<The PDP11 (at least every PDP11 that I've used) addresses memory by
<bytes. OK, a 16 bit word, like an instruction, does have to lie on at an
<even address, but the 16 bit address that a program generates (before
<translation by the MMU) addresses one of 64K _bytes_
True but, if the memory contained nothig but instructions and addresses
32KW is the limit. Only data or IO is addressed as bytes. This would
seem a trivial item it makes a difference in terms of the total number of
instructions in any given amount of ram. This is more important when
applied to machines with I&D space where the byte addressability can be
exploited for buffers and the like.
<The I/O page (certainly on Unibus PDP11's) is 4 K _words_ long. Without
<an MMU you have 28kW memory, 4kW I/O
Some versions and OS vaiations allowed a 2KW IO space. I've run RT-11
that way.
<Wit hthe MMU enabled you can have 64k Bytes (32 k Words) of memory mapped
<in. In fact you generally don't map the I/O page into user processes,
<since you don't want user processes accessing device registers.
True but then people ahve to understand that the MMU design seperates user
space from system space.
<Even if you have the MMU it's a lot simpler if your program fits into 32
<kW (or 28kW if you want access to the I/O space). Otherwise you have to
<do something like using a software interrupt to change the MMU to a
<different mode.
I tried to keep it simple.
<Unless page K1-11 of my PDP11/44 printset is wrong, the PDP11/44 has 22 b
<addressing. The PDP11/45 does, indeed, only have 18 bit, alas...
With the exception of the 11/70 I thought most of the unibus machines were
limited to 18bits, for some devices that can be a limit. My interaction
with U-bus machines is limited to the 11/70 and a 11/34 all my PDP11 time
is with Q-bus (11/03, falcon, 11/23, 11/23A, 11/23b, 11/73) which has
sufficient enough variation to track.
Allison
< Allison, this was private email, but I figure this may be
OOPs, though I did check the header as classiccmp...?
< like the 11/23 and 11/73 line should run this BSD variant as
< well... what I want to know is, did the kernel fit into 64K in
< one segment, or did they spread the kernel across segment
< bounderies? If so, how?
The kernel never fit in 64kb as the pdp11 is word addressed also the MMU
operates on 4kb pages. Also the top 4kbytes are IO space. So the idea of
the kernel fitting in 64k is not relevent. The real question was did it
fit in the 11/44 or 45 who only had 256k (18bit addresses) space. The
11/23 and later Qbus machines were Q22 (4mb address space). The larger
space means more available ram that can be used without resorting to
swapping (or at least less frequently).
Also PDP11s come in two other flavors, those with I&D space and those
without. The 11/23 and 11/34 are those without. The 44, 45, 70, 73,
83 and others have I&D which means that Instructions and Data spaces can
be seperate doubling the amount of memory available. Added to that is
user and system space (memory protection between processes). So it's
possible for a PDP11 to actaully address four distinct areas of memory
that are non-overlapping and all 64k in size. Practical considerations
limit it to less than that but it's nearly so and likely they would
overlap as well.
< I mean, I could see overlays (in the kernel... blech!), but I
< don't remember the 11 supporting long long jumps... and address
< value was 16 bits, period. Still, I was never great at 11
True of all segmented address machines. The larger 256k or 4mb space is
broken into pages of which up to 8 are mapped into the 16bit address
space. To do a long jump what is really done is the cpu remapped the
needed page into logical space and does a 16bit jump to that page.
The top 4 bits determine what page register is addressed and the contents
of that register is appended to the lower 12 bit to form the larger
address needed to manage a 4mb space.
It takes 8 MMU registers and uses the content of the reg plus the 16bit
address to form an address in physical space.
< assembly. Could someone here give a good detailed account of
< PDP-11 segment mapping support? Could my stack and register
< values be retained and follow while moving from segment to
< segment? And how the hell did you tell the memory manager you
< wanted to pop to another segment, anyway?
yes! A detailed discussion would wear out my fingers typing it.
