Re: DEC PDP-11/45 backplane +5 ECO
> On May 2, 2021, at 1:25 PM, Josh Dersch wrote: > > Sorry for the delay, but finally, here's a pile of pictures of the +5V ECO on > the backplane. Let me know if you need more detail on something: > > https://1drv.ms/u/s!Aqb36sqnCIfMpMAqf_6YvmsEEU-T0A?e=Y6WBfV Oh, this is great, thanks! It's very interesting to see how this was implemented. I think I will need empty my backplane soon in order to do some lower fan maintenance, so I will probably pull my backplane and implement this at that time.
Re: DEC PDP-11/45 backplane +5 ECO
On Sun, Apr 25, 2021 at 11:26 PM Fritz Mueller wrote:
>
> > On Apr 24, 2021, at 7:02 PM, Josh Dersch wrote:
> > If you have notes on re-creating the harness, let me know.
>
> Hi Josh,
>
> A few pointers -- I think I left some of these in a comment on one of your
> fb posts, but will repeat here in case others may find it useful:
>
> * The wire list in the commonly available Jun74 11/45 engineering drawing
> set is actually for the power harness, and not for the backplane. It
> includes wire run lengths in inches, which is quite handy. I believe it is
> for the newer harness, but there is much overlap.
>
> * The old and new harnesses are also schematically illustrated on four
> pages of the drawing set marked "power systems configuration". These
> drawings are complete and quite good.
>
> * Drawings for the power distribution board for the older wiring style
> (vertical at the back of the cabinet) are hidden in the Jun74 11/*40*
> engineering drawings (upper right of sheet BA11-F0).
>
> * What I did was use the wire list lengths as a guide, cutting each run to
> length plus a little extra. I then started with the H742s on the bench, at
> the regulator and power monitor mate-n-loks. Then put the H742s in the
> rack with the CPU cabinet, and worked my up and over the and then down
> along the along the backplane toward the console, bundling and trimming to
> length as I went.
>
> * A good ratchet lock crimp tool makes a big difference here. You want
> one with a die that can handle 14 AWG, and on which will crimp both the
> electrical and strain-relief parts of the pins in one go.
>
> * Sticking with the original wire color code also makes it a lot easier
> not to get lost and later to double check and troubleshoot your work. I
> used MTW ("Machine Tool Wire"), which is available from wirebarn.com at
> 14 and 18 AWG in most of the necessary colors and in 25 and 100 foot
> lengths (I think the 18 AWG purple I had to find separately on eBay, but I
> have lots of leftover of that and will gladly send you some.)
>
> * I skipped wiring for most of the regulators in the bottom H742 (I have
> regulator F there, but none of H, J, K, or L are populated) because I don't
> have any core or fastbus memory in my system. I figure I can add this
> later if I ever do find myself with either of these.
>
> Good luck!
>
Thanks! I may get started on that fairly soon, we'll see how ambitious I'm
feeling...
Sorry for the delay, but finally, here's a pile of pictures of the +5V ECO
on the backplane. Let me know if you need more detail on something:
https://1drv.ms/u/s!Aqb36sqnCIfMpMAqf_6YvmsEEU-T0A?e=Y6WBfV
- Josh
> --FritzM.
>
>
Re: DEC PDP-11/45 backplane +5 ECO
> http://bitsavers.org/pdf/dec/pdp11/1145/KB11-A_revS_Engineering_Drawings_Dec1973.pdf Thanks very much, Al!
