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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal> 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. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal> If you’d like to know more, you can read a detailed account of the whole adventure here –<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal style='text-indent:.5in'><a href="http://walden-family.com/bbn/imp-code.pdf">http://walden-family.com/bbn/imp-code.pdf</a><o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal> Everyone involved has agreed to release their work under the same terms as Bob Supnik’s original simh license, and I’m looking for suggestions as to how to handle that. We could just ZIP everything up and host it on the website along with all the other BBN and ARPAnet documentation. If the community considers the simh extensions for the BBN hardware to be of general interest then it could be submitted to the current simh repository. Or it could go somewhere else - I am open to suggestions.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks,<o:p></o:p></p><p class=MsoNormal>Bob Armstrong<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>