But IIRC there was an earlier flag date when all the TOPS-20 and TENEX systems switched to TCP/IP (somewhere in 1979-80?), and that was the real breath-holder f

But IIRC there was an earlier flag date when all the TOPS-20 and TENEX systems switched to TCP/IP (somewhere in 1979-80?), and that was the real breath-holder for those of us dependent on (and responsible for) those systems at the time. The first TCP/IP implementation for TENEX/TOPS-20 was kind of a dog (large and complex and slow, of course written in -10 assembler), but over time it got tuned quite a bit. When I was at Imagen, a Stanford TeX project laser printer spin-off using the same SUN-1 boards as the first Sun workstations and Cisco routers, we hired Geoff Steckel. Geoff was a genius from the Dave Clark (co-inventor of TCP/IP) group at MIT. He wrote for Imagen a very small, tight, super-fast TCP/IP implementation in C, since he had quite a bit of practice at it in Dave's group.