Sufficient that it was able to address more than 64k and while different
than the 8088 or 286 in both cases the 16 bit address space was extended
by argumenting the basic addressing and not extending the basic register
set.
I'm currently building a system using the z80 cousin called the z280 that
can address 16mb of ram and the basic addressing is still 64k argumented
by a MMU.
Allison
> I seem to remember early Ethernet interface VAX quad cards
> being around 1.5Mbps... not sure if it was think ether, vampire
> tap stuff... This would have been before ethernet was turned
> into a 'standard.' One guy I know has one of these hanging
That is a DMC-11. It was an early networking card before Ethernet. It
was point to point, 4 wire coax, synchronous serial at something around
1.5Mbps. The DMC-11 had an onboard bit slice processor (might have been
a Signetics 8X305, not sure) to handle the packet assembly/disassembly.
BTW the KMC-11 was a generic DMC-11 that was user programmable, if you
wanted to roll your own protocols. I used a pair of DMC-11s in 1977 to
network two PDP-11/34s with an early version of DECnet. I don't recall
that DEC had any multi-drop type network interface at that time, except
maybe for X.25 PADs.
< Alright, so what we have is the last 4KW used up for stack
< space, register mapping, and IO mapping. I would guess the
and also boot proms. Default boot on PDP11 is 173000Q. The first
page is where all the vectors for the interrupts and traps are.
< MMU... do I have it right? Even on a machine with a full
< 22bits of address lines on the backplane, like an 11/73, the
< CPU still only has a 16bit address space. The faq doesn't make
< it terribly clear what happens if you want to open up any
< arbitrary window.
Think of the 4mb (q22) as linear physical space. At any time the CPU/MMU
can allocate contigious or scattered blocks of that space as logical
physical space. To do a "long jump" a local jump to a system space is
done, memory management code is run and then a jump to the now available
code (in logical space) is done. One of the background jobs would be to
swap out old segments that are unused to make room for current processes
and swap them back if the non current process should wake up.
The cpu is always in logical 16bit space but the windows (multiple)
can be moved around.
An ascii graphic would show the CPU 16bit space as several blocks
mapped to multiple blocks scattered in a larger space. The cpu
literally never leaves the range of a 16bit space but instead trade
out chunks of it for different ones out of an available pool. You never
actually jump put of logical space only shuffle what physical memory is
part of that space.
Allison
who bloody cares?! people, deal with your own problems; I dont want to hear
about them on the list. I have enough to deal with myself!
david, back to deleting stupid messages <again>
In a message dated 98-04-10 17:47:45 EDT, you write:
<< Without comment
enrico
Anonymous wrote:
>
> Are you a fucking idiot, Limey? Cut the damn crying on the mailing list or
you might just open a message one day and have your whole machine become
instantly erased...Not a threat, a promise.
--
========================================================
Enrico Tedeschi, 54 Easthill Drive, Brighton BN41 2FD, UK
Tel/fax(+01273) 701650 (24 hours) and 0498 692465 (mobile)
please visit my website at: <http://www.brighton-uk.com>
========================================================
On Apr 10, 21:13, Zane H. Healy wrote:
> Subject: gcc for VAX VMS
> This touches on yesterdays VS2000 discusion. Somehow I got lucky today and
> found a pointer to a VAX version of gcc at
> ftp://ftp.cco.caltech.edu/pub/rankin/ of course I'm still trying to find a
> VAX VMS version of tar and gzip so I can install it.
Take a look at
http://www.openvms.digital.com/openvms/freeware/cd.html
Near the bottom of the page you'll find the "Tools" section, which includes
zip, unzip, gzip, and vmstar. Unzip, gunzip, and vms tar are also on Digital's
ftp site. There's a pointer at
http://www.digital.com/info/vms-freeware.html
or ftp directly from ftp://ftp.digital.com/pub/VMS/vmstar-vax.exe
Now, can someone remind me of the URL for VMS hobby licensing so I can do
something about my MicroVAX?
