IBM 5363 System/36
The 5363 was introduced in 1987 as a replacement for the 5364 Baby 36. The RICM has a 5363 II, 5363 III, and a 5363 IV.
We powered on one of the 5363-III systems and actually got a Sign On screen. It looks like the last time that it was IPLed was in 1994. That says a lot about the reliability of a system that has been powered off for 17 years. If we can figure out the administration userid and password we will have a demonstratable system.