Re: DEC PDP-11/45 backplane +5 ECO
On 4/28/21 10:19 AM, Fritz Mueller wrote: Ohh... I'd be very, *very* interested to see versions of the /45 drawings other than the two sets that are commonly available! http://bitsavers.org/pdf/dec/pdp11/1145/KB11-A_revS_Engineering_Drawings_Dec1973.pdf
Re: DEC PDP-11/45 backplane +5 ECO
On Wed, 28 Apr 2021, Fritz Mueller wrote: On Apr 28, 2021, at 9:51 AM, Al Kossow via cctalk wrote: I have other 45/70 drawings that i haven't pdf'ed I need to see if they are different revs than what I already have Ohh... I'd be very, *very* interested to see versions of the /45 drawings other than the two sets that are commonly available! I should fetch the drawings from my 11/45 from my parent's home the next time I visit them. I would then scan them regardless whether they are already available or not ;-) Christian
Re: DEC PDP-11/45 backplane +5 ECO
On 4/28/21 9:51 AM, Al Kossow via cctalk wrote: On 4/28/21 9:14 AM, Noel Chiappa via cctalk wrote: https://www.computerhistory.org/collections/catalog/102749003 so maybe Al will take pity on us and scan it! I'll see what I can do. I have other 45/70 drawings that i haven't pdf'ed I need to see if they are different revs than what I already have I've added two more RH drawings to the ones already under pdf/dec/unibus
Re: DEC PDP-11/45 backplane +5 ECO
> On Apr 28, 2021, at 9:51 AM, Al Kossow via cctalk > wrote: > > I have other 45/70 drawings that i haven't pdf'ed > I need to see if they are different revs than what I already have Ohh... I'd be very, *very* interested to see versions of the /45 drawings other than the two sets that are commonly available! I've been collecting/compiling detailed information about ECOs and board revs for the KB11-A (for example, the one that launched this thread!), and looking at diffs between the two available drawing sets has been a valuable technique for shaking out hints and clues about things otherwise undocumented. Having more to draw from here would be *super* helpful. A fairly complete summary of things puzzled out so far, for those of you with /45s who may be interested, is here: https://fritzm.github.io/ecos.html cheers, --FritzM.
Re: DEC PDP-11/45 backplane +5 ECO
On 4/28/21 9:14 AM, Noel Chiappa via cctalk wrote: https://www.computerhistory.org/collections/catalog/102749003 so maybe Al will take pity on us and scan it! I'll see what I can do. I have other 45/70 drawings that i haven't pdf'ed I need to see if they are different revs than what I already have
Re: DEC PDP-11/45 backplane +5 ECO
> On Apr 28, 2021, at 9:14 AM, Noel Chiappa via cctalk > wrote: > > ISTR a previous, un-fulfilled request for the -11/70 wirelist, so it's been > missing for a while. > > We _might_ have the -11/45 wirelist: > > > http://www.bitsavers.org/pdf/dec/pdp11/1145/1145_System_Engineering_Drawings_Jun74.pdf > > but it's short (pp. 128-132), so maybe it's not complete)? Two other > print sets seem to have the same list: > > > http://www.bitsavers.org/pdf/dec/pdp11/1145/1145_System_Engineering_Drawings_Jun76.pdf > http://www.bitsavers.org/pdf/dec/pdp11/1155/MP00039_1155vol1_Mar76.pdf > > (pp. 45-49 and pp 131-135 respectively). I've been looking for 11/45 backplane wire lists for many years, but have never found them. (Noel: the wire lists in the bitsavers 11/45 drawing sets are actually for the power harness, and not for the backplane.)
