folkert/python-pdp1170
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

MARK

Browse source
This commit is contained in:
Neil Webber 2023-10-16 09:09:54 -05:00
parent af5bca7ae1
commit 11dffdb199
1 changed files with 8 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
op00.py
View file

@ -229,7 +229,13 @@ def op00_63_asl(cpu, inst, opsize=2):
def op00_64_mark(cpu, inst):
raise ValueError
# this instruction is... what it is. Note: if I/D separation
# is enabled, the stack must be in BOTH D and I space, as control
# will be transfered to the stack (typically) for this instruction.
nn = inst & 0o77
cpu.r[cpu.SP] = (cpu.r[cpu.PC] + (2 * nn)) & cpu.MASK16
cpu.r[cpu.PC] = cpu.r[5]
cpu.r[5] = cpu.stackpop()
def op00_65_mfpi(cpu, inst, opsize=2):
@ -243,7 +249,7 @@ def op00_65_mfpi(cpu, inst, opsize=2):
# There are some wonky special semantics. In user mode if prevmode
# is USER (which it always is in Unix) then this refers to DSPACE
# (despite the MFPI name) protect the notion of "execute only" I space
# (despite the MFPI name) to protect the notion of "execute only" I space
prvm = cpu.psw_prevmode
curm = cpu.psw_curmode