Remember that the max physical memory on Qbus is 4mb... Depends on which monitor you are running... the SJ(SB) and FB monitors only use 28kw (56kb)... that is all there is for the OS and user programs. Any additional memory *can* be used as a fast disk volume. Programs should not touch the memory mapping registers, though they can (RT allows one to shoot one's self in the foot) The XM monitor takes over the memory management of the machine and provides system services to allow programs access to all the rest of memory -- but programs have to be written specially to make use of it, otherwise they exist in a 32kw virtual address space. Not integral... there was DECnet/RT, but that was only Phase III, and no Ethernet. It was because of this that I wrote a piece of networking software for RT machines specifically (check my web page). There is a package from DECUS which provides a TCP/IP stack... You can find it through www.trailing-edge.com (or is it metalab.unc.edu that has it). Anyway, I think it is decus package 110939 (but I might be wrong). Try HELP... it will give you the commands available. Unlike MS/DOS and Windows, which don't come with any program development tools, RT is an execution environment *and* a development environment... the tools you need to write your own programs come with the distribution -- an assembler (MACRO), a linker (LINK), a module librarian (LIBR) and several debuggers (ODT, VDT, DBG). Megan Gentry Former RT-11 Developer +--------------------------------+-------------------------------------+ | Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com | | Unix Support Engineering Group | (home): mbg!world.std.com | | Compaq Computer Corporation | addresses need '@' in place of '!' | | 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ | | Nashua, NH 03062 | "pdp-11 programmer - some assembler | | (603) 884 1055 | required." - mbg | +--------------------------------+-------------------------------------+