> On Jan 29, 2024, at 9:54 AM, William Sudbrink via cctalk
> wrote:
> ...the anode cap on the leaking CRT had gone rock hard and there was a small
> "streak" on the back of the CRT that looked like the plastic that it was made
> of had released some sort of oil…
Often times dielectric
Hi folks,
I’m working on a vt220 debug/repair and have gotten to the point where I need
to trace firmware execution at boot. I’ve managed to dump the proms (close to
but slightly different from the versions in Lars’ GitHub) and the 8051 internal
rom, and can load and disassemble these with
> On Sep 6, 2023, at 12:48 PM, Paul Koning via cctalk
> wrote:
>
> The weird case of the 11/05 is because the general registers are assigned
> addresses 177700 through 177707 for R0 through PC, so R1 is at 177701 even
> though it's a word wide. On most models those addresses only work from
> On Sep 6, 2023, at 10:08 AM, Paul Koning via cctalk
> wrote:
> "On what model and under what circumstances will the PC increment by 1?"
At least true on a KD11-B when executing code out of the memory-mapped register
file :-)
(I just happen to have been wading through one of these a couple
Hi folks,
I’ve been picking my way through a PDP-8/L restoration lately. I’ve found that
everything in the machine is covered with a uniform layer of dark “soot”
(enough to blacken your hands while working with it) which I would like to
clean up. Perhaps the “soot” is actually from a
> On Dec 21, 2022, at 7:16 PM, Steve Malikoff via cctalk
> wrote:
>
> For a DLV11 EIA serial connection, I am about to wire up a fly lead cable to
> go from an M7940 SLU (no dash version) 40-pin header to a DB25P … I could use
> any colours but I'd really like to use the original colours for
> On Oct 19, 2022, at 6:16 AM, Paul Koning via cctalk
> wrote:
> ...a couple of years ago I wrote an article about the invention of FM radio,
> in Holland in 1919 (no, not by Armstrong in the USA in the late 1920s).
That sounds interesting, Paul — I’m only familiar with the usual
> On Sat, Jul 30, 2022 at 10:23 PM Ali via cctalk wrote:
> So I am wondering if there is a box that provides a telnet CLIENT to a
> serial port device? I.E. a box smart enough that handles the telnet client,
> LAN functions, and terminal emulations internally and then provides a text
> based
> On Feb 26, 2022, at 2:19 AM, Noel Chiappa via cctalk
> wrote:
> So, either (console halt, or a HALT instruction) will cause the identical
> response in the processor; see Section 4.10.3 "Halt Grant Requests": the CPU
> sends HLT GRANT to the console, which returns SACK. As long as SACK is
>
> On Feb 24, 2022, at 8:24 PM, Noel Chiappa via cctalk
> wrote:
> … at first I thought that maybe you were thinking of the M7850 Parity
> Controller (which is
> actually a memory option, not KD11-E/EA specific; more below), but that's a
> dual card.
Yes, I was thinking of the M7850, but I
> On Feb 21, 2022, at 10:29 AM, Fritz Mueller wrote:
> Also, in taking a look this morning at the M9302 schematic around page 70 in
> the commonly available 11/34 engineering drawings set (rev B, Sep 76), there
> appears to be a mistake! The output of the SACK turnaround circuit is
>
>> From: Fritz Mueller
>> I think you are thinking of the M9302, Noel: a far-side terminator card
>> with integrated SACK turnaround?
> On Feb 21, 2022, at 7:19 AM, Noel Chiappa via cctalk
> wrote:
> No; the M8264 Sack Timeout module. What's an M8264, you say? ...
Ah, quite interesting, didn’t
So, having pulled the CRT now , I was surprised to see that the ground braids
seem to be held against the aquadag by only the pressure from a couple foam
blocks! In my unit these aged foams are deformed and brittle. This would
seem a good thing to add to the check list for looking at these…
> On Feb 20, 2022, at 10:27 PM, Fritz Mueller wrote:
> I’ve begun some work on a VT52 ... is there a way to detach the HV anode lead
> at the board side (does the white “cap” come off the lead connector?)
