The IBM 5100 was a portable data-processing workstation available in 1975, which was based on the 1973 IBM SCAMP project [video]. This included a tape cassette storage, up to 64KB RAM, supported both BASIC and APL programming, with an integrated 5″ CRT screen and keyboard. This was all available in 1975, the same year as the Altair 8800 kit. While the Altair kit was around $500 (with no keyboard or monitor or storage device), the IBM 5100 was priced about $20,000 (in 1975 dollars) as a ready-to-go product with a large suite of software.
In 1978, IBM released an updated version called the IBM 5110: the tape cassette interface was no longer standard (an external tape or floppy disk drive were offered options). But essentially the same “A1″ motherboard, PALM processor, power supply, and 5” screen as the 5100 were used. The base price of the 5110 was around $11,000. One cosmetic difference was that the 5110 has a black front face around the keyboard, whereas the 5100 has white.
Was the IBM 5100 the first Personal Computer?
The short answer is No. But it is certainly amongst one of the earliest.
There is a broad spectrum between the DEC PDP-1 of 1960 up to the IBM 5150 PC of 1981 that have been proposed as the “first” Personal Computer. And all these honorable mentions are generally valid at being the first at some kind of innovation along the way towards what became the Personal Computer.
The following mural is my depiction of the transition from minicomputers to microcomputers.
OldComputers.Net (here) is an excellent archive of many personal computers since 1970.
The IBM 5100 was one of several early personal computer systems. It wasn’t “personal” in the sense that you’d just go to a store and buy one. It would be ordered from IBM, and cost about as much as a very nice car, but less than a house at the time of its production. But once the IBM 5100 arrived, it was fully functional as a personal computer – to program in whatever you desired, without having to remote to any mainframe. It had a multi-line screen, full size keyboard, tape storage, a decent amount of RAM (8K to 64K), and could run some existing IBM System/370 or IBM System/3 software (since it incorporated the APL or BASIC of those systems).
The Wang 2200 of 1973 was probably the most equally capable system of that time (and there is a story that a Wang 2200 was rolled into an IBM VP’s office, as proof that the concept of a microcomputer was possible). The main difference is the Wang had an external PSU and processor, making it a far less portable system (and the Wang had their own BASIC, which had some quirks due to how it was implemented). But the Wang 2200 had a larger screen and was very effective as a desktop publishing system.