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
now, back to something on topic...
picked up an unenhanced //e system for $10. a bit dirty from no use and a
broken shift key, but powers up fine. came with 2 floppies, monchrome display
which needs the contrast control cleaned and the ever popular system saver.
this one has a hayes micromodem //e whereas the ][+ i got last week had a
micromodem II. besides the way they connect to the phone line, are there any
major differences? i presume both are still 300bps.
david
On Apr 11, 14:11, J. Maynard Gelinas wrote:
> Alright, so what we have is the last 4KW used up for stack
> space, register mapping, and IO mapping. I would guess the
> first 4KW were used up by the boot prom and monitor, which
> leaves about 12KW for an application jump table and
> initialization, the rest for memory mapped windows to the
> MMU... do I have it right?
I'm not sure how you did the arithmetic :-) 4KW (8KB) is used for the "I/O
Page" which *includes* the boot PROMs. Stack can be anywhere.
> QUOTE:
> 0 000 000 001 ddd ddd -- JMP JuMP
>
> Loads the destination address into the PC, thus effecting an
> unconditional jump.
> Why is the jump destination address only six bits long?
> Jeesh, I hope I'm not asking the obvious....
Because the DDD DDD specifies a register (1 of 8) and address mode (1 of 8) to
use. So, you'll often see something like JMP @#0173000, which is represented
in two words 000137,173000. In this example, the address mode is 3
(auto-increment deferred, deferred = indirect) and the register to use is R7,
which is the PC.
So it means "jump to the address given in the word the PC points to". In other
words, that's how you code an absolute jump. The reason for the auto-increment
is that that mode is the general way of getting immediate data, and in the
general case you do need to increment the PC after the read (think about MOV
R0, @#0173000, opcode 010037,173000 which stores R0 in 173000).
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
Yeah, but could such a thing be done on Linux/UNIX OS's? I'm guessing that
you would need a NT server... and I don't like NT servers. I actually had a
NT and Linux server running on the exact same machine, at different times.
NT was harder to handle, and had more crashes just when I needed it most,
with many requests. Also, I had to reboot it 8 times to get it set up with
my video card, but not other cards, altogether, it took 16 reboots, compared
to 1 with Linux. My NT 5.0 beta is showing some signs of hope, but I'll
need a lot more before trusting NT with a hobby list as important as this
one.
Just my 0.02
Tim D. Hotze
-----Original Message-----
From: Richard A. Cini <rcini(a)email.msn.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Saturday, April 11, 1998 4:29 PM
Subject: Re: Thoughts about a Classiccmp private newsgroup
>On Fri, 10 Apr 1998 09:49:03 -0700 (PDT), Sam Ismail <dastar(a)wco.com>
wrote:
>
>On Fri, 10 Apr 1998, Richard A. Cini wrote:
>
>> Anyway, as part of my Microsoft beta testing, I belong to a small
>group
>> of "elite" testers. Called ClubWin!, we have a private administrative
>> newsgroup that requires a login name and password. Having a ClassicCmp
>> newsgroup would provide a threaded conversation capability. We could also
>> hang an e-mail gateway off of the news server to provide e-mail messages
>for
>> those who can't or want to use a newsgroup.
>
>
>>>Give us more details, Richard.
>
> Well, since I wasn't the one who implemented the news server, I'm only
>guessing as to its implementation. You can probably hang a NNTP (news)
>server off of any Internet-accessible server. The news server has its own
IP
>address. Bill Whitson could create one off of the ClassicCmp server at
>UofWA, or anyone else here with a free IP address and the approval of the
>bosses. You could then also provide an e-mail gateway the news server so
>that those who want the newsgroup activity by e-mail can get it.
>
> Authentication is either anonymous or login required. Each of us is
>given a login name and password (like rcini and 12345678), which will be
>required to logon. From there, your newsreader takes over.
