IBM's mini computerslack thereof 823

It seemed, for a long time, that to IBM the only input device was some kind of card reader and the only output device was some kind of card punch or line printer. Consider their Selectric-based terminals. To read from the terminal they would unlock the keyboard, comparable to giving a card reader a read command, and then the user got to type on the keyboard, and when the user hit carriage return they would take that as the end of the card and lock the keyboard again. Whereas the minicomputers buttumed something like a Teletype terminal and worked character-by-character from the ground up.

However, to give credit where it is due, IBM did have a process control version of the 1620, of all things, and later a process control version of the 1130 that was essentially a minicomputer.

I wrote a piece once about how to tell the difference between a computer and a minicomputer. (Was the 360-40 a minicomputer? It had a 16-bit memory word.) The way you tell the difference is: you ask for a manual for the computer. If they give you a manual, and then you buy the machine, and after that they make you pay for the manuals, it is a minicomputer. If they make you pay for the manual, and then you buy the machine and after that the manuals are free, it is a computer. --

jhhaynes at earthlink dot net