Well, just answered my own question — went back and tried to be a little more
Hi folks,
I’ve begun some work on a VT52, and need to get the power supply board out onto
my bench for some work. For those who have been in here before: is there a way
to detach the HV anode lead at the board side (does the white “cap” come off
the lead connector?) Or is the only option to
> On Feb 19, 2022, at 10:51 AM, Noel Chiappa via cctalk
> wrote:
> The -11/34 (not the /34A) has something unusual for grant timeouts, but I
> forget the details. I'll look it up.
> On Feb 19, 2022, at 12:11 PM, Fritz Mueller wrote:
> I just did an 11/34 restoration last year, so this is fresh
> On Feb 19, 2022, at 10:51 AM, Noel Chiappa via cctalk
> wrote:
> The -11/34 (not the /34A) has something unusual for grant timeouts, but I
> forget the details. I'll look it up.
I just did an 11/34 restoration last year, so this is fresh in mind — I think
you are thinking of the M9302,
> On 12/6/21 5:50 PM, Mike Katz via cctalk wrote:
> For other boards without gold fingers where would you recommend and how
> expensive for omnibus size boards?
> On 12/06/2021 6:33 PM Jon Elson via cctalk wrote:
> I've been using PCBway in China. Usually, the DHL shipping is more expensive
>
> On Dec 5, 2021, at 1:37 AM, Rob Jarratt wrote:
> I don't see the Kunkin unit for sale except for a couple of items on ebay
> from China. I am really reluctant to buy anything at all from China. I
> couldn't find a manufacturer site for them, and I was wondering if there are
> alternatives
> On 12/5/2021 3:37 AM, Rob Jarratt via cctalk wrote:
> Thanks for the tips. The transformer that drives the bricks is a real beast.
> Did you find an alternative more convenient way to power them on the bench?
No, I just used the big transformer, since I needed to bench and disassemble
the
> On Dec 4, 2021, at 3:57 PM, Rob Jarratt via cctalk
> wrote:
> What kind of load tester are you looking to buy? I have an 11/45 which I need
> to test the power supplies on too.
I picked up a Kunkin KP184 this last year, and it does nicely for testing those
brick regulators and the power
> On Nov 30, 2021, at 7:17 PM, Jay Jaeger via cctalk
> wrote:
> The issue is (I think) that the ExpressPCB software can only be used to
> create files to order boards from them
> On Nov 30, 2021, at 4:31 PM, Paul Koning via cctalk
> wrote:
> You're right, they say so in the FAQ. And it
> On Nov 23, 2021, at 3:17 PM, Josh Dersch via cctalk
> wrote:
> I picked up a TC01 in trade (for a TC08) a couple of weeks back and this
> past weekend I got it hooked up and powered up with my PDP-8/I + TU55
> transport. I've been debugging it and have solved a couple of issues but
> the
> I built mine from a layout on Tom Uban’s site:
> http://www.ubanproductions.com/museum.html
> Did you use that directly with ExpressPCB and order from ExpressPCB or did
> you convert to more standard gerbers?
I just went with ExpressPCB for minimal hassle, but you could probably get it
> On 11/30/21 10:06 AM, Noel Chiappa via cctalk wrote:
> From the blog of someone who got a KB11-A working, you'll really need KM11
> cards...
> On Nov 30, 2021, at 10:59 AM, Guy Sotomayor via cctalk
> wrote:
> I do still have KM11 boards and some overlays (I'd have to check to see if I
> have
> On Oct 26, 2021, at 12:21 PM, Nigel Johnson Ham via cctalk
> wrote:
> Does anybody have any sources other than bitsavers and vcf?
