[Simh] Some beginner questions about RSX11 and/or RSTS on simh...

[Johnny Billquist]

On 2019-12-27 19:53, Dave Shevett wrote:
> On Fri, Dec 27, 2019 at 1:39 PM Paul Koning <paulkoning at comcast.net> wrote:
>> You mean real RSX, not POS?
> 
> So, IIRC, P/OS was built on top of RSX11.  It was the menu system and
> application framework, but under the covers, it was all RSX11.  I
> remember if you had the (development option?) you could drop to a DCL
> prompt and do whatever you liked with it.

Sortof. It's all definitely based on RSX, but P/OS did add some stuff of 
its own, which is separate from RSX.
But for most things, RSX programs will run on P/OS, as long as they 
don't try anything too fancy, and they might not work from the menu 
system, but depends on the DCL environment.
Sortof similar in the other direction as well. P/OS programs will run on 
RSX, as long as you don't try any P/OS specific stuff, or try to call 
the menu system.

Much of the sources are shared between P/OS and RSX, but not all of 
them, and RSX eventually grew to have much more capabilities than P/OS 
ever got.

>>> 1) I'm assuming RSX-11m is where I should be focusing my work - even
>>> though my personal systems were RSTS based, (with an occasional boot
>>> of RT11 to test stuff)  i feel RSX-11m is the more 'complete' and
>>> modern OS (contextually speaking).  Does this make sense?
>>
>> Not necessarily.  It depends a bit on what you want to do.  As Johnny points out, if you want TCP/IP, the only RSX will do thanks to his work.  (Or Unix I suppose, but I assume we're talking DEC operating systems.)  If you want to write device drivers, RSX or RT are options, RSTS is not.  (At least not in the sense of something you can do from documentation -- it *can* be done and has been but unless you were part of the RSTS/E engineering team it's quite tough to pull off.)  If you want something really fast and skinny, RT-11 is the obvious answer.  RSTS/E of course is the place for traditional timesharing.
>>
>> If you are looking for places to run application programs you might have lying around, RSTS/E is probably a very good answer.  It has both RT11 and RSX emulation that's quite solid.  Some real time features may not be great, though they should be faked adequately.  For example, RSTS doesn't have ASTs or asynchronous I/O (except some disk and tape I/O in V9.0 and later) but the emulation will fake it.  Similarly, you can run user interfaces that feel like RT11 or RSX, at least superficially.  And DCL in V9 or V10 is very good.
> 
> It really does come down to "what do I want to do with this" doesn't
> it?  I'm not a strong programmer outside of high level languages
> (though I know a half dozen assembler variants)

Definitely boils down to what you want to do... Pretty much the same 
high level languages exists on both systems.

> I was in college when I started most of my DEC experience, and that
> was all on 11/730's.  Vaxen running VMS.  I wrote a ton of stuff in
> BASIC-11 that used ReGIS to display stuff via the GIGI terminals.
> When I worked for a DEC reseller later, the Pro/350's we had ran a
> bunch of ReGIS demos that were awesome.  I think my ultimate goal is
> to have a GIGI (or, I suppose, anything htat supported ReGIS, which
> includes a VT240 I believe) connected to the PiDP11 running graphics
> stuff.   RSTS/E or RSX11 will do either of these things just fine I
> think.

Yes. Either will cut it.

> I guess mostly I want DCL, EDT, ability to telnet in, and ultimately a
> ReGIS terminal.

DCL and EDT you'll have on either. Not identical, but pretty similar.
telnet is either through the simulator for RSTS/E, or simulator or 
native with RSX.
Anything beyond, like ftp, is RSX only.
ReGIS terminals obviously does not care which OS you are running.

> Oh, and if we're talking ponies, if I could play Empire... one last
> time... :) :) :)

I have the binary. I also have sources, but not for the same version I 
have the binary for... :-)
Runs under RSX, but I would suspect it would run under RSTS/E in the RSX 
RTS as well.

> Right now I'm focusing on finishing up the PiDP11 front panel -
> hopefully that'll be in the next week, then i'll have my blinkenlights
> :)

Always a good start. :-)

   Johnny

-- 
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