65402fbaa1
This summer a group of us worked together to resurrect the original ARPAnet IMP software, and I’m now happy to say that the IMP lives again in simulation. It’s possible to run the original IMP software on a modified version of the H316 simh and to set up a virtual network of simulated IMPs talking to each other. IMP to IMP connections, which would have originally been carried over leased telephone lines, are tunneled over IP. As far as we can tell, everything works pretty much as it did in the early 1970s. IMPs are able to exchange routing information, console to console communications, network statistics, and they would carry host traffic if there were hosts on the network. The hooks are in there to allow simh to support the IMP side of the 1822 host interface, and the next step would be to recover the OS for an ARPAnet era host and then extend the corresponding simulator to talk to the IMP simulation.
65 lines
No EOL
1.7 KiB
Batchfile
65 lines
No EOL
1.7 KiB
Batchfile
;; ***** GENERIC IMP CONFIGURATION *****
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; This simh command file sets up the H316 simulator configuration for a generic
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; IMP node. Note that it doesn't load any IMP code (the caller is expected to
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; do that) and it doesn't define any IMP node specific settings (e.g. modem
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; links, IMP address, etc).
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;
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; RLA [4-Jun-13]
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RESET ALL
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; Define the CPU configuration ...
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; NOTE - real IMPs only had 16K of memory!
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SET CPU 16K NOHSA DMA=0 DMC EXTINT=16
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; Disable all the devices an IMP doesn't have ...
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SET LPT DISABLED
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SET MT DISABLED
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SET CLK DISABLED
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SET FHD DISABLED
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SET DP DISABLED
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; Enable the IMP device but leave the station address undefined ...
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SET IMP ENABLED
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;;SET IMP NUM=1
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; Enable the RTC to count at 50kHz (20us intervals) ...
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SET RTC ENABLED
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SET RTC INTERVAL=20
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SET RTC QUANTUM=32
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; Enable the WDT but don't ever time out (we have enough problems!)...
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SET WDT ENABLED
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SET WDT DELAY=0
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; Enable only modem line 1 and disable all the rest ...
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SET MI1 ENABLED
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SET MI2 DISABLED
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SET MI3 DISABLED
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SET MI4 DISABLED
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SET MI5 DISABLED
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; Enable only one host interface and disable all the rest ...
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SET HI1 ENABLED
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SET HI2 DISABLED
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SET HI3 DISABLED
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SET HI4 DISABLED
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; Just ignore I/Os to disconnected devices ...
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DEPOSIT CPU STOP_DEV 0
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; SS4 ON is required to run DDT!
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DEPOSIT CPU SS4 1
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; Set the TTY speed to realistic values (about 9600BPS in this case) ...
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DEPOSIT TTY KTIME 1000
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DEPOSIT TTY TTIME 1000
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; Don't know for sure what SS2 does, but it appears to have something to do
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; with the IMP startup. Leave it ON for now...
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DEPOSIT CPU SS2 1
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; All done ....
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SET CPU HISTORY=65000
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SET CONSOLE DEBUG=STDERR
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SET WDT DEBUG=LIGHTS |