Path: utzoo!utgpu!watmath!att!tsdiag!ocpt!pechter From: pechter@ocpt.ccur.com (Bill Pechter ) Newsgroups: comp.unix.wizards Subject: Re: 4BSD file system structure Summary: VMS boot Prom and BSD Message-ID: <20@ocpt.ccur.com> Date: 17 Nov 89 00:36:35 GMT References: <3410@netcom.UUCP> <20643@mimsy.umd.edu> <1602@minyos.xx.rmit.oz> Organization: CONCURRENT COMPUTER CORP. OCEANPORT NJ Lines: 51 In article <1602@minyos.xx.rmit.oz>, rcodi@chudich.co.rmit.oz (Ian Donaldson) writes: > chris@mimsy.umd.edu (Chris Torek) writes: > >In article <3410@netcom.UUCP> hinton@netcom.UUCP (Greg Hinton) writes: > >>If so, doesn't the presence of the boot block throw things off? > > My guess that the 4.[23]BSD way of putting the boot block into the first > part of the filesystem stems from the fact that: > > 1) at the time that the FFS was introduced, there was no > 4BSD disk labels (except from some vendors such as Sun), > and the VAX prom may have booted VMS this way (I'm not > sure about this). > The 4.3-tahoe release added the labels. > > Care to comment Chris? > > Ian D I guess I ought to jump in here -- there was a boot prom on Vax 11/750's that read in the boot block from cyl 0, sector 0, track 0 -- but that was the only Vax that did that. The rest used the console floppy or TU58 DECtape to read in a console program or loader that did the initialization. It was a pretty limited (i.e. AWFUL) way to do things. DEC had to go to the console tape mode on the 11/750 when they went to Vaxclusters... However most 11/750 owners on Unix used the bootprom to boot... There were up to 4 proms available -- labeled A through D. There was usually an RH780, RK07, TU78 and RA81 rom on the later Vax 750's. The minimum was either RH or RK07 with TU58. We did the rom boot when I was at Eaton on SysV Rel 2 and I know others using 4.2bsd did the same. The TU58 took up to 3-5 minutes to load. DEC clusters running VMS also had to download microcode to the CI750. Also, I seem to remember some SysV Unix sites had to put in a Translation Buffer patch sometimes from the TU58 on boot. The 11/730 was worse -- it had 2 TU58's -- 1 with microcode, one with console and boot. Excuse faulty memory -- it's been about 2 years since my last 11/750 -- and about 3 since my DEC Field Service Days... -- Bill Pechter -- Home - 103 Governors Road, Lakewood, NJ 08701 (201)370-0709 Work -- Concurrent Computer Corp., 2 Crescent Pl, MS 172, Oceanport,NJ 07757 Phone -- (201)870-4780 Usenet . . . rutgers!pedsga!tsdiag!scr1!pechter ** MS-DOS is CP/M on steroids, bigger, bulkier and not much better **