> ----- Original Message ----- > From: Christian Gauger-Cosgrove <captainkirk...@gmail.com> > To: Bill Cunningham <bill...@suddenlink.net> > Cc: SIMH <Simh@trailing-edge.com> > Sent: Tuesday, March 3, 2015 12:12 PM > Subject: Re: [Simh] Getting rsxs to run on the pdp11 emulator
> Dave Cutler is the "father" of RSX-11/M+, VMS, and Windows NT. Since the topic of "Cutler the Demiurg of VMS" comes up once in a while here and there... In the interests of some historical justice and accuracy, Cutler is "a" father of VMS, not "the" father. The myth that Cutler was "the" father of VMS originated in its public circulations probably from the authors of the "Showstopper" book, who did not have much interest in the subject of VMS, did not have access to the members of early VMS design team and could not know what had been happening there, and also probably (as many if not most book authors) were not against dramatizing and embellishing their story a little. I have not read or heard anywhere that Cutler himself was ever claiming the role in VMS development ascribed to him by this myth. In reality, from the very start there were three key people on the software side in development of VAX and subsequently VMS, and if any "the" father of VMS were to be named at all, it would hands down be Dick Hustvedt. http://en.wikipedia.org/wiki/Dick_Hustvedt Cutler was a technical team manager during the development of initial versions of VMS, however he was not the top #1 architect and technical contributor. "VAX Team A" designing VAX architecture included 3 people from the hardware side and 3 people from the software side. On the software side these were Dick Hustvedt, Peter Lipman and David Cutler. These three also became later the principal authors of VMS kernel. In terms of the magnitude of contribution to VMS among these three a distinct #1 was certainly Hustvedt. A look into VMS source code (authorship and change history in source files headers) in source kits at around VMS late 3.x-4.0 versions timeframe -- about the time when all three departed VMS development -- makes the picture exceedingly clear. Direct code contributions of Cutler to VMS were parts of the kernel, DCL, MCR, autoconfig, 5 drivers and C run-time library. As to the specific parts of VMS kernel, the breakdown of its primary authors is as follows: Cutler was responsible for IO subsystem (except page locking), forking (like in fork processes/fork blocks), exception handling, system timer and timer services, executive pool allocation, bugcheck code, logical names and several miscellaneous facilities (including mailboxes, console IO routines, CHMx dispatcher, adjust stack and error logging interface routines in the kernel). There are no visible Cutler "fingerprints" (change/authorship comments) in any other kernel modules. Hustvedt was the primary author responsible for the scheduler, swapper, synchronization primitives (including event flags and kernel mutexes) and RSE code (that changes process scheduling state in response to system events), AST handling (for all CPU modes), process creation/deletion/starting, process control (suspend/resume/hibernate/wakeup/handling process priorities and names), process shell and null process, system init, SYSGEN parameters, image exit and rundown, power failure handling and recovery, VMB, SYSBOOT, XDELTA and MSCP port driver. In addition, as a secondary author Hustvedt was responsible for 55 other source files in the kernel. Later Hustvedt was also responsible for ASMP (asymmetric multi-processing) and was the driving force behind the advent of VAXcluster. Peter Lipman was the primary author responsible for all virtual and physical memory handling (except swapper). This may sound brief, but these are the most complex and sophisticated modules in the system with extreme importance. One should remember that the ability of VMS to run scores of user sessions in a few megabytes of main memory was a sort of a technical wonder that, one might surmise, greatly contributed to VMS success. In the course of VAX MP project, I had a reason to look through some pieces of these algorithms and implementation code behind them and might say they stay a technical miracle even today, with hardly any modern operating system replicating their complexity and sophistication (of course, in days of RAM plenty this is not much of a pressing issue). In addition, Lipman was responsible as the primary author for image activator, kernel file IO routines and GETDVI. As a secondary contributor he was also responsible for 63 other source files in the kernel. There were also other major VMS components, such as file system, various system processes, later SCA/SCS etc., developed by other people. Thus, though contributions of Cutler to VMS were significant, he by no means was "the demiurge" of VMS as the myth would have it, nor even the architect #1. One may surmise that dedication of I&DS to Hustvedt (rather than Cutler, who by the time the book was published also departed VMS development) was not only a "thank you" by grateful colleagues after the tragedy that happened to Hustvedt and also owing to the "social" role Hustvedt played inside the team (in his social skills Hustvedt is generally remembered to be the opposite of Cutler, as a very friendly person always willing to help, to explain and to teach), but also a reflection of his technical and architectural contribution to VAX/VMS. Hustvedt, who was the key focal point in the VMS team, tragically suffered car accident in 1984 that left him brain-damaged. http://software.intel.com/en-us/blogs/2008/04/23/dick-hustvedt-the-consummate-software-engineer http://seedwatcher.typepad.com/seedwatcher/2008/04/in-memory-of-my.html Here he is pictured (on the left) next to Andy Goldstein, another key VMS developer. http://seedwatcher.typepad.com/.shared/image.html?/photos/uncategorized/2008/04/22/picture_1.png Besides Hustvedt's key contribution to the initial development of VMS, he was also the driving force behind the development of VAXcluster, at a time when Cutler already departed VMS engineering. Lipman departed DEC in 1984 to become a key person in the development of fault-tolerant systems in Tandem, Amdahl and subsequently HP. http://www.linkedin.com/in/peterlipman This is not to diminish Cutler's real contribution to VMS -- it was quite significant, significant enough not to need mythical embellishment by positioning him as "the" father of VMS. _______________________________________________ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
