We spent the last four days investigating how we can bring our PiDP-1 on Arpanet. Yes, really. Because (1) there is some major history there, and (2) there's a major new project from Lars Brinkhoff where this would be significant Icing On The Cake.

The history: so Arpanet consisted of IMP routers. Not very well-known is that the software for the IMPs was developed with the help of a PDP-1, at BBN by a small team called The IMP Guys. Actually, in the first-ever instance of remote software updates, the PDP-1 sent over-the-net software updates to all the IMP routers in the field. The PDP-1 also acted as the watchdog for Arpanet stability, constantly chatting to the IMPS in the field.

And as it happened, we were brought in touch with one of the actual IMP Guys at BBN - who did the coding. We found large parts of the PDP-1D time-sharing system (alas, in PDF format) and lots of technical memos from the IMP Guys. So - we now have to think about how impossible it would be, exactly, to get that all going again on the PiDP-1.

     Arpanet in 1973, with BBN and its PDP-1 in the top-right section

The major new project: Lars has brought up the simulator of the IMP hardware, running the original software, got the Arpanet code running on PDP-10s with ITS (so we 'have MIT up on Arpanet) and with WAITs (so we 'have Stanford up on Arpanet'). As well as PDP-11s running unix v6. Although, that's not quite up yet. Amazingly, he also wrote a Network Control Program for Linux - so any Linux box now connects to real or simulated IMPs and go out on Arpanet.

So - imagine, if we can get the PDP-1 at BBN online too, we'd have a pretty full reconstruction of Arpanet circa 1973. But reality now sets in - will we really be able to get the PDP-1's Network Control Program back? Large chunks outside the OS are missing and will have to be rewritten. 

   The PDP-1 at BBN, just before the Era of Arpanet

--> this is a call for help! If you have any old code, documents or papertapes relating to the PDP-1 at BBN, Stanford or USC, please, please let us know.