From: <Paul_Koning at Dell.com>
On Dec 17, 2012, at 6:01 PM, Johnny Billquist wrote:
To make it clear - the PDP-11 have a very normal MMU with pages.
Semi-normal. It's rather unusual in that it has a paged MMU with page
address granularity different from the page size (64 bytes vs. 8k bytes).
Yes that's true, and can be annoying (fragmentation), but at least it's
optional -- if you want to you can do everything on 8 KB boundaries and
then it's just like any later MMU, except that you'll run out of core in
no time.
John Wilson
D Bit
Paul. given the time (late 1960's/early 70's) the prevailing page sizes were 64 / 128 / 256 / 512 bytes which just happen to map to the sizes of blocks used in disk controllers. 1/4/8 k pages were a few years in the future.
by the virtual address extension to the 11 ( aka 1975 's vax 11/780) DEC switched to 512 bytes.
That said as wnj would point out in the "fast vax" paper by 1979 512 bytes was to small.
Clem
On Dec 18, 2012, at 9:45 AM, <Paul_Koning at Dell.com> wrote:
On Dec 17, 2012, at 6:01 PM, Johnny Billquist wrote:
On 2012-12-17 23:50, Boyanich, Alastair wrote:
...
2) Was 2.11BSD ever ported to other platforms? Given the age/era, I'm
curious about 8088/8086/NECv20/80286 given the banked memory models used
and looking at the 8088/8086 XENIX disassembly.
Nope. That would not have been 2BSD then. And since the PDP-11 don't even have banked memory, it would probably cause some headaches to port 2BSD to something like 80286 or other similar machines.
To make it clear - the PDP-11 have a very normal MMU with pages.
Semi-normal. It's rather unusual in that it has a paged MMU with page address granularity different from the page size (64 bytes vs. 8k bytes). Most architectures have those two match, that avoids an adder -- consider VAX or MIPS or Alpha.
paul
On Dec 17, 2012, at 6:01 PM, Johnny Billquist wrote:
On 2012-12-17 23:50, Boyanich, Alastair wrote:
...
2) Was 2.11BSD ever ported to other platforms? Given the age/era, I'm
curious about 8088/8086/NECv20/80286 given the banked memory models used
and looking at the 8088/8086 XENIX disassembly.
Nope. That would not have been 2BSD then. And since the PDP-11 don't even have banked memory, it would probably cause some headaches to port 2BSD to something like 80286 or other similar machines.
To make it clear - the PDP-11 have a very normal MMU with pages.
Semi-normal. It's rather unusual in that it has a paged MMU with page address granularity different from the page size (64 bytes vs. 8k bytes). Most architectures have those two match, that avoids an adder -- consider VAX or MIPS or Alpha.
paul
On 18/12/12 12:57, Brian Schenkenberger, VAXman- wrote:
WRT DECtek, aren't you re-inventing the wheel? There already exists such a list (Info-VAX) and it's gatewayed to the usenet comp.os.vms groupt. I think that if it's more overarching info you're looking for that you might want to look there -- at least, for VMS related topics. There are several DECcentric usenet groups which cover DEC hardware and PDP focus as well -- I'm not aware of mailing list gateways in the latter case.
I find DECtec a more 'intimate' place to discuss DEC related stuff, however yes, there is a number of alternative outlets. Generally I would have thought the best alternative would be comp.sys.dec for most of the discussions we have here.
Regards, Mark.
Brian Hechinger <wonko at 4amlunch.net> writes:
On Dec 18, 2012, at 2:34, Mark Benson <md.benson at gmail.com> wrote:
I have already tried to promote an alternative forum for the more
wide ranging topics by starting the DECtec mailing list which is a
wider overarching enthusiast list for DEC/Compaq/HP users. In spite of
many people from this list also being also subscribed to DECtec it
doesn't seem to have worked all that well. The list is mostly silent.
WRT DECtek, aren't you re-inventing the wheel? There already exists such
a list (Info-VAX) and it's gatewayed to the usenet comp.os.vms groupt. I
think that if it's more overarching info you're looking for that you might
want to look there -- at least, for VMS related topics. There are several
DECcentric usenet groups which cover DEC hardware and PDP focus as well --
I'm not aware of mailing list gateways in the latter case.
I think the problem is that people don't intentionally post off topic
here. It always seems to start out as HECnet/DECnet related and then
and some point wanders off the trail following a squirrel.
It's the nature of the beast. It starts out in a clearing and then goes
to wander off into the weeds.
