Imsai VDP-80
[Vin112]
The IMSAI VDP-80, released in 1977, was a pioneering all-in-one microcomputer notable for integrating a 3 MHz Intel 8085 processor, 32K or 64K RAM, dual 8-inch floppy drives, a 12-inch video display, and a full alphanumeric keyboard with advanced features like N-key rollove all within a single desktop cabinet. Its claim to fame was being among the first microcomputers shipped fully assembled and ready to use, targeting small businesses and professional users at a time when most systems were sold as kits, and it came bundled with IMDOS (an enhanced CP/M variant) and BASIC, making it a turnkey solution for data processing and business applications. Although technologically advanced, the VDP-80 (Video Display Processor) was expensive and heavy, and its popularity was limited compared to emerging competitors like the Apple II and TRS-80; IMSAI’s bankruptcy in 1979 marked the end of its brief prominence.
- Manufacturer: IMS Associates, Inc., later known as IMSAI Manufacturing Corp, based in San Leandro, California
- Type: All-in-one desktop computer
- Release Date: 1977
- Cost at release: USD $6,995 (CAD ~$36,000 adjusted for inflation)
- MIPS: 0.3 (300 KIPS)
Hardware Specifications
- CPU: Intel 8085 microprocessor, 3 MHz
- RAM: 32K or 64K RAM (expandable)
- Storage: Dual 8-inch PerSci floppy disk drives (double density)
- Display: 12-inch CRT video display 80 columns × 24 lines
- Keyboard: Integrated alphanumeric 62-key main keyboard
- 7-slot motherboard for expansion
- Serial and parallel I/O ports (printer/modem support)
- Heavy-duty power supply
- Built-in IMDOS operating system (CP/M variant), with BASIC and FORTRAN IV support
- Fully assembled desktop cabinet
- Weight: 46 kg (103 lbs)
Operating System & Programming Languages
- OS: IMDOS, a multi-disk operating system that was IMSAI’s enhanced and customized version of CP/M, supplied with every system
- Programming Languages: BASIC (interactive and compiler versions, such as BASIC-E and CBASIC), FORTRAN IV (Level 2 ANSI compiler), Assembly language (8085 assembler and dynamic software debugging tools), Additional utilities for software development and diagnostics were included with IMDOS
Notables
- It was one of the first fully assembled, turnkey microcomputers aimed at business and professional users, integrating CPU, RAM, dual 8-inch floppy drives, a 12-inch CRT, and a sophisticated keyboard in a single desktop cabinet.
- The VDP-80’s CPU was the Intel 8085 which was Intel’s second generation of CPU’s; in 2025 Intel has released it’s 15th generation CPU
- The IMSAI VDP-80 could dynamically switch its floppy disk controller between single and double density to support multiple IBM disk formats simultaneously, a rare feature for its time.
- The VDP-80 could serve as an intelligent terminal for distributed data processing or as a standalone business computer, making it versatile for both local and remote computing tasks.
- The VDP-80 was sometimes called a “Video Data Processor,” highlighting its integrated display and data processing focus.
- Despite its technical strengths, the VDP-80 sold poorly due to its high price and heavy weight, and it was quickly outpaced by more affordable and user-friendly competitors like the Apple II and TRS-80.
- IMSAI as a brand is legendary in the vintage computing world because the earlier IMSAI 8080 was the first major “clone” of the Altair 8800, helping to establish the S-100 bus as a microcomputer standard and making personal computing more accessible.
- The IMSAI 8080 famously appeared in the movie “WarGames” (1983), cementing its place in pop culture and inspiring a generation of computer enthusiasts.
- IMSAI’s pioneering use of CP/M (and later IMDOS) contributed to CP/M’s rise as the de facto standard operating system for early microcomputers
Donated by: Arlen Michaels