V2057A%TEMPLEVM.BITNET@cornellc.cit.cornell.edu (Juan Jose Noyles) (05/31/90)
I'm sad that you don't believe me, Mikey, but I worked with it for three semesters. My 11/34 was a 64K machine. I had 3 RP03s (the washing machines), an RP05 or two (the 5Mb removables, I think) and some other critter. I don't remember it because I didn't think I'd need to. Sorry you weren't there, dude, but that's the way it was.
Pat_Barron@transarc.com (05/31/90)
"Vanilla" V7, straight from Murray Hill, did *not* run on the 11/34, since the kernel was big enough that it required separate I&D space. DEC had a version they called "V7m", which had kernel overlays and could run on non-separate I&D space machines like the 11/34. And it had fsck, too. But other than that, it wasn't much different from regular V7. Perhaps that's what you had? --Pat.
lennox@lectroid.sw.stratus.com (Craig Scott Lennox) (06/01/90)
Excuse my ignorance, but what does "I&D space" mean? -- | flame me at: lennox@shire.hw.stratus.com, Craig Lennox, Stratus Computer | |"Oh boy, virtual memory! Now I'm gonna make myself a REALLY BIG ram disk!" | | Disclaimer: My opinions are covered by section 2b of the Gnu Public | | License and thus do not belong to Stratus Computer. |
bill gunshannon <702WFG%SCRVMSYS.BITNET@cornellc.cit.cornell.edu> (06/01/90)
I&D = Instruction & Data
The machine used 2 separate 64K blocks of memory one for data and one
for executable junk. Sounds kinda like INTEL small model when you get
right down to it.
It was because although Memory Management allowed up to 512K, the processor
could still only work with 64K at a time. There were worse. I have an
LSI 11/03. It has 56K bytes of word addressable memory or the equivalent
of 28K worth of address space. Try cramming MINIX into that. :-)
bill
bill gunshannon
702WFG@SCRVMSYS.BITNETV2057A%TEMPLEVM.BITNET@cornellc.cit.cornell.edu (Juan Jose Noyles) (06/01/90)
Thank you Pat, for your verification.
norsk@sequent.UUCP (Doug Thompson) (06/01/90)
In article <20721@nigel.udel.EDU> 702WFG%SCRVMSYS.BITNET@cornellc.cit.cornell.edu (bill gunshannon) writes: >I&D = Instruction & Data >The machine used 2 separate 64K blocks of memory one for data and one >for executable junk. Sounds kinda like INTEL small model when you get >right down to it. >It was because although Memory Management allowed up to 512K, the processor >could still only work with 64K at a time. There were worse. I have an >LSI 11/03. It has 56K bytes of word addressable memory or the equivalent >of 28K worth of address space. Try cramming MINIX into that. :-) > >bill > > bill gunshannon > 702WFG@SCRVMSYS.BITNET In 1980, at BYU, we had an old PDP-11/40 (No MMU). We were able to get a copy of Mini-UNIX (v6) that supported 3 users. Like the 11/03, there was only 28kwords of with core, the remaining 4kw was IO space. The kernel was 12k words, allowing only 16k words for program space. Time sharing was like: swap user 1 in, run for a second, swap user 1 out, swap user 2 in, run a second, swap user 2 out, swap user 3 in, run a sec, and repeat. ... The system compiled itself, and worked fairly good. I even did my compiler course on it - the only one in the class who used a high level language - all else used DEC asm. ugh! Things were small then, but we got alot done. -- Douglas Thompson UUCP: ..{tektronix,ogicse,uunet}!sequent!norsk "The scientist builds to learn; the engineer learns in order to build." Fred Brooks
root@relay.eu.net (06/04/90)
>From article <20666@nigel.udel.EDU>, by Pat_Barron@transarc.com: > "Vanilla" V7, straight from Murray Hill, did *not* run on the 11/34, since > the kernel was big enough that it required separate I&D space. DEC had > a version they called "V7m", which had kernel overlays and could run on > non-separate I&D space machines like the 11/34. And it had fsck, too. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Big mistake here: the '34 WAS A FULL UNIBUS MACHINE WITH 18-BIT ADDRESS LINES AND SEPARATE I AND D SPACE !!!!!!! Thus, the 11/34 has (yes, present time. I still have some!) an addressing capability of 256Kb (minus 8Kb UNIBUS space at the top). One process could be split into two segments each: I and D. This allowed for much larger processes to be run. Remember, guys, that all major PDP-11's (so, not counting the '05, '10 (== 05), 20, ...) have a builtin MMU. Therefore, this discussion is pointless. The PDP-11 is a 256Kb-machine, *NOT* a 64Kb-machine! The 11/70 and all 22-bit Qbus machines have an addressing space of 4Mbyte. Again, with or without SepID. > What is I&D ? I&D means "separate Instruction and Data space". The chunks of code and data of a program can be put into a single segment of memory, or they can be put into separate segments, which then allows for larger processes! > But other than that, it wasn't much different from regular V7. Perhaps > that's what you had? _I_ had a vanilla 11/34 with 128Kw of memory running BSD2.9. The other machine ran V7 at first, but we put BSD2.9 on that too, since it was much faster. Now, can we stop this part of the discussion, or move it to another group? I think we are boring lots of other people.... Fred van Kempen MINIX User Group Holland
Pat_Barron@transarc.com (06/05/90)
Fred van Kempen writes: >>From article <20666@nigel.udel.EDU>, by Pat_Barron@transarc.com: >> "Vanilla" V7, straight from Murray Hill, did *not* run on the 11/34, since >> the kernel was big enough that it required separate I&D space. DEC had >> a version they called "V7m", which had kernel overlays and could run on >> non-separate I&D space machines like the 11/34. And it had fsck, too. > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >Big mistake here: the '34 WAS A FULL UNIBUS MACHINE WITH 18-BIT >ADDRESS LINES AND SEPARATE I AND D SPACE !!!!!!! Sorry, this is not correct. The 11/34 had (has) an 18 bit Unibus address space, but no separate I&D. The separate I&D machines are (from memory; hopefully I won't leave out any): the 11/44, 11/45, 11/53, 11/55, 11/70, 11/73, 11/83, 11/84, 11/93, and 11/94 (yes, there are such things as the 11/93 and 11/94 - Digital just recently announced these two new PDP-11's!). >Thus, the 11/34 has (yes, present time. I still have some!) an addressing >capability of 256Kb (minus 8Kb UNIBUS space at the top). One process could >be split into two segments each: I and D. This allowed for much larger >processes to be run. If you have separate I&D, you don't have an 11/34. >Remember, guys, that all major PDP-11's (so, not counting the '05, '10 >(== 05), 20, ...) have a builtin MMU. Therefore, this discussion is >pointless. The PDP-11 is a 256Kb-machine, *NOT* a 64Kb-machine! >The 11/70 and all 22-bit Qbus machines have an addressing space of >4Mbyte. Again, with or without SepID. True, but irrelevant. A memory management context on the '11 is only 64Kbytes (64K code + 64K data, if you have separate I&D), so unless you play funny games with overlays (like they had to do with the V7m kernel, and like 2.9BSD has to do to run large programs [like "vi"] on non-separate I&D machines), you're still stuck with the 64K limit, no matter how much physical memory your machine has. Also, it's not necessarily true that all the "major" PDP-11's have built-in MMUs (although, most useful configurations do include one). For instance, my old 11/24's MMU (as well as the one on my 11/23 - which is actually the same CPU and uses the same MMU chip) was an optional feature, as was the "Unibus map" (which allowed the 11/24 to access 22-bits worth of memory). >> But other than that, it wasn't much different from regular V7. Perhaps >> that's what you had? >_I_ had a vanilla 11/34 with 128Kw of memory running BSD2.9. >The other machine ran V7 at first, but we put BSD2.9 on that too, >since it was much faster. V7 didn't run on the 11/34 (really - I have the original V7 documents from Murray Hill that explicitly say this). V7m would run on the 11/34, because it had an overlaid kernel. 2.9BSD had an overlaid kernel, too, like the V7m kernel. As far as I know, no V7-based system that ran on non-separate I&D machines ever came out of Murray Hill. >Now, can we stop this part of the discussion, or move it to another >group? I think we are boring lots of other people.... Agreed. I might suggest that anyone interested in continuing this discussion do so on the INFO-PDP11 mailing list, which I maintain. The mailing list is "info-pdp11@transarc.com"; requests to join and other administrivia to "info-pdp11-request@transarc.com". --Pat.