>
>Rich Cini/WUGNET
> <nospam_rcini(a)msn.com> (remove nospam_ to use)
> ClubWin! Charter Member (6)
> MCP Windows 95/Windows Networking
>============================================
>
>
>
>
Hi Pete,
----------
> From: Pete Turnbull <pete(a)dunnington.u-net.com>
> To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
> Subject: Re: gcc for VAX VMS
> Date: Saturday, April 11, 1998 8:33 AM
>
> does DECUS do in other countries? There must be lots of peopel like us
who
> keep old 11s and VAXen running.
probably they don't use VMS ... ;-))
but serious, i think they expanding this Hobbiist thing to other countries.
one day ....
cheers,
emanuel
Wait a second, ARE there private newsgroups on this topic? I thought
it was just an idea everyone proposed but never did...
>
>At 08:49 AM 4/10/98 -0400, you wrote:
>> Scanning today''s messages gave me an idea. I don't know if this
has
>>been discussed before, but I don't remember it being discussed.
>
>It has. It comes up every now and then on every mailing list. What
>usually happens is that those who want a newsgroup go off a create a
>newsgroup, and the ones who can't access or don't like newsgroups stick
to
>the e-mail list, and the real die-hards follow both, cross-posting
stuff
>all the time.
>
>> ClubWin! Charter Member (6)
> ^
>I am not a number, I am a free man!
>
>
>---------------------------------------------------------------------
O-
>
>Uncle Roger "There is pleasure pure in being mad
>roger(a)sinasohn.com that none but madmen
know."
>Roger Louis Sinasohn & Associates
>San Francisco, California
http://www.sinasohn.com/
>
>
>
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
On Apr 11, 17:06, Hotze wrote:
> Subject: Re: Thoughts about a Classiccmp private newsgroup
> Yeah, but could such a thing be done on Linux/UNIX OS's? I'm guessing that
> you would need a NT server...
You can run the INN server under linux (or other UNIXes), and it supports
authorisation. I'd expect that the real problem is finding the extra space to
store the newsgroup files. At present, I don't think the list takes up much
file space, since the postings aren't archived (AFAIK).
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
Hi Pete,
----------
> To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
> Subject: Re: gcc for VAX VMS
> Date: Saturday, April 11, 1998 4:54 AM
>
> Now, can someone remind me of the URL for VMS hobby licensing so I can do
> something about my MicroVAX?
>
have a look at:
http://www.montagar.com/hobbyist/register.html
cheers,
emanuel
On Apr 11, 8:30, emanuel stiebler wrote:
> > From: Pete Turnbull <pete(a)dunnington.u-net.com>
> > Now, can someone remind me of the URL for VMS hobby licensing so I can do
> > something about my MicroVAX?
>
> http://www.montagar.com/hobbyist/register.html
> P.S. You have to be a DECUS member for this, ....
Thanks! I also see that it only covers a few countries -- not including the
UK, where I am. I let my UK DECUS membership lapse, when they started charging
considerable (at least, from a student's point of view) amounts of money for
annual membership and vast amounts of money for software from the library.
It's not like in the States, where there's a no-charge Basic Membership. What
does DECUS do in other countries? There must be lots of peopel like us who
keep old 11s and VAXen running.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
Hi Pete,
----------
> From: Pete Turnbull <pete(a)dunnington.u-net.com>
> To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
> Subject: Re: gcc for VAX VMS
> Date: Saturday, April 11, 1998 4:54 AM
>
>
> Now, can someone remind me of the URL for VMS hobby licensing so I can do
> something about my MicroVAX?
please have a look at:
http://www.montagar.com/hobbyist/register.html
cheers,
emanuel
P.S. You have to be a DECUS member for this, ....
On Fri, 10 Apr 1998 09:49:03 -0700 (PDT), Sam Ismail <dastar(a)wco.com> wrote:
On Fri, 10 Apr 1998, Richard A. Cini wrote:
> Anyway, as part of my Microsoft beta testing, I belong to a small
group
> of "elite" testers. Called ClubWin!, we have a private administrative
> newsgroup that requires a login name and password. Having a ClassicCmp
> newsgroup would provide a threaded conversation capability. We could also
> hang an e-mail gateway off of the news server to provide e-mail messages
for
> those who can't or want to use a newsgroup.
>>Give us more details, Richard.
