|- align="center" | | |10 |Decimal overflow |2 |- align="center" | | |11 |Decimal divide |3 |- | |- align="center" |FP |1 |12 |Exponent overflow |0 |- align="center" | | |13 |Exponent underflow |1 |- align="center" | | |14 |Significance |2 |- align="center" | | |15 |Floating-point divide |3 |} Job programs All job programs run in S/360 problem state, may run with virtual addressing enabled or disabled, and may or may not be reentrant (more than one instance of the job program may or may not be allowed to execute). With multiprocessor configurations a single job will only execute on a single processor at a time, but the supervisor may assign a job to different processors at different times. The MTS job program is the one with which most users interact and provides command interpretation, execution control, file and device management, and accounting services. Other job programs assist the supervisor (the Paging Device Processor or PDP, the OPERATOR console job, the Disk Manager or DMGR, ...), provide common or shared services (spooled local and remote batch services via HASP and the HASPlings or later the Resource Manager or RM which was developed at the University of British Columbia to replace HASP), or allow the system operators to display status and otherwise control the system (JOBS, UNITS, STOP, BLAST, GOOSE, STARTUP, SHUTDOWN, REW, WTM, ...). New jobs, other than the very first job, are started by requests to UMMPS from other jobs, most often the OPERATOR job. The very first job, INIT, is started immediately after IPL and supervisor initialization. 24-, 31-, and 32-bit addressing From their start and for much of their lifetime UMMPS and MTS operated using 24-bit addressing. UMMPS never used the 32-bit virtual memory addresses that were available on the IBM S/360-67. In August 1982 the University of Alberta changed UMMPS to operate in 31-bit addressing mode to allow more than 16 MB of real memory to be used, although real memory above 16 MB was only used for to hold virtual memory pages. Job programs and user programs continued to use 24-bit addresses. In 1985 Rensselaer Polytechnic Institute (RPI) made changes to UMMPS to support S/370-XA which among other things allowed either 24 or 31-bit addressing for job programs and for user programs running under MTS. Changes were made at the University of Michigan in 1990 to allow user programs using 31-bit addresses to work