Series of portable computers, from Commodore, introduced in 1983. The first machine was called Commodore SX-100, but it eventually became Commodore SX-64, aka Commodore DX-64 (same machine, two floppy drives).

Basically, these machines were Commodore 64s in a portability-enhanced chassis, no Datassette port, and built-in floppy drive and CRT (yes, youngsters, back then LCD displays were a myth!) OS was hacked a bit: Screen colors were different, the startup messages were different and loading defaulted to device 8.

Note the subtle naming... Commodore obviously knew that laptop machines would have a market!

See also: Osborne 1