The PowerBook 145, manufactured by Apple Computer, was a speed-bumped PowerBook 140, increasing the processor speed from 16 MHz to 25 MHz. The standard hard drive was upgraded from 20 MB to 40 MB. The 145 also introduced a new feature for the battery-conscious: users would be able to program the 145 to sleep or completely shut down whenever the clamshell unit was closed. Though a direct descendant of the 140, the 145 was actually the replacement for the PowerBook 100 as the low-end model, the 140 having been superseded by the new mid-level 160. It was replaced by the PowerBook 145B in June 1993. The only codename for this model is: Colt 45.