8080 /media/museum/photos/imsai_8080_front_2.jpg title subtitle text image FRONT PANEL /media/museum/photos/imsai_8080_front_3.jpg title subtitle text image BACK /media/museum/photos/imsai_8080_back.jpg title subtitle text image COMPLETE SYSTEM 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 /media/museum/photos/imsai_8080_system_1.jpg title subtitle text image IMSAI8080 WITH FLOPPY DISK DRIVE picture courtesy of Yellowchoo Ebay seller /media/museum/photos/imsai8080_withdiskdrive.jpg title subtitle text image INSIDE 8080 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 /media/museum/photos/imsai_8080_inside_1.jpg title subtitle text image POWER SUPPLY /media/museum/photos/imsai_8080_powersup_1.jpg title subtitle text image MANUAL /media/museum/photos/imsai_8080_manual_1.jpg title subtitle text image THE TARBELL CASSETTE INTERFACE This interface can be used with IMSAI or ALTAIR. It transfers from 187 to 540 bytes / second. /media/museum/photos/tarbell_k7.jpg title subtitle text image THE IMSAI 750 I don't know exactly what is this computer. Surely the successor of the IMSAI 8080. /media/museum/photos/imsai4.jpg title subtitle text image 1977 ADVERT 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. /media/museum/pubs/imsai_8080_pub_1.jpg title subtitle text image BYTE SHOPPER Spring 1978 issue of Byte shopper guide /media/museum/pubs/imsai_8080_byteshopper_s1.jpg title subtitle text image POWER... IS EXPENSIVE! 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! /media/museum/pubs/imsai_8080_pub_2.jpg title subtitle text image NOT REALLY AN IMSAI! 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). /media/museum/pubs/imsai_8080_pub_3.jpg title subtitle text image ADVERT FROM NEW ZEALAND In November 1976, the assembled basic version cost A$931, the unassembled version cost A$599. Thanks to **Murray Moffatt** from New Zealand /media/museum/pubs/imsai_8080_pub_s4.jpg title subtitle text image F.D. SYSTEM 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** /media/museum/hardware/altair_8800_fd_1.jpg title subtitle text image ADVERT DATED SEPTEMBER 1976 - PROM board\ - TV Dazzler video card\ - Analog I/O board\ - Cyclop optical digitalizer null title subtitle text image US ADVERT (1977) 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. /media/museum/hardware/cromenco-joysticks_pub_1-1977.jpg title subtitle text image ADVERT (NOVEMBER 1976) null title url platform text Altair and IMSAI Emulators http://www.threedee.com/jcm/emu8080/index.html Windows Altair 8800b and the IMSAI 8080 emulators for Windows title url platform text Altair32 Emulator Project http://highgate.comm.sfu.ca/~rcini/classiccmp/Altair32.htm Windows Windows emulator based on the original emulator of Claus Giloi title url text IMSAI.NET http://www.imsai.net/ Where you can buy a 20 Mhz. Z80 version of the 8080! title url text oldcomputers.net http://oldcomputers.net/imsai8080.html Nice page with beautiful pictures title url text When PCs where Micros http://rwebs.net/micros/Imsai/Default.htm Nice original IMSAI brochure put on the web title url text www.obsoletecomputermuseum.org http://www.obsoletecomputermuseum.org/imsai/ nice detailed IMSAI page author date text GOplayer (USA) Wednesday 19th September 2018 I was lucky enough to buy the IMSAI 8080C computer at a computer business that had an auction after the owner passed away for $14. ! It works great but I couldn''t bid on the two 8"floppy drives because the $14. was all I had! I begged the auctioneer afterwards for the drives as they didn''t sell, but he wouldn''t relent... My unit needs 3 switch covers(orange/blue) as I accidentally knocked them off... I have them somewhere. The computer is immaculate and works as if new,(love the robustness of older technology electronics). One big TO-3 voltage regulator(5V?) on the back wall on a aluminum 90 degree fin in front of the fan and two big capacitors(electrolytic) in the front in the voltage supply area on the right, walled off by aluminum shield from the S-100 bus slots on the left. The CPU is white w/gold cap. Such a joy to see it operate on the front panel as I load address and data registers(8 bit)using the switches in single step load/review mode. Then I flip then switch for Run and toggle the start switch and watch the digital light show as it computes, branches, adds and moves REAL Binary Data around before I hit the start/stop toggle switch or it reaches a halt in the program. I need to make a digital video of it in action someday. It is still a joy to operate, setup, run and observe the data in red Light Emitting Diodes(LEDs). This was one of the first times we could SEE our data bits and computing in action. I was a programmer in the Air Force on 64-bit machines in the early 70''s... COBOL, PL/1, RPG, FORTRAN and assembly. This machine is a museum piece that STILLl functions as it was designed. I had a few Timex Sinclair''s as well. Also great inexpensive machines for their day. Clive Sinclair was a mathmatician and it is reflected in the tight byte codes of his BASIC language computers for the masses. They are great as 8/16 bit scientific BASIC computers, not just for gaming, which is fun, and drove the computing industry to where it is today. Steve Ingham 9-19-2018 author date text Lorno (Calgary, Canada) Saturday 12th November 2022 I bought my IMSAI 8080 as a kit back in 1976. By 1979 I had it feeding a Heathkit H9 terminal and was running Northstar Basic. Writing and running Basic Code LOL. Everything is still downstairs in my basement in boxes, although I havent fired them up since 1983. author date text Edward Kenny (Huntsville, AL USA) Thursday 29th September 2011 I used a couple of IMSAI 8080''s at NASA in the early 1980''s. Each had a Z80 4MHz CPU and 64KB of RAM. For storage each had a dual set of 8-inch floppy drives. Each also had a 5MB hard drive but were never used much because they were not very reliable and eventually failed. author date text Fubeca6 Saturday 21st August 2010 Raindance Rob - it was indeed used in War Games (check out Fire in the Valley by Paul Freiberger and Michael Swaine) author date text Raindance Rob (UK) Saturday 31st July 2010 looks like what David played by Matthew Broderick used in the film Wargames, can anyone confirm ? author date text Thomsonicus (Poland!) Wednesday 17th January 2007 now that's what I call oldschool! Respect to all who have been using this piece of fine equipement author date text ian osgood (Portland, OR) Thursday 4th March 2004 I learned BASIC and 8080 assembly as a wee lad on one of these. It was owned and tricked out by a housemate, Gail Marshall. He wrote his own keyboard drivers and graphics libraries (so he could do the Game of Life) as well as an implementation of LISP. He hacked an Olivetti daisy-wheel typewriter into a printer! Gail was truly a Real Programmer. We still have a box of 8" disks around somewhere... /museum/mits-altair-8800 389 url date https://web.archive.org/web/20230328234541/http://www.old-computers.com/museum/computer.asp?c=389 2023-03-28

After seeing the instant success of the 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)