Date: 1975. From the IBM History website: "One of the first 'portables' on the market, it can store more information than any other commercial machine (48,000 bits), contains a small display screen, and can be used as a terminal for the System/370. More 'luggable' than portable, it weighs 50 pounds and costs from $9,000 to $20,000."
Other specs: 5-inch 16x64 monochrome monitor, 16K-64K main memory, 204K quarter-inch tape cartridge; available operating systems: APL, BASIC, or both (selectable by toggle switch on front panel). Nicknamed SCAMP (Special Computer, APL Machine Portable). We had several of these in Watson Lab — in those days, APL was a prestige language and these were our first desktop computers.
Photos: IBM archives.