Re: DEC PDP-11/45 backplane +5 ECO
> From: Eric Smith > The KB11-B (original 11/70) and KB11-C (later 11/70) have essentially > the same changes as from the KB11-A to KB11-D Speaking of which, two of the boards that are different in the KB11-D, from the -A, are _identical_ to boards in the KB11-C - the M8123 ROM & ROM control and the M8132 instruction register decode! (The M8123 is also different from the M8133 board in the KB11-B.) Pretty wierd that the -11/45 and -11/70 CPUs share two boards, but true! (The FP11 boards are the same in both, too.) > It sure would be nice to get backplane wirelists for all four (KB11-A, > -B, -C, and -D). ISTR a previous, un-fulfilled request for the -11/70 wirelist, so it's been missing for a while. We _might_ have the -11/45 wirelist: http://www.bitsavers.org/pdf/dec/pdp11/1145/1145_System_Engineering_Drawings_Jun74.pdf but it's short (pp. 128-132), so maybe it's not complete)? Two other print sets seem to have the same list: http://www.bitsavers.org/pdf/dec/pdp11/1145/1145_System_Engineering_Drawings_Jun76.pdf http://www.bitsavers.org/pdf/dec/pdp11/1155/MP00039_1155vol1_Mar76.pdf (pp. 45-49 and pp 131-135 respectively). > Also, I'm looking for a Field Maintenance Print Set for the RH70. Heh. I didn't see it online; the manual: http://www.bitsavers.org/pdf/dec/unibus/CSS-MO-F-5.2-27_RH70_Option_Description_Feb77.pdf is a CSS document, which makes no sense, because the CPU backplane is laid out to have room for four, so it's an integral part of the /70 CPU - so why is it a CSS product? Anyway, the print set listed there seems like it might be a CSS thing, too. I see that the CHM seems to have a set: https://www.computerhistory.org/collections/catalog/102749003 so maybe Al will take pity on us and scan it! I looked in my /70 print set, and although it contains all sorts of odds and ends (including MJ11 prints - which kind of half makes sense, since that was the only main memory option on early /70's), it doesn't have the RH70. (I didn't see the MJ11 prints on BitSavers, so I was thinking I was going to have to scan them, but on further looking I found them on deramp.com.) Noel
RE: DEC PDP-11/45 backplane +5 ECO
Van: Noel Chiappa via cctalk<mailto:cctalk@classiccmp.org> Verzonden: woensdag 28 april 2021 16:08 Aan: cctalk@classiccmp.org<mailto:cctalk@classiccmp.org> CC: j...@mercury.lcs.mit.edu<mailto:j...@mercury.lcs.mit.edu> Onderwerp: Re: DEC PDP-11/45 backplane +5 ECO > From: Henk Gooijen > I have the M8120 and 4 M8121 boards (32kW bipolar RAM). It is a bit > weird, but in the 11/55 are also two G114 boards (4kW MOS RAM), IIRC. G114s? Those are the sense/inhibit module from the MM11-U/MJ11. Did you mean G401s? If so, one guess as to what happened there is that the machine used to have two banks of MS11 Fastbus memory, one bipolar, and one MOS, and some of the boards from the MOS bank (the memory control, and maybe some of the matrix boards) got removed? A KB11-[AD] can have two banks of MS11; the only type mixing allowed is that one can be all bipolar, and one all MOS; within each bank they all have to be the same. More here: https://gunkies.org/wiki/MS11_Semiconductor_Memory_System Interesting factoid: the M8110 and M8120 use the same etch. I'm not sure quite what the difference is (the MS11-A MM doesn't say, I couldn't find, and I don't think we have the M8120 engineering drawings, just the M8110); the M8120 has a bunch of ECO wires on it, and maybe there are component changes too. (I don't have an M8110 to compare them directly.) Noel Thanks for the correction Noel. I “knew” that G114 was not correct Indeed, G401 is better! One day, I will work on the /45 eand /55 … Henk
Re: DEC PDP-11/45 backplane +5 ECO
> From: Henk Gooijen > I have the M8120 and 4 M8121 boards (32kW bipolar RAM). It is a bit > weird, but in the 11/55 are also two G114 boards (4kW MOS RAM), IIRC. G114s? Those are the sense/inhibit module from the MM11-U/MJ11. Did you mean G401s? If so, one guess as to what happened there is that the machine used to have two banks of MS11 Fastbus memory, one bipolar, and one MOS, and some of the boards from the MOS bank (the memory control, and maybe some of the matrix boards) got removed? A KB11-[AD] can have two banks of MS11; the only type mixing allowed is that one can be all bipolar, and one all MOS; within each bank they all have to be the same. More here: https://gunkies.org/wiki/MS11_Semiconductor_Memory_System Interesting factoid: the M8110 and M8120 use the same etch. I'm not sure quite what the difference is (the MS11-A MM doesn't say, I couldn't find, and I don't think we have the M8120 engineering drawings, just the M8110); the M8120 has a bunch of ECO wires on it, and maybe there are component changes too. (I don't have an M8110 to compare them directly.) Noel
Re: DEC PDP-11/45 backplane +5 ECO
Wait, that 11/45 looks to have an MS11-LK memory board in it. I assume that's just normal slow Unibus memory, or was it also able to be installed on the FASTBUS? C On 4/27/2021 12:36 PM, Michael Thompson via cctech wrote: On 4/24/21 10:28 PM, Noel Chiappa via cctalk wrote: Noel PS: I wonder how many people here have -11/45's? ISTR one other, but they aren't common. The Rhode Island Computer Museum has two. The pair were the interface between fire pull boxes and the 911 dispatch system in Brooklyn, NY. Both have DV11 & DH11 serial controllers. These are capable of the very low baud rates needed to talk to the fire pull boxes. https://www.ricomputermuseum.org/collections-gallery/equipment/dec-pdp-11-45 -- Michael Thompson
Re: DEC PDP-11/45 backplane +5 ECO
> > > On 4/24/21 10:28 PM, Noel Chiappa via cctalk wrote: > > Noel > > > > PS: I wonder how many people here have -11/45's? ISTR one other, but > they aren't > > common. The Rhode Island Computer Museum has two. The pair were the interface between fire pull boxes and the 911 dispatch system in Brooklyn, NY. Both have DV11 & DH11 serial controllers. These are capable of the very low baud rates needed to talk to the fire pull boxes. https://www.ricomputermuseum.org/collections-gallery/equipment/dec-pdp-11-45 -- Michael Thompson
Re: DEC PDP-11/45 backplane +5 ECO
On Sat, Apr 24, 2021 at 9:28 PM Noel Chiappa via cctalk < cctalk@classiccmp.org> wrote: > I had a look at my /45 (a later KB11-D - although I think the backplanes > for > the -A and -D are identical), > I did not think they used the same backplane, but 11/45 maintenance manual (EK-11045-MM-007) confirms that they are. Tables 1-2 for the KB11-A and table 1-3 for the KB11-D confirm that the backplane for both is the 70-08871. It's possible that the KB11-D requires a higher rev of the backplane than the minimum for a KB11-A. That's the case for the 11/70. The KB11-B (original 11/70) and KB11-C (later 11/70) have essentially the same changes as from the KB11-A to KB11-D, and the 11/70 maintenance manual (EK-11070-MM says that both use the 70-11051 backplane, but that for a KB11-C, the backplane must be revision D or later. It sure would be nice to get backplane wirelists for all four (KB11-A, -B, -C, and -D). Also, I'm looking for a Field Maintenance Print Set for the RH70.
RE: DEC PDP-11/45 backplane +5 ECO
> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Fritz
Mueller via cctalk
> Sent: Monday, April 26, 2021 2:27 AM
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: DEC PDP-11/45 backplane +5 ECO
>
>
> > On Apr 24, 2021, at 7:02 PM, Josh Dersch wrote:
> > If you have notes on re-creating the harness, let me know.
>
> Hi Josh,
>
> A few pointers -- I think I left some of these in a comment on one of your
fb posts,
> but will repeat here in case others may find it useful:
Thank you for not hiding your experience on Facebook!
> * Sticking with the original wire color code also makes it a lot easier
not to get lost
> and later to double check and troubleshoot your work. I used MTW
("Machine Tool Wire"),
> which is available from wirebarn.com at 14 and 18 AWG in most of the
necessary colors
> and in 25 and 100 foot lengths (I think the 18 AWG purple I had to find
separately on eBay,
> but I have lots of leftover of that and will gladly send you some.)
>
> --FritzM.
And thank you for the pointer to Wirebarn. Much better stock than at Home
Depot :->.
https://www.wirebarn.com/14-AWG-MTW-MACHINE-TOOL-HOOKUP-WIRE_c_23.html
https://www.wirebarn.com/18-AWG-MTW-MACHINE-TOOL-HOOKUP-WIRE_c_25.html
Those assortments are great. Also the single color in various lengths:
https://www.wirebarn.com/14-Gage-Machine-Tool-Wire-MTW_c_111.html
https://www.wirebarn.com/18-Gage-Machine-Tool-Wire-MTW_c_84.html
-
paul
Re: DEC PDP-11/45 backplane +5 ECO
> On Apr 24, 2021, at 7:02 PM, Josh Dersch wrote:
> If you have notes on re-creating the harness, let me know.
