Kaypro IV Portable Computer

Kaypro was a manufacturer of portable microcomputers running the CP/M operating system. Its first commercial model, Kaypro II, was launched in 1982. The Kaypro IV was introduced in 1983. Surprisingly, it is not the same as the Kaypro 4, which was released in 1984.
The Kaypro IV was basically a Kaypro II with added Double Sided/Double Density Drives. It had a Z80 microprocessor that ran at 2.5 MHz. The memory included 64 KB of RAM and 2 KB of ROM. Kaypro IV had a 9" monochrome monitor and a built-in speaker. The operating system was CP/M 2.2. The Kaypro IV included the word processor Wordstar, which was included in the Perfect Software Suite.
The introduction of the IBM PC in 1981 led to the rapid growth in popularity of the MS-DOS operating system for personal computers. Software developers migrated to writing for MS-DOS instead of CP/M. Kaypro was slow to make the transition in their machines, and the company never gained the kind of prominence in the MS-DOS arena that it had enjoyed with CP/M. A prime competitor for the MS-DOS portable market was Compaq, which sold an "all in one" computer that was similar to its own CP/M portable. In March 1990 Kaypro filed for bankruptcy.
This Kaypro IV was purchased with funds from a research grant obtained by Robert M. Smith, of the Department of Space History of the National Air and Space Museum. Smith's book, The Space Telescope, was written in part on this computer.
Currently not on view
Date made
Kaypro Corporation
Physical Description
metal (overall material)
plastic (overall material)
overall: 21.5 cm x 48 cm x 43 cm; 8 7/16 in x 18 7/8 in x 16 15/16 in
ID Number
catalog number
accession number
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Medicine and Science: Computers
Computers & Business Machines
Family & Social Life
Data Source
National Museum of American History, Kenneth E. Behring Center


While on active duty USN at Navy AccountING and Finance Center in Washington DC. I requisitioned three of these computers to asses for use at all disbursing offices within the Navy.
"Kaypro introduced at the 2nd annual Computer Show (SF convention center) with a rushed prototype so that the Osborne 1 (which had publicity prior to the show) was not the only 'portable pc' shown to the 10,00 attendies. It pre-dated the ill fated first IBM pc by at least 2 years and was well established in the SF bay area by the time IBM had a real sales model that the public liked. Another note was the perfect software suite included a WP program but Wordstar was sold for nearly every CP/M manufacturer and was FAR more popular (hence the shortcut keys still in use today like ^c, ^v etc). As sales increased they OFFERED wordstar for the kaypro's and was not part of the INCLUDED bundles. I build my first cp/m system starting in 1979 - and worked for several of the pc stores and shops starting in 1980-81. Among the stores were the Digital Deli (mt view - which sold Lee Felenstiens SOL, Apple(s), Osborne, Northstar, Compupro and Cromemco's Morrow Micro Sys and a huge lot of other stuff) and Don's Cupertino computer shop (kaypro, Sequoia and Compaq dealer). My last s-100 was the CCS (calif computer systems) z80b as its bios and compiled core allowed it to use the Morrow multi-disk reading ability for (most) all size related disks.. Alas I gave that system to a high school in the mid 90's. but I do have Many boards disks and systems today. Of real note is FEW cp/m systems prior to 1980 were 'made' with boards and kits averaging at least 50 to one (I got started by FIXING pc boards that individuals soldered up themselves trading my labor for parts/code and help with my first systems). Yes I have some club (sunnyvale computer club which included woz, Lee and others that went on and up) and many many disks boards, even kits never built. In 1979 s-100 had just overtaken the s-80 buss stuff finally (introduced in 75 I think). FYI - lived in Los Altos and worked at AMD on silicon drive (when they had 1 building). Early club meetings were at Dysan auditorium SJ later at HP auditorium (next to stanford).. Palo ALto?In the hills. "

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