gtpm1m1n | TPF V4R1 Migration Guide: 3.1 to 4.1 |
There are several changes to the control program environment in the TPF
4.1 system:
- All control program code must run in 31-bit mode.
- The control program processes using format-1 channel control words (CCWs)
and supports CCW indirect data
addressing (IDAW) use. If you have your own control program channel
programs or modify those provided by IBM, you must use format-1 CCWs, real
addresses, and be aware of the 4 KB data page boundaries (or use
IDAWs).
- The control program processes with the dynamic address translation (DAT)
facility on.
- The control program processes with low address protection on. See Modifying Low Storage for more information.
- The control program processes masked for input/output (I/O)
(except at the top of the CPU loop and for fast-link macro services).
- CPU timer interrupts occur at the rate of 100 per second. (TPF
3.1 timer interrupts occurred at the rate of 20 per second.)
- The control program can write directly to a real-time tape (RTT) using the
new $TCPLC macro. (You needed an ECB to do this in the TPF 3.1
system.)
- The control program can write directly to an operator using the WTOPC
facility.
(You needed an ECB to do this in the TPF 3.1 system.)