45 lines
1.6 KiB
Python
45 lines
1.6 KiB
Python
def boot_hp(p, addr=0o10000):
|
|
# this is the sort of thing that would be keyed in from
|
|
# the console switches (if the machine was not equipped
|
|
# with a boot rom option to hold it instead)
|
|
#
|
|
# It is a minimalist program, with lots of assumptions, to read 1K
|
|
# from block zero of drive 0 into location 0. The execution start
|
|
# at zero is done elsewhere.
|
|
#
|
|
# NOTE WELL: THIS ASSUMES THE MACHINE IS IN RESET CONDITION WHICH
|
|
# MEANS MANY OF THE DEVICE REGISTERS ARE KNOWN TO BE ZERO
|
|
#
|
|
# MOV #176704,R0 -- note how used
|
|
# MOV #177000,-(R0) -- word count - read 1K though boot really 512
|
|
# MOV #071,-(R0) -- go!
|
|
program_insts = (
|
|
0o012700, # MOV #0176704,R0
|
|
0o176704,
|
|
0o012740, # MOV #177000,-(R0)
|
|
0o177000,
|
|
0o012740, # MOV #071, -(R0)
|
|
0o000071,
|
|
0o0, # HALT
|
|
)
|
|
|
|
for o, w in enumerate(program_insts):
|
|
p.physRW(addr + o + o, w)
|
|
|
|
return addr
|
|
|
|
|
|
if __name__ == "__main__":
|
|
import time
|
|
from machine import PDP1170
|
|
p = PDP1170(loglevel='INFO')
|
|
pc = boot_hp(p)
|
|
print("starting PDP11; telnet/nc to localhost:1170 to connect to console")
|
|
print("There will be no prompt; type 'boot' to start boot program")
|
|
p.run(pc=pc)
|
|
# technically need to confirm the drive is RDY, i.e., the read
|
|
# completed, but using a delay is a lot simpler and works fine.
|
|
# In real life, humans would have manipulated console switches to
|
|
# start execution at location 0, which is also a source of delay. :)
|
|
time.sleep(0.05)
|
|
p.run(pc=0)
|