--
VAXman- A Bored Certified VMS Kernel Mode Hacker VAXman(at)TMESIS(dot)ORG
Well I speak to machines with the voice of humanity.
Although sometimes the case, That's not what I've observed 100% of the time. New off-topic threads often start discretely off the back of stuff people are discussing in on-topic threads.
The problem is HECnet is not *just* a network with a network admin and a customer service mailing list. We are an enthusiastic and vibrant community, which is good, but it can lead to a bit of meandering!
--
Mark Benson
http://markbenson.org/bloghttp://twitter.com/MDBenson
On 18 Dec 2012, at 12:48, Brian Hechinger <wonko at 4amlunch.net> wrote:
On Dec 18, 2012, at 2:34, Mark Benson <md.benson at gmail.com> wrote:
I have already tried to promote an alternative forum for the more wide ranging topics by starting the DECtec mailing list which is a wider overarching enthusiast list for DEC/Compaq/HP users. In spite of many people from this list also being also subscribed to DECtec it doesn't seem to have worked all that well. The list is mostly silent.
I think the problem is that people don't intentionally post off topic here. It always seems to start out as HECnet/DECnet related and then and some point wanders off the trail following a squirrel.
-brian
Much better!!
-brian
On Dec 18, 2012, at 7:18, "Brian Schenkenberger, VAXman-" <system at TMESIS.COM> wrote:
Greetings HECnetters...
This is just a quick post to determine if my email addy is now properly
registered to allow me to post to the list. I hope this doesn't create
a huge barrage of OT replies. ;)
--
VAXman- A Bored Certified VMS Kernel Mode Hacker VAXman(at)TMESIS(dot)ORG
Well I speak to machines with the voice of humanity.
On Dec 18, 2012, at 2:34, Mark Benson <md.benson at gmail.com> wrote:
I have already tried to promote an alternative forum for the more wide ranging topics by starting the DECtec mailing list which is a wider overarching enthusiast list for DEC/Compaq/HP users. In spite of many people from this list also being also subscribed to DECtec it doesn't seem to have worked all that well. The list is mostly silent.
I think the problem is that people don't intentionally post off topic here. It always seems to start out as HECnet/DECnet related and then and some point wanders off the trail following a squirrel.
-brian
Greetings HECnetters...
This is just a quick post to determine if my email addy is now properly
registered to allow me to post to the list. I hope this doesn't create
a huge barrage of OT replies. ;)
--
VAXman- A Bored Certified VMS Kernel Mode Hacker VAXman(at)TMESIS(dot)ORG
Well I speak to machines with the voice of humanity.
Mark, the DECtec list proves, I feel, that HECnet members are interested in DEC hardware and software. And these interests are even broader than what DEC manufactured.
So various topics get into the mix.
The same seems to happen to comp.os.vms where comp.sys.dec kind of posts appear if only because the latter newsgroup is less active and mostly because you know the real experts read cov too. The same applies here. If I'd have a particular RT11 or RSX11M+ question then I"d drop it here ...
Hans
-----Original Message-----
From: Mark Benson <md.benson at gmail.com>
Sender: owner-hecnet at Update.UU.SE
Date: Tue, 18 Dec 2012 07:34:19
To: <hecnet at Update.UU.SE>
Reply-To: hecnet at Update.UU.SE
Subject: Re: [HECnet] digest mode
On 18 Dec 2012, at 00:22, Johnny Billquist wrote:
Ouch, Peter. Sorry that I'm contributing to the spam. I do agree that the flurry of mails these last two days have exceeded anything I would normally expect, and it is getting a little much off-topic.
Let's see if it calms down some, or else I'll put on my hat and ask for some of it to move elsewhere.
The mailing list *is* intended for HECnet specific things, and of course there pops up tangental questions, but Hercules and other things are a little too far out, if you ask me.
I have already tried to promote an alternative forum for the more wide ranging topics by starting the DECtec mailing list which is a wider overarching enthusiast list for DEC/Compaq/HP users. In spite of many people from this list also being also subscribed to DECtec it doesn't seem to have worked all that well. The list is mostly silent.
The whole idea was prompted by a past period when the list got jammed with non-on-topic posts, a lot of which were interesting and valuable, but didn't concern HECnet.
--
Mark Benson
http://DECtec.info
Twitter: @DECtecInfo
HECnet: STAR69::MARK
Online Resource & Mailing List for DEC Enthusiasts.
