IBM strongly supported APL and developed a small computer that included APL. Introduced in 1975, the 5100 was IBM's first portable computer, arriving six years before the PC! Describing it as portable is a bit of a stretch because it weighed around 50 pounds.

The 5100 had an integrated CRT display, keyboard and tape drive. The CRT was a 5 inch (diagonal) screen which displayed 16 lines of 64 characters. Because the characters were so small, IBM provided a three-position switch that allowed the user to display all 64 characters or only the leftmost or rightmost 32 characters interspersed with blanks. RAM could be expanded to 64K. A dot matrix printer, external tape drive, communication adapter, and serial I/O device were available options.

The 5100 supported two programming languges: APL and BASIC. The user could select the language via a toggle switch on the front panel of the computer. GSM acquired a 5100 in the summer of 1977 and selected APL, which it was already using, as the language of choice.

Because of its weight, the IBM 5100 at GSM was securely mounted on an orange wheeled cart so that it could be moved freely in and out of offices and classrooms for use and demonstration. It is not so mounted in the photo below.


Photo held in IBM Archives