Re: Source for DEC TC01 (and similar) bulbs?

[Josh Dersch via cctalk]

On Mon, Dec 6, 2021 at 7:39 AM Michael Thompson <
michael.99.thomp...@gmail.com> wrote:

>
>
> On Sun, Dec 5, 2021 at 11:46 PM Josh Dersch  wrote:
>
>> I swapped boards around in the datapath for these bits on the TC01 side
>> last night and the problem doesn't move.  On a whim I put my thumb on the
>> tape as it passes over the head and it seems to affect the glitchiness of
>> the data, at times making it appear to go away entirely.  Doesn't appear to
>> be a tape tension problem -- it seems adequate and putting my thumb on the
>> supply reel to increase tension a bit does not have the same effect.  This
>> would seem to point to the TU55 being the issue, and quite possibly the
>> heads.  I haven't had time today to look at the signals coming off the
>> heads but I plan to soon.
>>
>> Thanks for the help!
>> - Josh
>>
>
> I would measure the resistance of the head coils at the relay board
> connector. Hopefully they all measure about the same. Figure 2-2 in the
> maintenance manual shows how the MARK and DATA tracks are wired, and the
> extra connection available for the TIMING track. We found a head on the
> PDP-9 where the +D0 connection was open.
>

Looks like I lucked out.  Testing the head signals at the backplane on the
TU55 revealed that pin BD1 was a flat line at about -0.5V.  Turned out to
be a bad relay on the G851 relay board.  (There was also some gnarly black
gunk on the pins on the head connector which somehow wasn't the
problem...)  I don't have any spare relays, but I swapped a G851 in from my
TU56 and the glitches have gone away.  If anyone has any spare relays for
these, or a G851 lying around, let me know.

The Basic Search diagnostic still isn't finding any blocks on the tape, and
I can tell by the lights on the panel that the LPB register isn't doing
much of anything, so I have some more debugging to do.  But I'm really glad
that the TU55 is OK.  Thanks for the help!

- Josh



>
> --
> Michael Thompson
>

Re: RK11-C indicator panel inlays?

[Fritz Mueller via cctalk]

> 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 
> than the boards themselves. Larger boards will be less than US $20 each, if 
> you get a few copies made.

> On Dec 6, 2021, at 5:52 PM, Will Cooke via cctalk  
> wrote:
> Another good option is jlcpcb.com in China.  They are very similar to PCBWay. 
>  I and others I know have been very pleased with them.

I’ve had good experiences lately with both pcbway and jlpcb.

FTGH: PDP-11 Software Source Book, 3rd Ed

[Toby Thain via cctalk]

Hi,

2 volumes, Applications and System. See:  https://imgur.com/a/ISXGK5N

FTGH for postage from Toronto, Canada

--Toby

Re: RK11-C indicator panel inlays?

[Will Cooke via cctalk]

> On 12/06/2021 6:33 PM Jon Elson via cctalk  wrote:
> 
> 
> 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?
> I've been using PCBway in China. Usually, the DHL shipping
> is more expensive than the boards themselves. Larger boards
> will be less than US $20 each, if you get a few copies made.
> 
> Jon

Another good option is jlcpcb.com in China.  They are very similar to PCBWay.  
I and others I know have been very pleased with them.

Will

Re: RK11-C indicator panel inlays?

[Mike Katz via cctalk]

I am currently using kicad for the stuff from other PDP-8/omnibus 
creators but I intensely dislike the user interface paradigm on kicad.


We use Altium at work and I have been thinking about using that.

On 12/6/2021 6:44 PM, David Bridgham via cctalk wrote:

On 12/6/21 17:45, Mike Katz wrote:

If I may8 ask a question.  I have never had boards made before. How 
do I find a good board house that is reasonable and how do I specify 
the board especially for the PDP-8 Omnibus which should have gold 
fingers on the edge connectors?



I was planning to try PCBWay for my boards. They say they do hard gold 
fingers and they have a board assembly option that looks like it can 
do what I need. I haven't used them before so this will be an 
experiment in that direction as well.


If you're using KiCad for your designs (and if the Omnibus uses the 
standard DEC boards), I have templates for double and quad height  
boards that you're welcome to. Since I haven't yet made boards from 
them, check yourself that they're right before ordering but at least 
they'd be a start.


Dave

Hand tool to remove a difficult (stuck) circuit board

[William Sudbrink via cctalk]

I remember seeing this somewhere.  I have done a fair amount of googling
with no luck.

