The PowerBook 150 was a laptop created by Apple Computer in 1994. It was the last member of the PowerBook 100 series to use the original case design, the most affordable of the series when introduced, and also the last consumer model. 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 current offerings, both to reduce the price. Like the Duos & 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. For those users requiring an external keyboard or mouse, this made a serial option a practical consideration. It also lacked a rear port door, unlike the rest of the 100 series models. 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 14MB RAM for the first time, 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). 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. This is the last PowerBook model to include a trackball. However, 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.