On July 28, 1981, IBM (International Business Machines Corporation) revealed its first desktop computer, System/23 Datamaster, a demonstration of IBM’s efforts to shrink the size and cost of computing.
Today’s (July 28) story of what happened this day in Science, Technology, Astronomy, and Space Exploration history.
IBM System/23 Datamaster
IBM System/23 Datamaster was an all-in-one computer with a text-mode CRT display (cathode-ray tube, similar to the “picture tube” in a television receiver), keyboard, processor, memory, and two 8-inch floppy disk drives in one cabinet.
The computer combined word processing and data processing in a small machine. It offered a choice of two printers, up to 4.4 megabytes of diskette storage, along with Business Management Accounting and Word Processing programming.
The introductory price of the computer was US$9,000 (equivalent to about $27,000 in 2022), making it IBM’s lowest-priced small business system to date.
The production was discontinued in 1985.
But, it was the IBM Personal Computer, announced in August 1981 (and its descendants) that started the PC revolution: IBM PC took the features and characteristics of all these early small computers and provided them in one incredibly utilitarian machine.
IBM PC was far less expensive and far more popular.

IBM System/23 Datamaster specifications
- Operating system: BASIC built-in
- CPU: Intel 8085 @ 4.77 MHz
- Memory: 64 KB RAM (expandable to 128 KB), 112 KB ROM
- Storage: Two 8-inch floppy disk drives
- Display: Green phosphor CRT display (80×24 text)
- Input: Model F keyboard
- Mass: 95 lbs (43 kg)
As you can see, the 8-inch floppy drives were very large, with several heavy-duty components. These large and heavy drives are rather uncommon for 1981 – most other computer systems had switched to 5 1/4-inch drives by this time.
Sources
- IBM System/23 Datamaster on Wikipedia
- IBM System/23 Datamaster on the IBM official website
- IBM System/23 Datamaster on the Old Computers website
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One reply on “System/23 Datamaster, IBM’s first desktop computer was revealed on July 28, 1981”
Hello,
The data about this computer is factually wrong.
The it is true that its CPU is a 8085, but it is clocked at 6.14MHz (3.07MHz effective). DRAM was offered from 32KB to 128KB in increment and while the banking mechanism allows 256KB the handshaking mechanism only allows 128KB.
You can refer to this article to correct this and other data, as well as ampliate your article (https://bitspassats.com/index.php/IBM_System/23_Datamaster).