leichterj@rani.DEC (12/10/84)
Ah, rumors and lack of information! > Newsgroups: net.unix-wizards > Path: decwrl!sun!qubix!ios!oliveb!hplabs!hao!seismo!rochester!cmu-cs-pt!avie > Subject: Re: raw rumour: VAX 8600 & Ultrix > Posted: Mon Dec 3 19:39:11 1984 > > I may not have all my facts totally correct, but here goes anyway. To paraphrase someone - Mark Twain? - it's not so much what you don't know as what you know that isn't so. > Running Unix (or Ultrix) on a 8600 is not as simple as just writing a > simple device driver to talk to the CI. Remember that the CI is this > "intelligent" device that lets a Vax cpu talk to it at a very high > level. It is my understanding that VMS actually gives "filenames" to > the CI to be processed. Unfortunately, there are two problems. The > first is that Unix file names don't look like VMS file names. The > second is that information about the CI is hard to come by. > > ... > Avie (a) The CI isn't a "device" in anything like the sense you seem to have in mind. "CI" stands for "Computer Interconnect". A CI is similar to a Unibus or Massbus. What you meant to say was that the HSC-50 - "HSC" is Hierarchical Disk Controller - talks to a CPU - known to the guys who develop such things as a "compute server" :-) - at a pretty high level. However... (b) The HSC-50 is a DISK server, not a FILE server. It knows nothing about file structures, file names, or directories. (c) Do you claim that "CI" (and HSC-50) documentation is harder to come by than is the usual case for low-level information of this type? > Newsgroups: net.unix-wizards > Path: decwrl!decvax!wivax!cadmus!harvard!seismo!brl-tgr!tgr!God > <root%bostonu.csnet@csnet-relay.arpa> > Subject: Re: Hacking OS sources > Posted: Thu Dec 6 10:29:50 1984 > RE: Buying and hacking VMS sources... > > I started to look into this to as we had some significant > misfeature problems under VMS, like no CBREAK mode > (ie. no XON/XOFF while passing chars reads, we want to > use things like EMACS over our flow controlled tty net.) Even in VMS V3, it's not THAT hard to use binary mode or out-of-band interrupts for this purpose; but in fact VMS V4 has a "PASTHRU" mode which does exactly what you want. Yes, VMS evolves. > It seemed to me that: > > a) Yes, it is expensive but that's all relative. > b) It's more than you think, as it is written > in a few languages and you have to have and > support all those languages just for this one > purpose (eg. BLISS) MACRO, which comes with the system, plus BLISS, will cover just about every- thing. There are probably a couple of exceptions - but that's what you get when you have a system that really and truely supports a common language envi- ronment - pieces get written in the most appropriate language, and they work together. > c) I heard (tell me if I'm wrong) that a sysgen > from source can take many many hours on a 780 > and basically requires all those to be standalone. > (I guess we could call buying a spare 780 just > another expense.) Very true. But why would you want to rebuild the ENTIRE system? Any well- designed system is modular - you re-compile what you've changed, not all the stuff that is constant. This modularity includes the kernel and the device drivers. > ... > Similarly, you COULD put the VMS manuals on-line but they were > never designed to be on-line and would require something much > more sophisticated than the UNIX 'man' command to make it useful. > ... There is a fundamental difference between the VMS philosophy of "documentation as tutorial" and the Unix one of "documentation as reference". It really wouldn't make much sense to keep it all on-line, even if you could afford the disks - something like 150,000 blocks, as I recall. What you have on-line is a help system that in practice provides all the "reference" information you need most of the time - and is generally much easier - and MUCH faster - to use. (To use a Unix analogy, I can get information about the stty -raw switch directly - by typing HELP SET TERMINAL/PASSALL - without having to read three pages of stty stuff. I can get THAT on VMS by typing HELP SET TERM QUALIFIERS.) > -Barry Shein -- Jerry