Hi Nigel,
I have hardcopy of a 15 or so page loose leaf manual for “MDB PDP-11 LINE
PRINTER CONTROLLER (CENTRONICS INTERFACE)”, and believe I also have the
A fully-populated 18-bit address space on the /34 and /45 is only 128K words,
which seems like a pretty tight fit for a TCP stack with practically sized
buffers?
I had always sorta assumed DELUA/DEUNA were only practically useful for TCP on
extended Unibus machines (/70, /44, /24, etc.) but I
Hi all,
I've been working on a BA11-K PDP-11/34 lately, and wow it sure is a noisy
thing...
On my '11/45, the "Boxer" fans were easily disassembled via a cir-clip, and
could then have their bearings cleaned/relubed (or worst case replaced). Fan
maintenance quieted down the /45 a good bit.
> On Sep 4, 2021, at 10:42 AM, Rob Jarratt via cctalk
> wrote:
> Another query. The foam filter that sits in the front of my 11/24 CPU is
> clearly badly degraded and needs to be replaced. What do people replace this
> kind of stuff with? I guess it mustn't be too fine, this mesh seems quite
> On Aug 25, 2021, at 10:16 AM, Paul Koning via cctalk
> wrote:
> I have near zero PDP-11 Unix experience, but I remember one flavor (BSD 2.11
> ?) which set the top bit in its alleged ASCII output, which of course would
> break any terminal expecting actual 8 bit coding.
I discovered
> On Aug 12, 2021, at 3:31 PM, Glen Slick wrote:
> If I translate the logical
> sector order RX-02 disk image back into a physical sector order disk
> image (dealing with track shifting, sector interleaving, and track to
> track sector skewing) then RT-11 on SIMH is happy with the disk image.
> On Wed, Aug 11, 2021 at 8:57 AM Fritz Mueller via cctalk
> Could anybody spare a clue or some suggestions on how to access the contents
> of:
> http://bitsavers.trailing-edge.com/bits/DEC/pdp11/floppyimages/rx02/BASIC-11_V2.1_RX02.DSK.zip
> On Aug 11, 2021, at 1:12 PM, Glen S
Hi folks,
Could anybody spare a clue or some suggestions on how to access the contents of:
http://bitsavers.trailing-edge.com/bits/DEC/pdp11/floppyimages/rx02/BASIC-11_V2.1_RX02.DSK.zip
under simh? I haven't had any luck mounting the contained BASIC.DSK e.g. on
simh RY under RT-11. Looking
> On May 23, 2021, at 9:14 PM, Marc Howard via cctech
> wrote:
> In my case I'm looking for the weight of an RK05 and full height 19" DEC
> rack.
I have not see these published, but can attest that it is somewhere between 1
25-yr-old-can-load-in-station-wagon and 1
> On May 10, 2021, at 7:14 AM, Joshua Rice via cctalk
> wrote:
> I would assume it would be trivial to do an injection-moulded run of these
> handles...
They might also be ideal for silicone mold / resin cast, for smaller/home
production runs?
> On May 9, 2021, at 11:18 PM, Dennis Boone via cctalk
> wrote:
> Does anyone have a design for printing card handles for QBUS / UNIBUS
> cards? It seems a natural application.
There is an stl file on this page (4th down on the right):
https://so-much-stuff.com/pdp8/cad/3d.php
I had a few
> On May 8, 2021, at 8:19 PM, ste...@malikoff.com wrote:
> The rack for 14 RK05 cartridges was the DEC p/n H980-CC Disk Storage Rack,
> catalog# A-H980-CC.
> ... There were a number of other shelf and rack options ...
Thanks, Steve! I hadn't heard of the H980-* before. It looks like an
Okay, now that my 11/45 is up and running well, I could really make good use of
one of those rack caddiesfor RK05 packs to hold my most commonly used
system packs for different operating systems. Anybody have one they'd be
willing to sell/trade, or at least the DEC part number so I could
Wow, what a project -- super cool, Jay!
> 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!