Hi Josh,
A few pointers -- I think I left some of these in a comment on one of your fb
posts, but will repeat here in case others may find it useful:
* The wire list in the commonly available Jun74 11/45 engineering drawing set
is actually for the power harness, and not for the backplane. It includes wire
run lengths in inches, which is quite handy. I believe it is for the newer
harness, but there is much overlap.
* The old and new harnesses are also schematically illustrated on four pages of
the drawing set marked "power systems configuration". These drawings are
complete and quite good.
* Drawings for the power distribution board for the older wiring style
(vertical at the back of the cabinet) are hidden in the Jun74 11/*40*
engineering drawings (upper right of sheet BA11-F0).
* What I did was use the wire list lengths as a guide, cutting each run to
length plus a little extra. I then started with the H742s on the bench, at the
regulator and power monitor mate-n-loks. Then put the H742s in the rack with
the CPU cabinet, and worked my up and over the and then down along the along
the backplane toward the console, bundling and trimming to length as I went.
* A good ratchet lock crimp tool makes a big difference here. You want one
with a die that can handle 14 AWG, and on which will crimp both the electrical
and strain-relief parts of the pins in one go.
* Sticking with the original wire color code also makes it a lot easier not to
get lost and later to double check and troubleshoot your work. I used MTW
("Machine Tool Wire"), which is available from wirebarn.com at 14 and 18 AWG in
most of the necessary colors and in 25 and 100 foot lengths (I think the 18 AWG
purple I had to find separately on eBay, but I have lots of leftover of that
and will gladly send you some.)
* I skipped wiring for most of the regulators in the bottom H742 (I have
regulator F there, but none of H, J, K, or L are populated) because I don't
have any core or fastbus memory in my system. I figure I can add this later if
I ever do find myself with either of these.
Good luck!
--FritzM.
Re: DEC PDP-11/45 backplane +5 ECO
On 4/25/21 12:08 PM, Tom Uban via cctech wrote: On 4/24/21 10:28 PM, Noel Chiappa via cctalk wrote: > From: Fritz Mueller > could I ask that you take some closeups around the Mate-n-Locks along > the top? I'd be very interested to see the board traces and the details > of the red bus wiring there. I had a look at my /45 (a later KB11-D - although I think the backplanes for the -A and -D are identical), and it seems to have heavy red wires attached to the upper row of Mate-n-Lok's that look just like those on Josh's. I'd really want to take pictures of mine (I don't want to take the backplane out - too much work - but I can get decent images with it in, I think) so I can compare them directly, though, not depend on visual memory. Noel PS: I wonder how many people here have -11/45's? ISTR one other, but they aren't common. I have an 11/45. I can also take pics if it would help. --tom I used to have 4 of them. Gave them to people who were trying to set up museums. Never heard how that went. Miss them as much as I miss my 11/24. I have no UNIBUS PDP's anymore. bill
Re: DEC PDP-11/45 backplane +5 ECO
Very interesting -- thanks for the info, folks! My backplane has none of this wiring. I'd really like to see if the traces also look the same, too, though there is no real rush. Hopefully it will be more convenient for Josh to get some straight-on pictures, since his backplane is already pulled. There is also this ECO: > KB11A-B0008 CODE: DF DD: E WL: E SEP-72 [FCO] > > Problem: Small peripheral controller slots in KB11-A panel, slots 26 thru 28, > are not wired to accept some quad module controllers: NPG, PA, PB, LTC, ACLO, > DCLO and +15V are missing. Correction: Revise wiring to include signals > listed above. ...which I have previously verified is *not* implemented on my backplane. I first noticed this because a DL11 in slots SPC slots 26-28 malfunctioned with incorrect signaling levels (because no +15V), but worked just fine if moved over to a backplane expansion. The fact that my backplane is not wired to support trap to 114 on parity err (machine halts instead) has been previously discussed here. Serial number 152 on this one -- seems an early bird indeed.