I'm looking for a hand tool with a plyer like grip at the top of a shaft.
At the bottom of the

shaft there is a "foot" that, when you squeeze the grip, scissors open.  The
idea being

that you slide the foot down between a daughter card and the motherboard it
is stuck in

and when you squeeze the grip, it lifts the card out of the slot.  Anybody
know what this

tool is called and/or where to get one?

 

Thanks,

Bill S.

 



-- 
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

Re: RK11-C indicator panel inlays?

[David Bridgham via cctalk]

On 12/6/21 17:45, Mike Katz wrote:

If I may8 ask a question.  I have never had boards made before. How do 
I find a good board house that is reasonable and how do I specify the 
board especially for the PDP-8 Omnibus which should have gold fingers 
on the edge connectors?



I was planning to try PCBWay for my boards. They say they do hard gold 
fingers and they have a board assembly option that looks like it can do 
what I need. I haven't used them before so this will be an experiment in 
that direction as well.


If you're using KiCad for your designs (and if the Omnibus uses the 
standard DEC boards), I have templates for double and quad height  
boards that you're welcome to. Since I haven't yet made boards from 
them, check yourself that they're right before ordering but at least 
they'd be a start.


Dave

Re: RK11-C indicator panel inlays?

[Mike Katz via cctalk]

Thank you.

On 12/6/2021 6:33 PM, Jon Elson via cctalk wrote:

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?


I've been using PCBway in China.  Usually, the DHL shipping is more 
expensive than the boards themselves. Larger boards will be less than 
US $20 each, if you get a few copies made.


Jon

Re: RK11-C indicator panel inlays?

[Jon Elson via cctalk]

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?


I've been using PCBway in China.  Usually, the DHL shipping 
is more expensive than the boards themselves. Larger boards 
will be less than US $20 each, if you get a few copies made.


Jon

Re: RK11-C indicator panel inlays?

[Guy Sotomayor via cctalk]

I haven't priced anything out yet.  My current project will have 
reasonably large sized board but will be using DIN 41612 style 
connectors (so I don't need edge fingers).  I haven't gone to different 
board vendors yet to see what pricing will be yet (still settling on 
board size and number of layers...right now it looks like it'll be 4 
layers).


On 12/6/21 3:50 PM, Mike Katz via cctalk wrote:
For other boards without gold fingers where would you recommend and 
how expensive for omnibus size boards?


On 12/6/2021 5:07 PM, Guy Sotomayor via cctalk wrote:


On 12/6/21 2:45 PM, Mike Katz via cctalk wrote:



If I may8 ask a question.  I have never had boards made before. How 
do I find a good board house that is reasonable and how do I specify 
the board especially for the PDP-8 Omnibus which should have gold 
fingers on the edge connectors?


Anything the size of an Omnibus board with gold fingers is *not* 
going to be "reasonable" especially if you want "hard gold" (which 
IMHO is the only way to go if you want reasonable life of the boards 
and sockets).


I've used Advanced Circuits for all my boards that needed gold 
fingers (they are *not* cheap...you've been warned).  When you submit 
your Gerber files, you also specify if you have edge fingers and how 
you want them plated.  I have been 100% satisfied with the boards 
that I've received from them.


TTFN - Guy





--
TTFN - Guy

Re: RK11-C indicator panel inlays?

[Mike Katz via cctalk]

For other boards without gold fingers where would you recommend and how 
expensive for omnibus size boards?


On 12/6/2021 5:07 PM, Guy Sotomayor via cctalk wrote:


On 12/6/21 2:45 PM, Mike Katz via cctalk wrote:



If I may8 ask a question.  I have never had boards made before. How 
do I find a good board house that is reasonable and how do I specify 
the board especially for the PDP-8 Omnibus which should have gold 
fingers on the edge connectors?


Anything the size of an Omnibus board with gold fingers is *not* going 
to be "reasonable" especially if you want "hard gold" (which IMHO is 
the only way to go if you want reasonable life of the boards and 
sockets).


I've used Advanced Circuits for all my boards that needed gold fingers 
(they are *not* cheap...you've been warned).  When you submit your 
Gerber files, you also specify if you have edge fingers and how you 
want them plated.  I have been 100% satisfied with the boards that 
I've received from them.


TTFN - Guy

Re: RK11-C indicator panel inlays?

[Guy Sotomayor via cctalk]

On 12/6/21 2:45 PM, Mike Katz via cctalk wrote:



If I may8 ask a question.  I have never had boards made before. How do 
I find a good board house that is reasonable and how do I specify the 
board especially for the PDP-8 Omnibus which should have gold fingers 
on the edge connectors?


