The real first IBM PC: The (almost portable) IBM 5100 !
Monday, January 21, 2019, 11:11 PM
Posted by Administrator
Most of us can't remember this "PC" (no, not an Intel PC, of course).
But it even has elements (parts) which are similar to the first IBM PC (e.g. the power switch).
In 1973, a prototype for programming APL was build, named SCAMP.
IBM developed it further to the Model 5100 (followed by 5110, 5120).
It already had a 16bit "CPU" (in fact, the CPU is a module with more than one IC), which addressed 64KB RAM, and had also a kind of bank switching for accessing memory (like the later CP/M 3.0 computer).
I am fascinated about it's mass storage (a QIC magnetic tape) and it's professional finish (... what else do you expect from IBM in 1975 ?). Beside APL, it can be programmed in machine language and of course in BASIC (not Microsoft BASIC !).
This is an advertisment which praise the systems versatily and obvious portability (24Kg) ;-)
Interestingly, the first IBM PC got the model number 5150... also not by accident.
Last but not least, a popular japanese anime series and movie and also a well known video game for several game consoles named "Steins;Gate" has also an IBN 5100 (sounds similar, eh) as a guest star. See here: