The System/360 was supplanted by the System/370.
- The 360 is a 32bit machine
- 16 general purpose 32-bit registers, 0 to 15 (usually Equated to the labels "R0" through "R15")
- 4 floating point 64-bit registers numbered 0, 2, 4 and 6, and
- a Program Status Word (PSW). The program status word is composed of the privileged bit, the program counter, and the memory protection key.
The 360 is a BIG endian machine, with values stored as high to low.
I don't think there is any direct S/360 emulators out there... However I'm pretty sure that Hercules will run System 360 software as the 370 is upwards compatible with the 360.