Anything the size of an Omnibus board with gold fingers is *not* going 
to be "reasonable" especially if you want "hard gold" (which IMHO is the 
only way to go if you want reasonable life of the boards and sockets).


I've used Advanced Circuits for all my boards that needed gold fingers 
(they are *not* cheap...you've been warned).  When you submit your 
Gerber files, you also specify if you have edge fingers and how you want 
them plated.  I have been 100% satisfied with the boards that I've 
received from them.


TTFN - Guy

Re: RK11-C indicator panel inlays?

[Mike Katz via cctalk]

Ethan,

I completely agree with reducing the strip size.

One of my projects is a redesign of Oscar Vermilion's PiDP-8/I using 
addressable LEDs.  I was thinking of breaking the 88 LEDs into separate 
strands based on function (step counter & Multiplier Quotient [17 LEDs], 
accumulator and link [13 LEDs], Memory Buffer [12 LEDs], Memory Address 
[12 LEDs], Data & Instruction Fields and Program Counter [18 bits], 
Instruction & States [17 :LEDs]).  That would require 6 GPIOs.


I don't know if the PIO can handle 6 separate GPIOs like that but it's 
worth a try.


   Mike

On 12/6/2021 3:05 PM, Ethan Dicks wrote:

On Mon, Dec 6, 2021 at 10:36 AM Mike Katz via cctalk
 wrote:

One dumb suggestion to make it easier to control 144 lamps is to use
addressable LEDs.  You can control them in banks or all in a single
serial line.  If you use a single line you can control all of them with
just 1 GPIO.

Each LED requires 24 bits of data.  That would be 3,456 bits.  The
WS2812B has a 300uS low start indication and 1.25 uS per bit.  That
would mean it would take. 4.62mS to update the all of the LEDs.

If 200Hz isn't fast enough for updates, and you have more GPIOs, you
can implement this as, say, 4 strands and write out nybbles.  There
are cheap video wall that use MCUs with DMA engines and pump out 8
strips at once.


Since these are tri-color LEDs you can control the color and simulate
incandescent lamps

Definitely


Another advantage to the LEDs is once they are set, you don't have to
talk to them again until you need to change something.

Yep.  Self-latching.


I am going to use a Raspberry Pi Pico RP2040 CPU's PIO co-processor to
drive the LEDS from a 432 byte array in memory.  All I do is update
which LEDs I want to change and the PIO DMAs the entire array to the LED
chain once every 10mS (or slower depending on need).

Sounds like a great approach.  I have a couple of Picos but haven't
dug into the PIO engines yet.

I've been working with WS2812B LEDs for a while now and enjoyed
watching the cost per LED plummet from a few years ago.

-ethan

Re: PDP - 11 was RK11-C indicator panel inlays? -

[Mike Katz via cctalk]

i'm interested in the RK05 Replica also.

On 12/6/2021 2:27 PM, ben via cctalk wrote:

On 2021-12-06 8:13 a.m., Henk Gooijen via cctalk wrote:

Van: David Bridgham via cctalk
Verzonden: maandag 6 december 2021 15:52
Aan: General Discussion: On-Topic and Off-Topic 
Posts

Onderwerp: Re: RK11-C indicator panel inlays?

On 12/5/21 4:43 PM, Henk Gooijen via cctalk wrote:

I am definitely interested. Never saw the RK-11C (except once on 
eBay some 15 years ago)!
However, I have *two* DX11 front panels with the 144 lamps & 4 
”paddle” connections boards.
I developed a 100x160 mm (Euro-card size) PCB with a PIC18F252 and 
10 MCP23S17 ICs.
You serially send a command to the PIC and the PIC controls the 
MCP23S17 outputs.
Per command you control 8 lamps. On the PCB is one difficult part: a 
4 position one-slot block

to put the 4 paddle boards in.


Fun.  That's a way to get some more lights into your life.  I like it.


Given you have 144 lamps panel with the RK11-C front, what would you 
do to light up the lamps?



I think the only reason to have an RK11-C inlay is if you have an
RK11-C.  Otherwise I can't see that it makes much sense.

The one other place I might, maybe, possibly see one being used is along
with one of our QSICs or USICs.  I could add an option to drive an
RK11-C inlay if someone really thought that was what they wanted but the
RK11-F inlay that we came up with really is a better match and more
functional (which is why we came up with it) as well as supporting the
RP11 implementation that I'm sure I'll get working any day now (snort).