Well, since I wasn't the one who implemented the news server, I'm only
guessing as to its implementation. You can probably hang a NNTP (news)
server off of any Internet-accessible server. The news server has its own IP
address. Bill Whitson could create one off of the ClassicCmp server at
UofWA, or anyone else here with a free IP address and the approval of the
bosses. You could then also provide an e-mail gateway the news server so
that those who want the newsgroup activity by e-mail can get it.
Authentication is either anonymous or login required. Each of us is
given a login name and password (like rcini and 12345678), which will be
required to logon. From there, your newsreader takes over.
Rich Cini/WUGNET
<nospam_rcini(a)msn.com> (remove nospam_ to use)
ClubWin! Charter Member (6)
MCP Windows 95/Windows Networking
============================================
On Fri, 10 Apr 1998 09:43:19 -0700 (PDT), Sam Ismail <dastar(a)wco.com> wrote:
>>Even if everyone could agree on this it would last for about 1 week and
>>then go back to status quo. I really don't mind the ads. They are not
>>excessive, they are reaching a good market where there is a win-win (the
>>seller gets some money and space back and the buyer gets first crack at
>>cool stuff), and they are more on topic than the drivel that has been
>>plaguing us for the last four weeks or so.
Whether or not it would go back would depend on our level of commitment.
I don't think that it is burdensome lately, because some are concentrating
on slinging mud, but it would be nice to have them all in one place.
Reference so to speak.
Rich Cini/WUGNET
<nospam_rcini(a)msn.com> (remove nospam_ to use)
ClubWin! Charter Member (6)
MCP Windows 95/Windows Networking
============================================
I had looked in jameco's catalog before, and the prices seem rather high! $25
for a single mathco is outrageous. i remember they did/do sell system boards
that arent necessarily state of the art for 2-3 times a "normal" price. do
they still sell apple parts? mouser electronics (if still around) might have
parts cheaper.
In a message dated 98-04-11 06:13:39 EDT, you write:
<< >I realize that this may not quite reach the 10year mark, but not many
>people deal with even this old of hardware. (Is there a group out there
>for "obsolete" yet non-yet-classic hardware?)
10 years? Yes. The 80386 was designed in 1985, so the 387 couldn't be to
much later than that.
>I need to find somewhere to get many i387 chips. (I currently need about
>15 to 20 of them.) Anyone know the best place to start looking?
The EXACT place to look is Jameco, at http://www.jameco.com . In their
newest catalog, they list the 80387 (unter Integrated circuts and then under
Math Coprocessors), they have: (prices for the 10-99 range)
80387-33 $25.95
80387-40 $29.95
80387-16SX $34.95
"""""""""20"" $39.95
"""""""""25"" $44.95
I can give part #'s if you're interested.
Hope this helps,
Tim D. Hotze
>>
>I realize that this may not quite reach the 10year mark, but not many
>people deal with even this old of hardware. (Is there a group out there
>for "obsolete" yet non-yet-classic hardware?)
10 years? Yes. The 80386 was designed in 1985, so the 387 couldn't be to
much later than that.
>I need to find somewhere to get many i387 chips. (I currently need about
>15 to 20 of them.) Anyone know the best place to start looking?
The EXACT place to look is Jameco, at http://www.jameco.com . In their
newest catalog, they list the 80387 (unter Integrated circuts and then under
Math Coprocessors), they have: (prices for the 10-99 range)
80387-33 $25.95
80387-40 $29.95
80387-16SX $34.95
"""""""""20"" $39.95
"""""""""25"" $44.95
I can give part #'s if you're interested.
Hope this helps,
Tim D. Hotze
Without comment
enrico
Anonymous wrote:
>
> Are you a fucking idiot, Limey? Cut the damn crying on the mailing list or you might just open a message one day and have your whole machine become instantly erased...Not a threat, a promise.
--
========================================================
Enrico Tedeschi, 54 Easthill Drive, Brighton BN41 2FD, UK
Tel/fax(+01273) 701650 (24 hours) and 0498 692465 (mobile)
please visit my website at: <http://www.brighton-uk.com>
========================================================
At 08:18 PM 4/9/98 -0400, you wrote:
>>around and use the PC as a disk drive "server" for the C64, VIC20 and C128?
