IBM 5120

The IBM 5120 Computing System (sometimes referred to as the IBM 5110 Model 3) was announced in February 1980 as the desktop follow-on to the IBM 5110 Computing System. It featured two built-in 8-inch 1.2 MB floppy disk drives, 9-inch monochrome monitor, 32K RAM and optional IBM 5114 stand-alone diskette unit with two additional 8-inch 1.2 MB floppy disk drives. The system was sold with both APL and BASIC languages in ROM and provided a toggle switch on the front panel to select the language. APL allowed numerous business software written on IBM minicomputers to run on the 5120. Other computer data storage products were available from Core International, Inc for these machines.

Aside from larger screen size and performance benefits over its predecessor, the IBM 5120 design incorporated several usability advantages: