David Riley <fraveydank at gmail.com> wrote:
> Well, you *could* work around it that way. I guess Kapton would
> probably be a good bet. You're very unlikely to be using early LSI-11
> boards unless you're a true masochist (...)
Uhm, people have already been calling me that (in a classiccmp context!), so...
> Be aware that if you're using the system as 18-bit, you'll
> need to make sure that your peripheral cards are jumpered to 18-bit if
> necessary (boards that use DMA often need to know).
> The 22-bit conversion is also easy to undo, assuming you're handy with
> a soldering iron (...) For me, undoing that would be about as easy as looking up
> which pins to cover and then covering them with tape (...)
Hmm, I'm just "planning for eventualities"; Basically I want to build a system that runs in a 22-bit configuration, but I'm trying to make sure I can still stick in 18-bit CPUs (or other cards) for a quick test after I do the conversion.
>> (or custom logic, if you had that).
> Sounds interesting, could you elaborate?
>
> (...) There were probably quite a few other board sets that used
> the CD lines for inter-board communication (...)
> (very nice description of CD interconnect principles)
Definitly an option I would want to keep. Too bad there aren't any 9-slot mixed layout backplanes, but as DEC compatible backplane connectors seem to surface sometimes, so I see at least the possibility of constructing one, should the need materialize.
> I wouldn't swear to the fact that there weren't 11/23s sold as 18-bit
> systems; my fuzzy memory says that 11/23 might have been 18-bit while
> 11/23+ would have been 22-bit. Other people doubtless know better
> than me; my other recollection is that the "plus" distinction has to
> do with the KDF11-B board (which has the boot ROM and SLUs).
Christian Gauger-Cosgrove <captainkirk359 at gmail.com> wrote:
> I don't know anything about how DEC sold their machines, but I do believe
> they did sell the 11/23 as an 18-bit system (even though the KDF11A is very
> much capable of 22-bit) (...)
Hmm, let's see...
>From http://www.people.vcu.edu/~agnew/MVAX/9412_DECUSERVE_JNL.HTML
(supposedly extracted from Micronote #5 dated 23-Apr-84):
> RESTRICTED COMPATIBILITY OPTIONS:
>
> PROCESSORS:
>
> KDF11-A M8186 LSI-11/23 CPU
> Prior to etch rev. C, 18-bit addressing only,
> and use of BC1, BD1, BE1, BF1 for purposes
> other than BDAL18-21.
...so the systems using these earlier revisions, while being 11/23s by definition, would have to be based on 18-bit backplanes due to the nonstandard signals. This is also consistent with Christian's statement:
> as I remember there is a "PDP-11/23" version of
> the BA11-N box (with H9273-A, the BA11-N always has the H9273-A)
I think I actually might be having the remains of such an early system, as it says "11/23" on the outside but holds an (18-bit) H9273 backplane inside.
Alas I haven't readily found a DEC source on what actually is the PLUS in an 11/23+.
Thank you so far,
Arno
------ Original Message ------
From: "Enrico Lazzerini" <enrico.lazzerini at email.it>
To: cctech at classiccmp.org
Sent: 04/04/2013 18:15:52
Subject: Chip 733w01522 on xerox 820-II FDC controller. what is it?
>Is there anybody who knows what is this old chip? And where to try to
>find
>it?
I believe that its a 74S288 which is 256 bit PROM (32x8) bit prom. So
even if you find one you need to know its contents. Look for an
application note for the 1297.
>
>If it help what I know is that it used to do somenting like shift data
>register or Serial Shift Registers.
>
Often used for state decoding. From searching the web I can see that
there is an FE2100 which is designed to replace the discrete logic on a
FDC board and it mentions the 74S288..
>It has a TTL level signal on its pins, it has 14 pins. You can see it
>named
>U1 in the centre of this schematic:
><https://www.dropbox.com/s/zqhgar4g7ib5j4z/Xerox820_FDC_Schematic.pdf>
>https://www.dropbox.com/s/zqhgar4g7ib5j4z/Xerox820_FDC_Schematic.pdf
>
>
>
>Some pins are labelled on a schematics with:
>
>1=D1, 2=D2, 3=D3, 4=D4,
>
>10=A1, 11=A2, 12=A3, 13=A4, 14=A4,
>
>15=ChipEnable (left to GND),
>
>7=GND,
>
>14=+5Vcc
>
>
these match the chip outline in my Texas TTL manual (there are 4 more
data outs which are unused in this application)
>
>Thanks
>
>Enrico
>
Sorry not 100% of needed info
Dave
G4UGM
Jon Elson wrote:
> Date: Thu, 04 Apr 2013 22:29:04 -0400
> From: Toby Thain <toby at telegraphics.com.au>
> To: cctalk at classiccmp.org
> Subject: Re: VAX 11/780
> Message-ID: <515E36F0.5040101 at telegraphics.com.au>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> On 04/04/13 9:32 PM, Jon Elson wrote:
>
>> > From: Brian Roth <abacos_98 at yahoo.com>
>> > To: "cctech at classiccmp.org" <cctech at classiccmp.org>
>> > Subject: VAX 11/780
>> > Message-ID:
>> > <1365090232.96105.YahooMailNeo at web141403.mail.bf1.yahoo.com>
>> > Content-Type: text/plain; charset=us-ascii
>> >
>> >
>> > I just recently acquired a very nearly complete VAX 11/780. I will
>> > be spending the next few months in a partial tear down and cleaning
>> > and with luck, hopefully little money to get it operational again. I
>> > ...
