22 Mar
2005
22 Mar
'05
7:06 p.m.
Thanks for the suggestions. The 79 cutoff is
really because I have a modest but working
collection of machines from 1980-1990 (UNIX
workstations) so I've got that covered.
I thought I'd turn my attention to pre 1980's
hardware before it becomes really difficult
to track down and PDP is probably the obvious
choice.
The 11/34 looks a good choice at this stage?
Regards
Ian.
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22 Mar
22 Mar
7:13 p.m.
On Tue, 2005-03-22 at 16:06 -0800, silvercreekvalley wrote:
I have a modest but working
collection of machines from 1980-1990 (UNIX
workstations) so I've got that covered.
Anything interesting? (by interesting I mean strange / unusual - I'm
sure they're all interesting to you or you wouldn't have them!)
Good luck with the PDP hunt!
cheers
Jules
7:54 p.m.
On Tue, 22 Mar 2005 16:06:47 -0800 (PST), silvercreekvalley
<silvercreekvalley at yahoo.com> wrote:
I thought I'd turn my attention to pre 1980's
hardware before it becomes really difficult
to track down and PDP is probably the obvious
choice.
For 1970s PDPs, the easiest to aquire would be something in a PDP-11
or PDP-8. Since you want a unix-like OS with a C compiler, that
pretty much pushes out the -8.
The 11/34 looks a good choice at this stage?
11/34s are among the cheapest PDP-11s from the 1970s (presuming you
don't get a haul-it-away deal). The CPU, memory, and some peripherals
fits in one BA-11 cabinet (10.5" tall, 19" wide, rack depth), but one
can add a second BA-11 if one really needs more than 3 backplanes.
The max memory is 256K (18-bit addressing), which is enough for
something like a v7 or a XINU, but would be a bit cramped for 2.9BSD.
Disks are probably going to be your biggest problem... the RK05 was a
common disk in the 11/34 era, at 2.5MB per drive (4 drives per
controller). v7 might fit, but 2.9BSD will be _really_ cramped.
RL02s may be easier to locate, but they are 1980s tech essentially,
and even at 10MB, are a bit on the small side for UNIXy work (but are
great for RT-11, etc.)
I never did solve my Unibus disk issue for non-MSCP disks... UDA50s
are not impossible to find, but the disks tend towards the heavy side
compared to, say, ESDI disks. It matters less to me than it used to,
since it's possible now to use MSCP disks with 2.9BSD (formerly, one
had to go to 2.11, and that required a split I&D machine, of which I
have few).
If an 11/23 is not too new (it might be 1979), it's a nice choice
because a) it's 22-bit (except for rev A boards)allowing up to 4Mb of
RAM, b) it _is_ compact, c) it's expensive, but a Qbus SCSI card is
easier to find than a Unibus SCSI card. They are also somewhat common
(I got my first one in 1986 for a whopping $300, then used that to do
work on a contact that was my bread and butter for two years)
An 11/23 w/RLV11 (requires CD-capable backplane) or RLV21 and a couple
of RL02s is a nice PDP-11 system, and fits in a 42" tall rack. Not
sure you could get all of that for under a grand these days, but it's
a place to start.
-ethan
8:04 p.m.
For 1970s PDPs, the easiest to aquire would be
something in a PDP-11
or PDP-8. Since you want a unix-like OS with a C compiler, that
pretty much pushes out the -8.
I also have a nice working 11/23 that I'm thinking about selling. I can
put it in a short rack with an RL02 drive. It already has the controller
for the RL01/RL02 drives, as well as the RX02 controller. It has a
multiplexer, so you could run multiple terminals if you wanted to.
I can also configure the 11/34A with a DZ11 multiplexer, if you want to
run multiple terminals on a unibus machine.
If you (or anyone else) is interested in either the 11/34A or the 11/23,
contact me off-list.
Thanks,
Ashley
wacarder at usit.net
The 11/34 looks a good choice at this stage?
11/34s are among the cheapest PDP-11s from the 1970s (presuming you
don't get a haul-it-away deal). The CPU, memory, and some peripherals
fits in one BA-11 cabinet (10.5" tall, 19" wide, rack depth), but one
can add a second BA-11 if one really needs more than 3 backplanes.
The max memory is 256K (18-bit addressing), which is enough for
something like a v7 or a XINU, but would be a bit cramped for 2.9BSD.
Disks are probably going to be your biggest problem... the RK05 was a
common disk in the 11/34 era, at 2.5MB per drive (4 drives per
controller). v7 might fit, but 2.9BSD will be _really_ cramped.
RL02s may be easier to locate, but they are 1980s tech essentially,
and even at 10MB, are a bit on the small side for UNIXy work (but are
great for RT-11, etc.)
I never did solve my Unibus disk issue for non-MSCP disks... UDA50s
are not impossible to find, but the disks tend towards the heavy side
compared to, say, ESDI disks. It matters less to me than it used to,
since it's possible now to use MSCP disks with 2.9BSD (formerly, one
had to go to 2.11, and that required a split I&D machine, of which I
have few).
