The IBM PS/2E on top of a Model 56 and Model 30-286.
|Release date||July 29, 1993|
|Units sold||Around 25,000|
|Media||1.44MB 3½-inch floppy disks|
|Operating system||IBM DOS 5.02 or 6.1, Windows 3.1, Windows 95, OS/2|
|CPU||IBM 486SLC2 clock doubled 50/25MHz processor|
|Storage||120-340MB hard drive|
|Input||Track Point II Keyboard, Mouse (optional), Touch screen|
|Power||Internal PSU @ 24 watts|
|Dimensions||304.8 x 304.8 x 69.6mm|
|Related articles||IBM Personal System/2|
The IBM Energy or PS/2E (IBM 9533) is an IBM Personal System/2 computer. It was the first Energy Star compliant personal computer and featured very low power consumption (compared to other computers of its time) and made extensive use of recycled materials during the manufacturing process.
The PS/2E featured a 486SLC2 50/25MHz with 16 kilobytes of L1 [CPU cache] allowing the CPU to execute instructions at twice the 25MHz bus speed while required instructions and data reside in the cache. No external L2 cache was designed on the motherboard however; so the machine relies on its 16 KB of L1 cache for performance. With an ISA bus, it accepts a single ISA option adapter with the use of a riser card. Depending on the sub-model number, it came supplied with either a special option adapter for four PC card PCMCIA slots, or as a diskless workstation with an ethernet or token-ring adapter.  Additional options included several PCMCIA cards, a color LCD screen, and a color LCD touch-screen with a special version of OS/2.
The environmentally friendly PC borrowed some components from the ThinkPad line: including the Floppy Diskette Drive and the Hard Disk Drive, and was composed of recycled plastics designed to be easily recycled at the end of its life. The internal power supply would only consume a maximum of 24 watts and operated without the need of a fan completely passively cooled. 
The PS/2E featured a full-sized internal PC Speaker, two SIMM sockets and an extended bank of memory soldered directly to the motherboard. It featured 1 MB of onboard graphics memory for the XGA-2 implementation which was linked to ISA instead of MCA. Like all Personal System/2 computers, if a change in hardware is performed the configuration must be updated with the use of the reference diskette (for example changing the memory size).
- Ohland, Louis. "9533 (PS/2e)". Retrieved 20 June 2014.
- "Personal Systems Reference IBM PS/2 1992 to 1995 - withdrawn" (PDF). http://www.lenovo.com/psref/. IBM PC Institute. Retrieved 20 June 2014.