>>
>> >
>> > Good luck restoring this machine!
>>
>
>
>
> Seconded. I hope you will blog/document the whole process. I own an
> 11/750 but haven't started restoring it.
>
> --Toby
>
> One huge advantage to the 780 is there are almost no custom parts in
> it, other than
> the LSI-11 which is still pretty much available, if needed. The whole
> 780 CPU
> was built out of 74Sxx chips, and could probably be maintained for another
> 50 years if one wanted to. The only custom sort of parts would be in the
> power supplies, which would be easy to swap out with generic DC supplies
> if you couldn't repair them.
>
> Jon
The RICM has the processor of their PDP-9 working fairly well. We have most
of the diags for the processor on paper tape. We will make working copies
of the tapes and also make images to send to Bitsavers. We have the diag
documentation for the TC59/TU20, but we do not have the paper tapes. It
would be possible to enter the source from the listing and assemble it
using Simh, but that would be a bit of work.
I know that it is probably wishful thinking, but does anyone have paper
tapes of the TC59/TU20 diags?
Paper tapes of the TC02/TU55 diags would be nice to have too.
We would eventually like to get an OS running on the system. It looks like
the ADSS Input/Output Monitor will run on our configuration, and maybe even
the Keyboard Monitor.
Does anyone have paper tapes for ADSS or any other monitor that would run
on this system?
Details of the paper tapes and manuals that we have are at the bottom of
this page:
http://www.ricomputermuseum.org/Home/equipment/dec-pdp-9
--
Michael Thompson
Trying to rebuild the FDC card by my xerox 820-II motherboard, I have
discovered the presence of an IC named 733w01522 (U1) on the photo of the
original PCB which code I cannot read on the schematic not very readable
reported at the end of xerox820-II service manual.
Sorry, I mistakenly indicated a 14-pin TTL chips even though it was 16 pin.
Thanks for contribution of Chuck Guzis from the VCF he told me that the
733w01522 is a PROM and it is equivalent at 74S288 but also to others IC as
reported here http://www.hobbyroms.com/proms.html.
U1 (74S288) and U2 (74S174) together constitute a "finite state machine" (so
they told to me cause I'm not so expert) whose purpose is to provide a read
clock and a read data to the chip WD1797 from raw data received from the
drive.
Then I need to discover the code that the chip could have (without having
the original chip programmed with me!).
Upon the recommendation of Chuck Guzis I found the code listing on page 12
of the manual of the FDC1797's application notes. At this point, trusting to
this code I'd need to buy a programmed 74S288 (or equivalent).
After all this I was finally trying to figure out if it sould be better to
use of a schematic published on an old issue of Microcornucopia:
https://www.dropbox.com/s/4f8kblogrlzdr9m/FDC_from_Micro_Cornucopia_#22_Feb8
5.pdf.
Who wrote that article decided to build itself a FDC controller card for his
xerox 820-II extracting a block of its schematic from a Kaypro-II's
schematic really making very few changes and using a FDC WD1793 + WD9216 for
external separator data.
Due to its small number of components, and having already a WD1797 I'd just
need of a WD9216 (i hope to find it on the Internet yet) and wiring it would
be maybe more simple.
Last suggestion (always from the so expert Chuck that I thanks so much)
would be to use a WD2797 instead of WD1797, but I'm not a designer and while
i can understand something of all those things it's very hard for me to
change schematics or adjust components.
I hope to be able to buy a ready Xerox 820-II FDC board even I know that
it's not very easy to find. Thanks anyway for all the support that was given
to me.
Regards
Enrico - Pisa (ITALY)
Hah, a thread just in time for me!
Hello fellow collectors.
I got the card-less carcass of a pdp-11/23 (says so on the front and back type labels) some weeks ago.
This is going to be my first pdp ever so please be a bit patient with me :)
It is the BA11 variety and contains a H9273 backplane, which as far as I could find out is QQ-CD
(consistent with your statement below).
However the backplane has a sticker on it which is stamped "11/03" (?!)
So what kind of CPU (or more generally, kinds of boards) am I looking for to populate this puppy?
