MicroRSX (was: Re: Archiving RX50s with PUTR)

[Johnny Billquist]

"js at cimmeri.com" <js at cimmeri.com> wrote:

> Going a bit OT from archiving RX50's...  I wonder how MicroRSX differed 
> from full RSX11-M, which itself was quite compact?

Don't be fooled by the "Micro" in MicroRSX. It is a referral to that the 
OS was custom adapted for the MicroPDP-11. MicroRSX is actually rather 
big. It's a customized version of RSX-11M-PLUS for a specific set of 
hardware. As such, it is delivered pre-compiled, and you cannot run 
SYSGEN. Instead, it has a configuration program that runs on boot, which 
can adapt it to the specific needs you have. But the possibility of 
adaptations are limited. You don't get any sources, and if I remember 
right, you don't even get MACRO-11 or TKB with it. Those were options 
you'd have to pay extra for.

It's more of a turnkey system for a specific task. You bought a 
MicroPDP-11, MicroRSX, some application that you wanted to use, and just 
used it.

> It's truly amazing what was once done (in this case, by David Cutler) 
> with so little memory.  Back in 1999, Lars Poulsen wrote:
> 
> "RSX-11D soon grew too large to fit on a 32KB (16KW) machine.
> David Cutler decided that it was possible to implement the same
> services with much less code, starting from scratch, and went on
> to do just that. In 18 months, he basically wrote and debugged
> the RSX-11M kernel. The system was released in source form, and
> with conditional assembly could be configured at compile time
> for any hardware from 8KW 11/05 to a full-house 11/45.
> Over the years I worked on RSX-11M based system integration,
> I eventually got to take a look at most of the modules of 11M,
> and Dave Cutler's name was in the header of each one! "

Yeah, RSX-11M is really nice, small and beautiful. And yes, Cutlers name 
is all over the sources.
RSX-11M-PLUS, which is a superset of -11M also share the same code base.

	Johnny

> 
> Then, to hear Mr. Cutler talking as he does here, was quite a surprise:
> 
> http://www.amd.com/us-en/Weblets/0,,7832_8366_7823_8718%5E7839,00.html
> 
> jS
> 
> 
> 
> 
> Tobias Russell wrote:
>> > I've put up the microRSX-11 distribution floppies for anyone who is
>> > interested. They can be found here:
>> >
>> > http://www.pdp11.co.uk/2009/05/17/microrsx-11-rx50-distribution/
>> >
>> > I've started to play with getting this up and running on simh. It seems
>> > to boot the install floppy ok, although it hung after I selected install
>> > from the menus. If anyone has better success, please let me know as I
>> > would like to get this up and running.
>> >
>> > All the best,
>> > Toby



-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol