Prior to developing DECnet phase II products, DEC had an internal project to develop a bare-metal executive on PDP-11’s, targeted at communications services, for testing the base DECnet protocols; NSP, DDCMP and about 8-10 device drivers. Rather than implement this all from scratch, the phase II developers for DECnet-11M/S and DECnet-11D/IAS “ported” this executive into their respective systems (it only required 2 entry points from the kernel; a scheduling entry and a timer entry, actually 2 timer ones - a slow and a fast timer). By looking at the low memory locations relating to DECnet in the RT-11 source tree, I guessed that DECnet-RT shared the same pedigree as DECnet-RSX and these latest images confirm that. The files on Jay’s disk images confirm that it is a phase III implementation targeted for an 11/23. The node address is 124 so that implies that it was part of a second release of phase III (the first phase III release only supported 32 network nodes, while the later one supported up to 256 nodes). It looks as though most of the components are on the images but it’s not obvious to me how they get loaded into memory. RSX has a “:NCP SET SYS” command to load everything into memory using a program called NTL. NTL is on the RT disks but NCP won’t run if the network device is not loaded. John.