> http://bitsavers.org/pdf/dec/pdp11/1145/KB11-A_revS_Engineering_Drawings_Dec1973.pdf
Thanks very much, Al!
> 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
> 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:
>
>
>
> 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
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
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
> On Apr 24, 2021, at 11:50 AM, Josh Dersch via cctalk
> wrote:
> There were two H742a supplies in the rack... I hate to see things go to
> waste...
> ...the power supply boards look like they might be usable after a good
> cleaning and testing.
Hi Josh,
I have H742a's running in my '11/45,
> Now that I've thought about it for a bit, I wonder if you can use a
> nut-and-washer in place of the press fit threaded bushing at the bottom (but
> otherwise all the hardware,and insertion directions, will be the same); it
> will be kind of difficult to get the nut in there with the KY11-L
Thanks for the info, Noel.
There seem to be several small oddities with this cabinet (there was also a
puzzle I posted about here a while back, related to securing the power monitor
board; it turned out with that one that this cabinet is missing some internal
mounting tabs that other folks'
> On Apr 19, 2021, at 8:37 AM, Lee Gleason via cctalk
> wrote:
> Does anyone have an actual, physical, assembled, currently working RK05
> drive that could read it in for me?
Hi Lee -- I have a currently working RK05 attached to an (also currently
working) 11/45, and would be willing to
Thanks Paul, Henk! Yup, it sure looks like there was more than one design for
this...
> On Apr 18, 2021, at 7:40 PM, Noel Chiappa wrote:
> There's an intermediate 10" or so high adapter piece (one either side, of
> course) mounted to the KY11-L... on the bottom, a single 1" or so machine
> screw (#8, I think) goes through the vertical tab on the side at the front of
> the
> On Apr 18, 2021, at 4:57 PM, Mark J. Blair via cctalk
> wrote:
> I'm not at home with the machine now, but if I remember (or get reminded in
> the next day or three), I'll try to take some pictures of my PDP-11/34A to
> help you out.
Thanks, Mark. I'll get some pictures of the brackets I
Hi all,
I'm reassembling an PDP-11/34 in a BA11-K chassis right now, and am a little
puzzled by the front mounting brackets (the ones that hold a KY11-L of either
sort on the bottom, and a half trim-panel on the top). In particular, on the
bottom half, the available place for screws to go to
Subject line says it all -- I'm working on a restoration that includes one of
these, and it looks as if it needs some troubleshooting/repair. I didn't see
docs posted at Bitsavers. Anybody have a manual squirreled away?
cheers,
--FritzM.
> On Mar 24, 2021, at 2:39 PM, Kyle Owen via cctalk
> wrote:
> Does anyone have a picture of the "I've been VAXinated" pin? I know I've
> seen this pin before, probably at some VCF event.
https://www.computerhistory.org/collections/catalog/102682110
Timely!
--FritzM.
> On Tue, Feb 16, 2021 at 2:36 AM Fritz Mueller via cctalk
> wrote:
> So you could set up on t4 or t5 of that microinstruction with the KM11...
> On Feb 16, 2021, at 11:08 AM, Josh Dersch wrote:
> I can't, though -- all of this stuff works fine when running slowly :)
Oh
> On Feb 16, 2021, at 1:13 AM, Josh Dersch wrote:
> My money's on t5 going wrong -- an ALU input mux or operation being selected
> incorrectly, possibly. This also somewhat explains why execution doesn't
> trap due to executing a HALT from an odd address -- it isn't actually
> executing
Hi Josh,
In the situation you describe, I guess I would first chip clip '174s for a
slice of both PCA and PBC on the LA, run the troublesome instruction sequence,
and look at the trace. Check that CLKPCA H and CLKPCB H are happening when and
only when expected, and that all the timing there
> On Feb 9, 2021, at 5:24 PM, Noel Chiappa via cctalk
> wrote:
> BTW, your neat hack to do that only works on the RK11-C, and not the RK11-D:
> the latter doesn't implement 'Read/Write-All'.