>>And that is only one thought.
>
>I believe that's already been done.
I know it's been done for 8-bit Atari's. (I've seen a 1200xl with built-in
hard-drive, using a pentium with big HD and CD as a peripheral...)
(Talk to Bob Wooley of the San Leandro Computer Club, San Leandro, CA.)
--------------------------------------------------------------------- O-
Uncle Roger "There is pleasure pure in being mad
roger(a)sinasohn.com that none but madmen know."
Roger Louis Sinasohn & Associates
San Francisco, California http://www.sinasohn.com/
> They are not CPU upgradable, but you can add expansion
> memory out to 16MB, an 8 port async serial board (thats the big DB
> connector that doesn't go anywhere) and a sync serial port.
Sorry, the big DB that doesn't go anywhere is used to add another MFM
hard disk. It contains the control and data signals for the second drive.
I've not seen the 8-port option, but I believe it plugs in place of the
color graphics board.
> The SCSI port was only supported for the TKZ50 tape drive, an
> old 95MB DLT type drive, although I think there was a 3rd party SCSI
> disk driver from Trimarchi (now out of business).
Gerhard Moeller (I believe that's his name) has hacked over the SCSI driver
for the MicroVAX 3100 to bring it up on the 2000. I've used the driver under
VMS 7.1 to speak to a tape drive (this gives me a nice little package to take on
travel; a 2000 with an RD32 and a TZ30). Since it's a full-up SCSI port driver,
it can be used to support anything VMS knows how to talk to; disks, tapes,
etc. I've heard of one fellow who is using a 2000 to burn CDs.
I suggest looking around on dejanews for discussion of Moeller's driver.
> The VAXstation had a
> graphics display for a non-standard monitor.
All 2000s include a monochrome display built into the motherboard. It is also
possible to add on a color display. Rumor has it that it is not impossible
to use both displays simultaneously, but I've never tried it (my color
monitors have died over the years).
Roger Ivie
ivie(a)cc.usu.edu
Nephew has acquired a Telex 181-GP dot matrix printer. I've looked on the
net, and it looks like Telex is all but gone. Any idea where I might find
documentation on this unit? I'm assuming it emulates a 5152, like almost
every other DM made in the 80's.
Kind of ironic, as we had a huge Telex facility here in Tulsa for years.
--
David Wollmann |
dwollmann(a)ibmhelp.com | Support for legacy IBM products.
DST ibmhelp.com Technical Support | Data, document and file conversion for IBM
http://www.ibmhelp.com/ | legacy file and media formats.
I recently acquired a Morrow Designs Pivot Model 2522 - Special,
serial number 31-0001488. Both the model number and serial number are
hand written on the manufacturer plate on the rear of this pc. It has
dual 5 1/4 " floppy drives and 640k memory. The memory board is
labelled Morrow Zenith.This is an interesting portable having a rom
monitor for the built-in modem, what appears to be a built-in
calculator (haven't been able to get the calculator button to do
anything). Date can be changed in the monitor by pressing a button
also. Boots MS-DOS fine.
I read in Stan Veit's book that Zenith licensed this technology from
Morrow. Does anyone have any further info on this unit or better yet a
operation manual?
Thanks-
Marty Mintzell
Today I bought three portable PCs marked "Rabbit 286". They're about
the size of a large lunch box and have a keyboard that fastens against one
side. When you remove the keyboard it uncovers a gas plasma screen. There
are slots for two 3.5 drives on the right hand side and a door on the left
side. Opening the door exposes the back of several expansion card slots.
There's a label on the bottom that says "Chicony Electronics Co.", "Model
286G-A", "Gas Plasma Display" and "640H x 400W Dots". One almost works, one
is dead and the third one is somewhere in between. Does anyone know
anything about these? I'm wondering if it's possible to put a small 386 or
486 mother board in these.
Joe