[HECnet] Silly RSX questions....

Bob Armstrong bob at jfcl.com
Sun Jul 8 17:54:11 PDT 2012


Yes, 4MB is plenty of memory. But normal memory is often not the big issue
in RSX,

  Yep, that's what killed the PDP-11.   Huge physical address space; tiny
virtual address space.   We used to have to go thru all kinds of contortions
(overlays and crap) to fit programs on the -11, even when there were loads
of physical RAM available.

  Thanks for the tip on pool, though.

  Just out of curiosity, does RSX use supervisor mode on the processors that
have it (typically that goes together with I&D space).   2bsd uses super mode
just to get extra address space for the networking code.

Also, don't forget to have the options included to allow for networking in
the kernel. :-)

  Umm, Sure....   I trust that those will be obvious when I see them :-)

your requirements on "user friendly" are pretty high.

  Well, you can boot the same VMS distro on any VAX ever made and it pretty
much just figures it out :-)   Just kidding, though - I'm not looking to
start an argument about which OS is better.

DECnet on 11M also means that you need to understand partitions,

  Partitions?   You mean memory partitions?   On a processor with an MMU??   I
thought that was pretty much all dynamic on M and M+, and only unmapped
systems (like 11S) had to worry about that.   Ok, you recently pointed out
that M can run on unmapped systems too, but the 11/23+ has a perfectly nice
22bit MMU and that's not an issue here.

You know that an RQDX and RD32 are bog slow? 

  Yes, but there are not a lot of other options on the 11/23+.   There's an
RL02 drive, but it's not clear that's actually faster; it's also lots
smaller (in Mb, that is, not in cubic feet!) and probably not as reliable
(although that last one is arguable).   Besides, I'd rather keep the RL02 as
removable media anyway.

Bob



More information about the Hecnet-list mailing list