Yup -- this is one of the lesser-known advantages of the RK11-C over the later
controllers. Another
> On Feb 9, 2021, at 9:27 AM, Noel Chiappa via cctalk
> wrote:
> ... the Unix V6 RK pack formatter ...
> sets _both_ 'Format' and 'Read/Write-All', and _doesn't_ set up the sector
> header words in the memory buffer, arguing that even with 'Read/Write-All' on,
> the hardware is still
Yup, RK11-C, and it seems complete (modulo drive cables and terminators.) I
have one debugged and running in my '11/45, so I know it well.
> On Feb 8, 2021, at 3:16 PM, Ethan Dicks via cctalk
> wrote:
> The ribbon cables are a bit out of place... perhaps they were just
> stuffed into empty
> On Feb 4, 2021, at 9:45 PM, Josh Dersch wrote:
> The 11/70 is now somewhat operable. I can examine and deposit memory, at
> least for a short while -- after the system warms up for 30 seconds or so the
> Load Address switch stops functioning.
Nice!!
One handy test on '45 is to put the
> On Feb 4, 2021, at 1:51 PM, Josh Dersch wrote:
> [RC maintenance clock] Yeah, you'd think... but it doesn't work :). I
> mentioned earlier in this thread that it's stuck in single-step mode. From
> the schematics it looks like the crystal clock needs to be running to clock
> some of the
> On Feb 3, 2021, at 8:07 PM, Josh Dersch wrote:
> Sure enough, TIGB XTAL H was a flat line. Nothing happening at the crystal
> itself either. The crystal's casing was fairly corroded (which is
> interesting, since nothing else on the board is) and after a tiny bit of
> prodding one of
> On Jan 31, 2021, at 8:19 PM, Josh Dersch wrote:
> Well, what's interesting here is that on my system, switch S4 (MAINT STPR)
> steps the processor with switches S1 and S2 set to *any* configuration.
Hmm, would expect to see S2:1 S1:0 step by microinstruction, and S2:1 S1:1 step
by clock
> Yeah. I want to get the fans installed and then go triple-check all the
> power signals and get the voltages dialed in nicely. But then things come
> out on extenders :).
Yup -- I'm surprised how picky my '45 is about +5 undervolt; it really seems
happiest with trimmed up to about 5.1 at
Hi Josh,
ZAP is effectively reset for the micro-architecture, forcing the ucode address
to known/initial value. It has multiple sources throughout the processor,
including tendrils into some of trap handling hardware. (Caveat: my experience
is based off extensive work with the '11/45, but the
>>> There is definitely yet _another_ keying design, with
>>> triangular sawteeth
>
> Molex
Yup. You'll find them on harnesses in your Atari arcade cabinets :-)
> https://gunkies.org/wiki/DEC_power_distribution_connectors#Connectors
Very useful page; thanks Noel!
> I'm not sure why I bothered to write all this stuff up; it was clearly a waste
> of time.
Arguably (?) not, if you consider cctalk to be the "search engine" that links
people there :-)
> On Jan 19, 2021, at 3:11 AM, Paul Birkel wrote:
> Fritz: You are referring to the 5411086 board as seen in the lower picture
> at: http://gunkies.org/wiki/DEC_Power_Line_Monitor ?
Yes, exactly.
> Mine has screws on all four corners to secure it to corresponding tabs in the
> metal frame
Hi all,
I’m reassembling an H765 supply after cleaning and repairs. It has the "newer"
style 15V and power monitoring board (the one with the edge finger connector,
same as used in H7420 supplies.)
The board slides into a slot in a sub-chassis that also houses the power
control circuitry,
This might be a reasonable stand-in for now:
https://www.millsupply.com/knob-fan-speed-grumman-olson-53777.php?p=324629
> On Jan 9, 2021, at 4:25 PM, Fritz Mueller wrote:
>
>
>> On Jan 9, 2021, at 3:54 PM, Bill Degnan wrote:
>> 3d-printable?
