IMSAI VDP-44
Released:1978
Price:US$4,995 (w/32K)
CPU:Intel 8085 @ 3MHZ
RAM:32K or 64K standard
Display:9-inch CRT, 80x24 text
Ports:RS-232 serial, parallel ports
Storage:Two 5 1/4-inch floppy drives
OS:IMDOS (CP/M)
2K ROM "monitor"



IMSAI made a moderately successful computer business with their IMSAI 8080 S-100 computer, released in 1975. It can be considered a small business or hobby computer.

In an effort to expand into the serious business market, the IMSAI VDP-80 (Video Data Processor) was released in 1977. It is a large and heavy all-in-one computer system, containing a 7-slot S-100 motherboard, 12-inch CRT video screen with a full-size keyboard, and a dual 8-inch floppy drive. Altogether this monster weighs over 100 lbs (45kg), and takes up 25x25-inches (64x64 cm) of desk space.

Although initially selling quite well, this new $6,745 (w/ 64K RAM) business machine was reported to be plagued with problems, which includes the state of the art but notoriously unreliable PerSci floppy disk drive, which needed constant realignment.

The next year, in 1978, IMSAI released an improved model, the VDP-40. At only $4,495, this model has a smaller 9-inch CRT, and now utilized industry-standard 5 1/4-inch floppy drives. Instead of the blue molded fiberglass body of the VDP-80, the VDP-40 has a cheaper metal body and framework. Additional models include the VDP-42, and VDP-44, but the only difference is that they have higher capacity floppy drives. Weighing only 65 lbs, the new systems were smaller, lighter, cheaper, and more reliable.

Model Price (32K RAM) DisplayFloppy drives
 VDP-80 (1977) 
$5,995
 12-inch CRT  One PerSci 2x512K dual 8-inch 
 VDP-40 (1978)
$4,495
 9-inch CRT Two SS-SD 90K 5 1/4-inch
 VDP-42 (1978)
$4,695
 9-inch CRT Two SS-DD 200K 5 1/4-inch
 VDP-44 (1978)
$4,995
 9-inch CRT Two DS-DD 360K 5 1/4-inch


IMSAI VDP-44

IMSAI VDP-44

All of the VDP-4X systems are the same, except for different capacity floppy drives. The fake wood paneling is classic 1970s.

The top (normally screwed down) lifts up like a car hood, for easy access to all of the internal, including the 10-slot S-100 card cage, which contains 4 or 5 S-100 cards, comprised of:
  • MPU-B CPU card
  • VIO-D video controller
  • RAM-III 32K or 64K RAM memory card
  • one MDIO or two DIO-D cards to control the floppy drives

    • All of the IMSAI computers ran the IMDOS operating system - a modified version of the CP/M disk-based operating system created by Gary Kildall of Digital Research. IMS had approached Gary Kildall and paid a fixed fee of $25,000 for non-exclusive CP/M license, which would eventually become the de facto standard personal computer operating system throughout the 1970s and early 1980s.

    Soon enough, due to competition, and possibly the bad reputation of the VDP-80 series, demand for IMSAI products went into a decline.

    By 1979 IMSAI corporation was bankrupt, and was sold to former early employees of IMS Associates, Thomas "Todd" Fischer and Nancy Freitas (now known as IMSAI.net), but IMSAI founder William Millard's other business - ComputerLand, at the time the nation's largest computer retail chain - had grown into over 800 franchises, and Millard became a "computer billionaire".

    In 1985, a court jury ruled that Millard must give up 20 percent of ComputerLand, which had reached over 1 billion dollars in revenue, as repayment for a $250,000 loan he received in 1976, when the ComputerLand chain was getting started.

    Apparently to avoid settlement payments, fines, and taxes, Millard fled to Saipan in the western Pacific Ocean, which is when Millard sold ComputerLand for $200 million.

    At some point, Millard then moved to the Cayman Islands, a notorious tax haven, just south of Cuba.


    Related Links

  • VDP-40 advertisement from Computerworld June 5, 1978
  • IMSAI-based computers from retrotechnology.net
  • VDP-40 flyer from CLASSIC TECH
  • "Once Upon a Time in Computerland: The Amazing, Billion-Dollar Tale of Bill Millard"
  • ComputerLand CEO Seeks Creditor Protection Amid Tax Fight
  • IMSAI history from Stand Viet's PC-History
  • Fire in the Valley book excerpt



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