Al> I suspect that the driving force for tools (esp in TOPS-10) Al> inside DEC came about because much of the software development Al> inside of DEC for other CPU families until they converted to Al> VAXen was done using cross-development tools on their internal Al> timesharing systems (MACY11, etc.) ... Don't know about the others, though I have my guesses about RSX -- but in the case of RSTS at least, software development was "native" not later than 1975 or so (RSTS/E V5B). == The time frame I was really thinking about was '65 -> early 70's And RT11 development probably was hosted on RSTS at some point. (So was OS-8 support, on an 11/60, since it could run PDP-8 code very fast thanks to the WCS option.) == I'm sure Megan knows all the gory details of that. This is also the first I had heard that Richie's PDP8 microcode was actually used for product development.