>
> It would seem so. I don’t have one to
> On Jan 9, 2021, at 3:54 PM, Bill Degnan wrote:
> 3d-printable?
It would seem so. I don’t have one to measure, though, and I haven’t seen any
3d models online yet. I could probably eyeball it, but anybody have one and
care to measure?
Does the original have a brass bushing?
Hi folks,
I’m working on an 11/34 at the moment, with the programmer’s console, and it is
missing its front panel power control knob. I think it is the same one used on
the 11/04? Anybody have a spare in their parts stock that they’d be willing to
part with?
(I’m also missing the plastic
Hi all,
I’m just starting in on a PDP-11/34 for a friend (happy holidays!) I currently
have the H765 power supply torn down for cleaning, inspection, and testing as a
first step.
While I have the transformer out on the bench, I’m wondering about the line
interference supression caps on the
> On Dec 4, 2020, at 10:41 PM, Josh Dersch via cctalk
> wrote:
> I realize this is unlikely, but I was curious if anyone has 1) any
> parts of the 11/45 power wiring harness... I can build my own wiring
> harness, but if I can save
> myself the trouble, that'd be nice.
Yeah, I had build my
> On Jul 9, 2020, at 5:02 PM, Robert Armstrong via cctech
> wrote:
> I have an 11/04 with an RK11-D. I have a couple of RK05s, but I wanted to
> test the controller before I start working on the drives. The PDP11
> Diagnostic Handbook says that ZRKJ?? "checks only the drive-independent
On 11/22/19 11:16 AM, Chris Zach via cctalk wrote:
https://i.imgur.com/7BwIwas.jpg
Ah man, I'm jealous of your VT52 roll-around stand -- wish I could find
one for my VT52!
--FritzM.
Hi Ethan,
> On Nov 17, 2019, at 11:25 AM, Ethan Dicks wrote:
> The box is kind of fun, and was standard for word processors and the
> MINC-11 but I can understand wanting a rackable system.
Thanks for the info!
I’m all for keeping things intact when possible, so I’d also be happy to do a
Hi Ulrich,
> On Nov 17, 2019, at 3:59 AM, Ulrich Tagge via cctalk
> wrote:
> I'm interested in the RX01 Drive and equipment.
> Where is the stuff located?
Unfortunately, the list in my email was stuff I wish to buy, not sell :-)
Sorry for being unclear!
--FritzM.
Hi Paul,
> I think you mean RX11.
Ah, yes — I typo’d that, thanks!
> Isn't the BC05L-15 folded up in the case? Or did they put a short one to the
> back of the box? I can't remember now.
I’ll have a look to remind myself when I get downstairs later today. IIRC,
everything is brought out to
Hi all,
I recently picked up a “tabletop” RX01 drive for cheaps. So now I’m in the
market for:
- RK11 controller
- cables
- rack ears, rails (how was this done?)
- formatted media
If anybody here might have any of this and like to work out a deal, feel free
to let me know off-list!
> On Nov 13, 2019, at 9:21 AM, Jay Jaeger via cctalk
> wrote:
> Sure. Works for me. There are, in all, likely well over 1000 fiche...
> 3) I have several sets. Which of them would you want to scan?
>
> On 11/13/2019 12:02 AM, Josh Dersch wrote:
>>
>> If you're willing to send them out,
There were only 2 11/45s that I knew of. The first was the “front end”
that sat in front of all of the terminals and allowed connection to the
various 10s (at the time there were 3: 2 KA10s and a KL10), C.MMP and
CM*. The other 11/45 ran the XGP...
They had moved on to a Xerox 9700 and
First off, I've had a couple of follow-ups on these units, so they are
spoken for at this point.
The member with first dibs has also offered to scan the docs and see
that they make their way to Al.
