IBM Portable PC 1978
Introduced in February 1978, the IBM 5110 replaced the fist commercially available portable computer – the IBM 5100. It came in three models, ingeniously designated model 1,2 and 3. Model one had a 204kB QIC tape drive, model two made do without one, and model three which was sometimes called the IBM 5120, has 2 x 8″ floppy disks of 1.2MB each. The model three was called a desktop computer, so shouldn’t be included here. Ugly beast.
It was also one of the earliest computers to support IEEE-488, RS232 and floppy drives. The processor was a device IBM called PALM – which stood for “Program All Logic in Microcode”. It was an entire circuit board containing 13 square metal-can bipolar gate arrays, 3 conventional DIP transistor-transistor logic (TTL) parts and 1 round metal can part – so it was not a ‘microprocessor’ in the sense we use it today.
The IBM 5110 could store as much as 204,000 bytes of information per tape cartridge or 1.2 million bytes on a single diskette.
Rather fantastically you could switch between APL and BASIC using a toggle switch.