It was 8 MHz faster than its predecessor, the PowerBook 145B. It lacked an ADB port and used a lower-quality passive matrix display than other contemporary offerings, both to reduce the price. It also lacked external monitor support. Like the Duos and the PowerBook 100 before it, the 150 only had a single serial printer port, however, a third-party adapter was available for use in the optional modem slot.
Though it used the 140 case design, its internals were based on the PowerBook Duo 230 and actually more similar to the features of the PowerBook 190 (which used the PowerBook 5300's case design). Notably, this new logicboard design allowed this 100 series PowerBook to use more than 14 MB RAM for the first time. It was also the first of the 100 series to include a lithium-ion backup battery to preserve RAM contents when the battery is replaced, as well as the first Macintosh ever to use less expensive and larger IDE drives (formatting required a unique software application limiting the selection of compatible drives). This was the last PowerBook model to include a trackball. Like the 145B it replaced, the 150 could not be used in SCSI Disk Mode, unlike the Duo, 190 and 5300 which had HD Target Mode implemented.