I was wondering if these were c.mmp cast-offs? Guy: I encountered these
in the CMU computer
Okay, I'm trying to beat back the hoard in my basement before the rainy season
starts here in CA:
I have a couple of NMOS static RAM UNIBUS address spaces that I picked up from
CMU sometime back in the mid-'80s once when they were cleaning house. I've
been hauling these around for 30+ years,
> On Aug 18, 2019, at 1:52 PM, Al Kossow via cctalk
> wrote:
>> Rebuilding cans is a common practice now, since they are LONG out of
>> production.
> https://www.nmr.mgh.harvard.edu/~reese/electrolytics/
Thanks, Al. This is definitely plan B, unless somebody here comes through with
a miracle
I'm working my way through a Tektronix 4006 terminal purchased of eBay right
now. First stage is the low voltage power supplies, and I noticed right away
that one of the multi-stage electrolytic filter caps there was running quite
hot (this was with downstream electronics isolated, and a 40
> I don't know if the front console on the early UNIBUS machines works without
> any memory on the UNIBUS - I'm too lazy to check. I have this vague memory
> that
> they do, though.
The front console on the '45 indeed does run just fine with no UNIBUS (or
FASTBUS) memory in the machine. Its is
> I don't think writing SIMH device emulators for things like the DEC Unibus
> D/A and A/D devices, or the DR11-A, would be at all hard.
Yes; I have also thought it would be nice to have something like a DR11-C in
simh, which could be configured to call into a dynamic library containing user
After a little more research on the net tonight: it looks like the keyboard in
the 4006 was pretty much one of Cherry's standard "B70 ASR" models. The key
mechs are known as M7 T-mount, and the caps look like the standard double shot
ones supplied by Cherry in their mid to late 70's catalogs.
> Can you take a picture of the switches?
> Cindy
Some pics of they keyboard assembly, key cap underside, key mechs, and also the
power toggle I'd like to replace, are here:
https://drive.google.com/open?id=1dKBOdhwgpedYpYCKbGxrd3P9jCNwBRs5
> On Jul 25, 2019, at 10:29 AM, Fritz Mueller wrote:
>
> I recently obtained a Tek 4006 from eBay as a repair/restoration project. It
> is missing a few keycaps (both SHIFT keycaps, COPY, LINE FEED, and :/*). In
> addition, one of the key mechanisms has a broken plunger. Last, the little
Hi folks,
I recently obtained a Tek 4006 from eBay as a repair/restoration project. It
is missing a few keycaps (both SHIFT keycaps, COPY, LINE FEED, and :/*). In
addition, one of the key mechanisms has a broken plunger. Last, the little
green paddle line power toggle power switch at the
Hi Adam,
2307 is an LA30-P (the parallel version of the LA30), like the ones restored by
Herb, Mattis, and myself:
http://www.retrotechnology.com/herbs_stuff/decwriter.html
http://www.datormuseum.se/computers/digital-equipment-corporation/pdp-11-04
(scroll down 3/4)
On 5/10/19 6:42 PM, Adam Thornton via cctech wrote:
I have been invited out to the site tomorrow morning to take an inventory of
what’s there (I live near the machines).
I imagine that I may well have a lot of photos that I bring to the list and say
“what is this?”
Standing by to help out!
> On Apr 23, 2019, at 5:34 PM, Charles via cctalk wrote:
>
> This may be a silly question... but how can I transfer a text file from my PC
> into SIMH for PDP-11?
I've found the most convenient way to do this, for a file or two at a time, is
to use the paper tape reader/punch devices.
Hmmm, are these the atex racks seen lurking in the background of that recent
storage space trawl down near Houston?
https://www.ebay.com/itm/Vintage-DEC-PDP-11-34-Minicomputer-With-Kennedy-Tape-Drive-J11-CPU-2-Terminals/123688125244
> On Feb 28, 2019, at 11:43 AM, Phil Budne wrote:
> It's an indicator that the pre-processor needs to be run first.
Ah, okay! So that's a fun bit of V6 apocrypha. Was this gone by V7?
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