Multiprise 3000

IBM's Multiprise 3000, product number 7060, is physically the smallest mainframe, introduced in 1999. 

This kind of mainframe used an OS/2 workstation with an special OS/2 software (Support Element) to administrate some functions (power) of the mainframe.

Models:
 * 7060-H30
 * 7060-H50
 * 7060-H70
 * 7060-P30

Links

 * Video: Booting MP3000 - Showing OS/2 Warp to boot the Mainframe
 * IBM Announcement Letter