Re: DEC PDP-11/45 backplane +5 ECO
> I had a look at my /45 ... and it seems to ... look just like those on > Josh's. I'd really want to take pictures of mine .. so I can compare > them directly, though, not depend on visual memory. Yeah, mine (a late /55, actually) has the _exact_ same wires at Josh's. So that's probably the final ECO level. Image here: http://ana-3.lcs.mit.edu/~jnc/tech/pdp11/jpg/1145CPUBackPlane.jpg if you're interested. (Not a great image, but OK; I can try for a better one if there's a need.) > From: Henk Gooijen > Most of the CPU boards in the 11/55 are the same as the ones in the > 11/45 The -11/45, /50 and /55 are all the same CPU (KB11-A or -D), so the same backplane/everything, but differ only if they were sold pre-configured with the MS11 Fastbus memory. And of course some /45's (especially those sold before the introduction of the /50 and /55 as sales options - I have a /45 price list from Sep, 1972 which lists the /45 and /50 but not the /55; and one from Jan, '73 which only lists the /45 :-) were upgraded (possibly after sale, after the /50 and /55 appeared) with MS11 - or possibly some /50's and /55's had the MS11 removed at some point. So the number doesn't mean anything; one has to look at the boards. Noel
Re: DEC PDP-11/45 backplane +5 ECO
I do. An early one from Stanford. Sent from my iPhone > On Apr 24, 2021, at 11:28 PM, Noel Chiappa via cctalk > wrote: > > >> >> From: Fritz Mueller > >> could I ask that you take some closeups around the Mate-n-Locks along >> the top? I'd be very interested to see the board traces and the details >> of the red bus wiring there. > > I had a look at my /45 (a later KB11-D - although I think the backplanes for > the -A and -D are identical), and it seems to have heavy red wires attached > to the upper row of Mate-n-Lok's that look just like those on Josh's. I'd > really want to take pictures of mine (I don't want to take the backplane out > - too much work - but I can get decent images with it in, I think) so I > can compare them directly, though, not depend on visual memory. > >Noel > > PS: I wonder how many people here have -11/45's? ISTR one other, but they > aren't > common.
RE: DEC PDP-11/45 backplane +5 ECO
Van: Noel Chiappa via cctalk<mailto:cctalk@classiccmp.org> Verzonden: zondag 25 april 2021 05:28 Aan: cctalk@classiccmp.org<mailto:cctalk@classiccmp.org> CC: j...@mercury.lcs.mit.edu<mailto:j...@mercury.lcs.mit.edu> Onderwerp: Re: DEC PDP-11/45 backplane +5 ECO PS: I wonder how many people here have -11/45's? ISTR one other, but they aren't common. I have one 11/45, and one 11/55. Most of the CPU boards in the 11/55 are the same as the ones in the 11/45, but I have the M8120 and 4 M8121 boards (32kW bipolar RAM). It is a bit weird, but in the 11/55 are also two G114 boards (4kW MOS RAM), IIRC. Both will need a thorough inspection before powering up! Henk, PA8PDP
Re: DEC PDP-11/45 backplane +5 ECO
On 4/24/21 10:28 PM, Noel Chiappa via cctalk wrote: > > From: Fritz Mueller > > > could I ask that you take some closeups around the Mate-n-Locks along > > the top? I'd be very interested to see the board traces and the details > > of the red bus wiring there. > > I had a look at my /45 (a later KB11-D - although I think the backplanes for > the -A and -D are identical), and it seems to have heavy red wires attached > to the upper row of Mate-n-Lok's that look just like those on Josh's. I'd > really want to take pictures of mine (I don't want to take the backplane out > - too much work - but I can get decent images with it in, I think) so I > can compare them directly, though, not depend on visual memory. > > Noel > > PS: I wonder how many people here have -11/45's? ISTR one other, but they > aren't > common. I have an 11/45. I can also take pics if it would help. --tom
RE: DEC PDP-11/45 backplane +5 ECO
