Save Registers

The SAVREG routine saves assigned registers between executions of the assembly language portions of the simulator. (See also RESREG, FETCH and STORE.) The register save area is available to the FORTRAN code which freely reads and modifies it.

SAVREG   PS
          BX6    X3
          BX7    X4
          SA6    MA
          SA7    A6+B1
          BX6    X5
          BX7    X0*X2
          SA6    A7+B1
          SA7    A6+B1
          BX6    X2
          AX6    12
          SA6    A7+B1
          SX6    B2
          SA6    STEP
          EQ     SAVREG

The registers are stored into sequential locations within a common block of memory.

          USE    /REGS/
SR       BSS    1
MA       BSS    1
MD       BSS    1
PC       BSS    1
AC       BSS    1
LK       BSS    1
MQ       BSS    1
STEP     BSS    1
          USE    *

PDP-8 Simulator