On Tue, 21 Jun 2005 Paul Koning <pkoning at equallogic.com> wrote:
 
>>>> "Tony" == Tony Duell <ard at p850ug1.demon.co.uk> writes:
  Tony> I suppose you could include the Pro 325 and 350 (no I/D, F11
  Tony> chip) and the Pro 380 (split I/D, J11 chip). But those will not
  Tony> run normal PDP11 software, the I/O is totally different I
  Tony> believe.
 It certainly is -- different and very badly conceived.  But then
 again, Unibus and Q-bus are also different (though not by the same
 magnitude).  A number of OSs run on PROs -- RT, Unix, P/OS, perhaps
 stock RSX as well.  And the RSTS standalone initialization module will
 boot on a PRO in V9.6, though OS support for it was never released... 
 
No, stock RSX will not run. But P/OS is more or less built from the same
sources. There are some conditional stuff in the RSX sources for P/OS, and
then you need device drivers...
So yes, the PRO is different. Same CPU architecture, different I/O
architecture. The Q-bus is actually similar enough to Unibus that many
devices look same enough to share code between the buses.
A few things differ, but few enough that you can conditionalize them, or
even in some cases, let the OS hide that difference.
        Johnny
Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: bqt at update.uu.se           ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol