From mboxrd@z Thu Jan 1 00:00:00 1970 From: lbickley@bickleywest.com (Lyle Bickley) Date: Thu, 25 Jun 2009 15:17:10 -0700 Subject: [TUHS] Can't load split I&D files (in one PDP-11/23 PLUS) In-Reply-To: <4A43EB6E.1030807@dunnington.plus.com> References: <20090625204930.GC10610@freebie.xs4all.nl> <4A43EB6E.1030807@dunnington.plus.com> Message-ID: <200906251517.10301.lbickley@bickleywest.com> On Thursday 25 June 2009, Pete Turnbull wrote: > On 25/06/2009 21:49, Wilko Bulte wrote: > > Quoting SPC, who wrote on Thu, Jun 25, 2009 at 08:57:47PM +0200 .. > >> Well, the matter is simple: I'm trying to install 2.11 BSD in one PDP-11/23 > >> PLUS with 4MB of ram, and the 'restor' and 'icheck' utilities don't load in > >> he PDP, returning this message: > >> > >> "Can't load split I&D files" > >> > >> I tried with the diverse distributions of Vtserver and diverse versions of > >> 'restor'. In the case of the 2.9BSD this don't happen but the utility can't > >> understand what is the 'vt' device. > >> > >> Someone has encountered and solved this problem ? > > > > I could be wrong, but I think the 11/23 is not a split ID CPU? > > Correct, it isn't. You cannot run 2.11BSD in a PDP-11/23 or similar > machine because a lot of things in 2.11BSD require split I&D. It's > declared on the first page of the setup instructions: > > "This distribution can be booted on a PDP-11 with 1Mb of memory or > more, separate I&D, and with any of the following disks:" > > You need an 11/73 or better to have split I&D. For those who might not > know what that means, it refers to the processor's ability to keep > I(nstructions) and D(ata) in separate spaces, so in effect virtually > doubling the amount of memory that can be used. That is, you can have > (almost) 64K of instructions *and* (almost) 64K of data at the same > time. Without split I&D, you have 64K in total for both. As Pete says, you can't run 2.11 on an 11/23. However, I do run 2.9 BSD on my 11/34 as it does NOT require seperate I&D as does 2.11 BSD. Might want to try using 2.9 on your 11/23. Here's the CPUs supported by 2.9 BSD: 11/23, 11/24, 11/34, 11/34A, 11/34C, 11/40, 11/44, 11/45, 11/55, 11/70 Min. required memory is 192K Regards, Lyle -- Lyle Bickley Bickley Consulting West Inc. http://bickleywest.com "Black holes are where God is dividing by zero"