That's right, I've used RSX and it is definitely the parent of VMS. The MCR command is a leftover from RSX that's still visible today from the user side. The internals, especially $QIO and other low level I/O system services are obviously lifted from RSX.
Back in the VMS 2/3 days when I first used it, you still had to run some RSX programs in PDP-11 emulation mode to do some things. I recall that PIP was the only way to perform certain system functions and it was still an RSX program. All VAX-11 processors could emulate PDP-11s. I believe that all VMS 4 systems still came with RSX emulation if you were running on VAX-11 processors. You later had to buy RSX emulation as a separate package. RSX came about just about the same time as Unix, and I would be surprised if anything from Unix made it into the RSX design or implementation. Unix people like to harken back to it's origins in 1969, but those first few years were really unrecognizably Unix. I believe there was no shell like we know today until much later. I think RSX came about in 1970 or 1971, but that may have initially be RSX-11S. It seems that I recall that Cutler actually didn't get involved until RSX-11M, but I'm fuzzy here. VMS clearly got some ideas from TOPS-10, which lifted some ideas from Multics. Many claim that Unix got some things from Multics, but I'm not sure what that would be (although I'm not an expert in Multics, by any means). So, possibly there's some commonality from that angle. Actually, I think that Cutler was somewhat anti-TOPS-10 and anything that made it in from there was probably underground through the many people who worked on VMS who had once worked on TOPS-10. -Jordan Henderson The common idea that success spoils people by making them vain, egotistic, and self-complacent is erroneous; on the contrary it makes them, for the most part, humble, tolerant, and kind. Failure makes people bitter and cruel. -- W. Somerset Maugham > -----Original Message----- > From: Thomas R Wyant_III [mailto:[EMAIL PROTECTED] > Sent: Thursday, April 03, 2003 9:40 AM > To: [EMAIL PROTECTED] > Subject: Re: vmsperl Digest 2 Apr 2003 21:19:24 -0000 Issue 685 > > > Brad Hughes <brad/[EMAIL PROTECTED]> wrote: > > > Brian Tillman wrote: > > > VMS IS NOT a Unix descendent. > > > Certainly Unix predates VMS. And Multics predated Unix. The > > TOPSes predated VMS, but I'm not sure you could say VMS is > > strictly descended from TOPS. Did Multics and TOPS share a > > common ancestor? > > > Does anyone have an OS genealogy tree... > > I certainly don't know of any "Twurp's Peerage" (sic) for operating > systems. But if VMS is descended from any OS it's RSX. Anyone looking for > good examples of "second system effect" should compare these two. Of > course, this means Windows NT is an example of "third system effect", > since > Dave Cutler was the architect of all three. But NT is really sort of a > bastard nephew to the other two, and gets most of its features from the > "bend sinister" side of the family. > > Tom Wyant > > > > This communication is for use by the intended recipient and contains > information that may be privileged, confidential or copyrighted under > applicable law. If you are not the intended recipient, you are hereby > formally notified that any use, copying or distribution of this e-mail, > in whole or in part, is strictly prohibited. Please notify the sender > by return e-mail and delete this e-mail from your system. Unless > explicitly and conspicuously designated as "E-Contract Intended", > this e-mail does not constitute a contract offer, a contract amendment, > or an acceptance of a contract offer. This e-mail does not constitute > a consent to the use of sender's contact information for direct marketing > purposes or for transfers of data to third parties. > > Francais Deutsch Italiano Espanol Portugues Japanese Chinese Korean > > http://www.DuPont.com/corp/email_disclaimer.html