If an 11/23 is not too new (it might be 1979), it's a nice choice
because a) it's 22-bit (except for rev A boards)allowing up to 4Mb of
RAM, b) it _is_ compact, c) it's expensive, but a Qbus SCSI card is
easier to find than a Unibus SCSI card. They are also somewhat common
(I got my first one in 1986 for a whopping $300, then used that to do
work on a contact that was my bread and butter for two years)
An 11/23 w/RLV11 (requires CD-capable backplane) or RLV21 and a couple
of RL02s is a nice PDP-11 system, and fits in a 42" tall rack. Not
sure you could get all of that for under a grand these days, but it's
a place to start. 
8:47 p.m.
Disks are probably going to be your biggest problem...
the RK05 was a
common disk in the 11/34 era, at 2.5MB per drive (4 drives per
controller). v7 might fit, but 2.9BSD will be _really_ cramped.
Actaully 8 drives per controller, but even so it's crampped. And 8 RK05
drives take up a heck of a lot of space!
RL02s may be easier to locate, but they are 1980s tech
essentially,
and even at 10MB, are a bit on the small side for UNIXy work (but are
great for RT-11, etc.)
What abnot the RK06/RK07 (14MB and 28MB per drive repsectively, I think,
up to 8 drives per controller). Probably actually 1980's units, but still
top-loading demountable drives, 2 platters in the pack (3 data surfaces,
1 servo surface). Electronics is loads of simple chips (TTL, op-amps,
etc). If you understand the servo in one of those, you've got somewhere ;-)
If an 11/23 is not too new (it might be 1979),
it's a nice choice
because a) it's 22-bit (except for rev A boards)allowing up to 4Mb of
RAM, b) it _is_ compact, c) it's expensive, but a Qbus SCSI card is
easier to find than a Unibus SCSI card. They are also somewhat common
(I got my first one in 1986 for a whopping $300, then used that to do
work on a contact that was my bread and butter for two years)
Be aware that the 11/34 (And the 11/35, 11/40, 11/45 that others have
recomended) are traditional 1970's designs, all TTL and small PROMs. The
11/23 is an LSI design with the CPU in a few DEC custom ICs. This is a
real minus point against the 11/23 for me.
-tony
10:17 p.m.
Tony said:
Actaully 8 drives per controller, but even so it's crampped. And 8 RK05
drives take up a heck of a lot of space!
and don't forget that they weigh about 125 pounds apiece. 8 RK05s is
about a half ton! I used to pick up those RK05s off the floor and rack
them myself until I found out what that does to a 47-year old back. I
was in the bed for almost the entire month of November from injuring my
back lifting RK05s and racking them by myself!
Ashley
23 Mar
23 Mar
6:07 p.m.
Tony said:
Actaully 8 drives per controller, but even so it's crampped. And 8 RK05
drives take up a heck of a lot of space!
and don't forget that they weigh about 125 pounds apiece. 8 RK05s is
about a half ton! I used to pick up those RK05s off the floor and rack
them myself until I found out what that does to a 47-year old back. I from the top downwards, when you get the electronics,
disk housing, etc
out of the way, the main chassis, complete with spindle, spindle
motor,
positioned, etc, comes out with just 3 bolts. The base pan is quite easy
to lift onto the stand, agqain it all goes back together in a few minutes.
And the RA60. A fried delivered one using his pick-up truck (a 1947
Fordson IIRC). I took one look at it (the drive) and decided there was no
way I could get that thing into the house and upstairs on my own. So I
grabbed the toolkit and took it apart on the back of the truck. Again,
the main chassis comes out with little work and is liftable, so is the
casing and the various electronic parts.
-tony
7:23 a.m.
New subject: What are they worth? was Re: Which PDP?
Ethan Dicks wrote:
An 11/23 w/RLV11 (requires CD-capable backplane) or
RLV21 and a couple
of RL02s is a nice PDP-11 system, and fits in a 42" tall rack. Not
sure you could get all of that for under a grand these days, but it's
a place to start.
-ethan
I've got an OEM 11/73, with (mostly) OEM cards, originally built by
Baydel. It's got a couple of ST506 drives, probably about 30M each, and
two RL02s plus a spare drive, and about a dozen carts. There's quite a
lot of interesting software.
I suspect I got a good deal - it cost me a 19" Sun monitor and some
beer. Any idea how much that's worth? As far as I can tell, it's about
as good a PDP-11 system as you're going to get into the back of a large
hatchback...
Gordon.
11:19 a.m.
New subject: What are they worth? was Re: Which PDP?
Gordon JC Pearce wrote:
I've got an OEM 11/73, with (mostly) OEM cards, originally built by
Baydel. It's got a couple of ST506 drives, probably about 30M each,
and two RL02s plus a spare drive, and about a dozen carts. There's
quite a lot of interesting software.
I suspect I got a good deal - it cost me a 19" Sun monitor and some
beer. Any idea how much that's worth? As far as I can tell, it's
about as good a PDP-11 system as you're going to get into the back of
a large hatchback...
But alot of you collectors got the machines since you knew about what to
collect at the right time
and place. I still dind it intersting the 11 is still going strong and
the all the other bigger DEC machines
and workstations are much less popular for collecting. Also living in
Canada does have shipping problems
so even if a real 11* showed up that I could afford I could never get it
here.
Gordon.
Ben alias woodelf
* Something that is not crippled do to marketing factors.
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ard＠p850ug1.demon.co.uk -
bfranchuk＠jetnet.ab.ca -
ethan.dicks＠gmail.com -
gordon＠gjcp.net -
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