I've already done some reading on DEC stuff from bitsavers and gleaned that in order to make it an
11/23, it would have to hold either an M8186 (KDF11-A) or an M8189 (KDF11-B) processor.
As the M8186 only comes in a dual slot form factor, it clearly can't make use of the CD
interconnect on the backplane. The M8189 is a quad-width board, but with the CD part configured
for a serpentine backplane (the manual mentions two jumpers to be removed when using in another
environment to avoid shorting signals together), so again no "meaningful" use of the CD lanes.
What are these intended for anyway (I was thinking of some sort of PMI predecessor, probably
wrong by now), and what boards do I need to take advantage of them in this machine?
Also, are there any ressources online about the Q-22 upgrade? I might need do do that because I
already was promised a 512kw MOS memory board by another German collector.
TIA, yours sincerely
Arno
Pete Turnbull <pete at dunnington.plus.com> wrote:
Indeed, or as Jerome suggested, looking at the configuration of the
cards may give you a clue. So would the type of box: if it's a 3U-high
(5.25") grey-fronted-metal-panel rack-mount box with three toggle
switches, it's a BA11-N or BA11-S, which have straight backplanes (and
are all QQ-CD), if it's a small tabletop box or a 2U (3.5") it's a
BA11-V (tabletop) or BA11-M (2U) which have serpentine backplanes, and
if it's a floor-standing microPDP-11 (or microVAX) box or a chassis with
four or six pushbuttons on the front, it's a BA23 box which is QQ-CD in
the top slots and serpentine below.
Or count the card slots. All 9-slot backplanes are straight. 8-slot
and 13-slot are mixed (for microPDP-11 and microVAX). Anything else is
serpentine.
BA11-M and BA11-V boxes are relatively uncommon. If it's a BA11-N,
although the backplane is 18-bit, it's very easy to upgrade to 22-bit.
>> -- which I understand can be serpentine,
All Q-Q backplanes are serpentine, and all straight backplanes are
QQ-CD. The only odd one is the hex-high DDV11-B, which is a serpentine
backplane in the ABCD positions and not bussed at all (except for power
in the standard contact positions) in EF - it's meant for custom wiring.
Of course we're assuming it's a DEC box with a DEC backplane. A
Plessey backplane, for example, might be different, but you'd probably
know if it was non-DEC, because it's pretty rare to find DEC's dark
green connectors on anything non-DEC. Plessey and GEC ones, again for
example, are white.
--
Pete Peter Turnbull
Network Manager
University of York
This is a stretch, but I figured I'd ask: anyone have any spare
6540-series PET ROMs lying around? After diagnosing a number of other
failures, Ialmost have my (very beat up) chicklet-keyboard PET working,
but it looks like the -026 ROM (at F800-FFFF) has gone south -- it has a
few corrupted bits here and there. It looks like adapters to fit
standard 2716s are available to build, but before I invest time and/or
money in one of those I thought I'd ask around.
Thanks as always,
Josh
Does anyone have a good-condition, second-generation (working +
non-yellowed) //e Platinum they'd consider selling to me? There are a
few Platinums on eBay but I am leery of going that route.
(Platinum is the model with the numeric keypad. There were two versions:
the first gen in standard Apple II beige, and the second gen in a gray
color -- that's the one I want.)
Date: Fri, 05 Apr 2013 16:06:58 -0400
From: Dave McGuire <mcguire at neurotica.com>
To: General Discussion: On-Topic and Off-Topic Posts
<cctalk at classiccmp.org>
Subject: Re: VAX 11/780
Message-ID: <515F2EE2.6020902 at neurotica.com>
Content-Type: text/plain; charset=ISO-8859-1
On 04/05/2013 03:37 PM, Brian Roth wrote:
> >
> > Agreed. The one place I am going to start is with the power supplies. I plan on running this on
> > single phase at least initially. I don't see anything in there that needs 3 phase.
>
The blowers?
Nope, the entire machine is built from single-phase components.
The power supplies even have wall plugs on them, and are powered through
what are essentially the female end of extension cords. (I think they
run off 208 V, but maybe they were running L-N off of 120 V.)
The blowers were 208/230 V single-phase motors, you could hear the
centrifugal switches drop back in when you shut the machine off.
The power distribution wiring would have to be hacked for single-phase
operation, hopefully the power supplies can be run off 240 V without
harm.
The TU77 may be a problem, I vaguely recall that may have a 3-phase
motor for the vacuum blower/air bearing pump. Today, I'd get
a VFD and run the motor (ONLY) off synthetic 3-phase.
The RM07 also was 3-phase, I think all the smaller VAX 780
disks were single-phase. The RM07 was a total monstrosity
>from Burroughs, I hope you don't have one of those. We went through
a lot of pain as one of the early adopters of that, but in the
end it was a high performance drive and fairly reliable.
Jon