IBM's very first "transportable" computer was an "IBM 1401", transportable by truck (called DataMobile).
The IBM 5100 is equipped with a 16-bit processor module called: PALM (Put All Logic in Microcode). The system had a weight of about 25 kg with the size of a small suitcase, supplied with a carrying case (hence portable).
A portable system with a large amount of RAM and ROM, including a CRT display and tape drive. A considerable achievement for the time (1975)!