Noel wrote... > PS: I wonder how many people here have -11/45's? ISTR one other, but > they aren't common. Tony replied... I do. -- I have a dual bay 11/45 with RL02, RX02, BA11 expansion, and an early 3rd party (CSI?) linktape. All restored, tested, and working with spares and docs. In retirement I'm focusing on my 21MX systems, but I will keep one or two pdp-11's. The 11/45 will not be one I keep, it's up for sale and may end up on ebay. Other than the 11/45, most of my non-HP stuff will be given or traded away. J
RE: DEC PDP-11/45 backplane +5 ECO
> -Original Message- > From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Tony Duell > via cctalk > Sent: Saturday, April 24, 2021 11:56 PM > To: Noel Chiappa; General Discussion: On-Topic and Off-Topic Posts > Subject: Re: DEC PDP-11/45 backplane +5 ECO > > > PS: I wonder how many people here have -11/45's? ISTR one other, but they > > aren't > > common. > > I do. > > -tony Do #2; not yet fully restored. Soon(ish) ... Has five red bodge wires that appear to be the same as on Josh's photo. https://onedrive.live.com/?authkey=%21AJkwqfjZ3cw06W8=CC8708A7CAEAF7A6=CC8708A7CAEAF7A6%21597691=CC8708A7CAEAF7A6%21597950=OneUp paul
Re: DEC PDP-11/45 backplane +5 ECO
> PS: I wonder how many people here have -11/45's? ISTR one other, but they > aren't > common. I do. -tony
Re: DEC PDP-11/45 backplane +5 ECO
> From: Fritz Mueller > could I ask that you take some closeups around the Mate-n-Locks along > the top? I'd be very interested to see the board traces and the details > of the red bus wiring there. I had a look at my /45 (a later KB11-D - although I think the backplanes for the -A and -D are identical), and it seems to have heavy red wires attached to the upper row of Mate-n-Lok's that look just like those on Josh's. I'd really want to take pictures of mine (I don't want to take the backplane out - too much work - but I can get decent images with it in, I think) so I can compare them directly, though, not depend on visual memory. Noel PS: I wonder how many people here have -11/45's? ISTR one other, but they aren't common.
Re: DEC PDP-11/45 backplane +5 ECO
On Sat, Apr 24, 2021 at 1:36 PM Fritz Mueller via cctalk < cctalk@classiccmp.org> wrote: > Hi Josh, > > Among the pictures linked from your message about the H742a parts, there > is one picture of you backplane. I have been looking for some time for > information about the following 11/45 ECO: > > > KB11-1 CODE: D May-72 [ECO] > > > > Problem: Etch carrying +5V current from Mate-n-Lock pins to backpanel > pins is not heavy enough to carry required current. Correction: Run 24AWG > wire in parallel with etch on panels which already have Mat-n-Lock assembly > installed. Increase thickness of conductor with solder bead if Mate-n-Lock > assembly not installed. PDP-11/45 system serial number 101 and later. > > The wiring arrangements at the top of your backplane look to be a bit > different from mine, and I believe you may have this ECO implemented. > While you have your backplane out, could I ask that you take some closeups > around the Mate-n-Locks along the top? I'd be very interested to see the > board traces and the details of the red bus wiring there. > For sure. I have it on a shelf in the garage to keep it relatively safe while it's out of the chassis, next time I'm out there I'll take some pictures. > > Pictures of the toasted 11/45 suggest that the original machine had the > older power wiring scheme (distribution panel mounted vertically on back of > cabinet instead of horizontally at top of cabinet, etc.) although your > KB11A serial number badge is >2000, which is curious... Yes, I was looking at the service docs and it does seem to match the earlier wiring scheme. If you have notes on re-creating the harness, let me know. The molex shells actually survived the heat (with a couple of exceptions) so I should be able to reuse them. Looks like I'll just need to order up a ton of wire and pins (and a crimper, probably). I'll get the 15V boards out of the H742's this week. - Josh