Dave

If this RK11-C “blinkenlight” panel would also become available in a 
60% scaled format,
I would buy it immediately. It would be an “übercool” addition to the 
PiDP-11/70 and
my 60% scaled (“working”) RK05 drive. I only modified the files 
pdp11_cpu and pdp11_rk05,
and added my own code to handle the 2 switches, 8 indicators and the 
door / disk loading.
see https://www.pdp-11.nl/pidp1170/rk05/rk05startpage.html (at the 
bottom of the page).
I will check whether it could be scaled to 60% using standard 3 mm 
(warm-white) LEDs

(if those exist, else I would probably use yellow-ish).

Henk, PA8PDP



USB yuck, is what comes to mind. Other than that the project looks good.

I just built a prototype front panel, with 5 mm white leds, @ 4.5 ma 
each and they are really bright. You want diffused leds or a filter

because you can see the phosphor when the leds are off. CMOS 20v10's
drive the leds and read the keyboard switches. load switches, the
shift in display data, and read switch data out. Display led data
for bit of time a repeat. 10 inches long and 5 inches high card size.


I have been using 16 meg SD cards (standard size) to emulate RK05
style drives for home brew 20 bit cpu (DE1 ALTERA), but your drives 
would make much more impressive system. 5 2901's are planned for

the cpu card, and the control card has about 12 MSI TTL, 2 512x8 proms
and 4 20v10's. 10 inches x 6 form factor and S-100 bus connectors.

This leads me to believe that a PDP-11 could be built also at 60% scale
using PDP-11 parts or 2901's. I would like to see that, rather than some
PI version.

Ben.
PS: How much would a RK05 replica sell for?

Re: RK11-C indicator panel inlays?

[Mike Katz via cctalk]

One of my zillions of projects is to redesign Oscar Vermilion's PdDP-8/I 
using the Raspberry Pi Pico board and these LEDs.


I would use one core for SIMH (the PDP-8 simulator) and one core for the 
Incandescent Emulation.


Right now I'm too busy finding parts for my real PDP-8/E and getting it 
running.


Think of the addressable LEDs and LEDs with the shift register built in 😄.

When you are ready for a redesign, you might consider it for a cost 
reduction.


If I may8 ask a question.  I have never had boards made before. How do I 
find a good board house that is reasonable and how do I specify the 
board especially for the PDP-8 Omnibus which should have gold fingers on 
the edge connectors?


Thanks and good luck,

  Mike

On 12/6/2021 2:07 PM, David Bridgham via cctalk wrote:

On 12/6/21 10:36 AM, Mike Katz via cctalk wrote:



Each LED requires 24 bits of data.  That would be 3,456 bits.  The
WS2812B has a 300uS low start indication and 1.25 uS per bit.  That
would mean it would take. 4.62mS to update the all of the LEDs.


If I'd known about those when I designed my boards, I might well have
gone that way.  They're surprisingly inexpensive even.

Instead, I ended up using a 16-LED driver chip that basically looks like
a shift-register.  I clock in the 144 bits (just on-off, no fancy
tri-color LEDs I'm afraid), toggle the latch signal, and there it is.
If you want to support more indicator panels, it's just a longer shift
register.  I then added RS422 driver chips for noise immunity and there
I was.

Dave

Re: RK11-C indicator panel inlays?

[Ethan Dicks via cctalk]

On Mon, Dec 6, 2021 at 5:28 PM Paul Koning  wrote:
> Raspberry Pico PIO engines are seriously cool.  I used them to implement 
> DDCMP synchronous line protocol in a small USB device wrapped around one of 
> those devices.  That includes the "integral mode" modulate/clock 
> recovery/demodulate functions.

Ooh!  That's neat.  Sounds like it could also become a nice Bisync or
SDLC serial adapter for IBM protocols (something from _my_ background)

But it should probably get its own thread.  ;-)

-ethan

Re: RK11-C indicator panel inlays?

[Paul Koning via cctalk]

> On Dec 6, 2021, at 4:05 PM, Ethan Dicks via cctalk  
> wrote:
> 
> On Mon, Dec 6, 2021 at 10:36 AM Mike Katz via cctalk
>  wrote:
> 
> Sounds like a great approach.  I have a couple of Picos but haven't
> dug into the PIO engines yet.

Raspberry Pico PIO engines are seriously cool.  I used them to implement DDCMP 
synchronous line protocol in a small USB device wrapped around one of those 
devices.  That includes the "integral mode" modulate/clock recovery/demodulate 
functions.

Something I haven't tried but appears possible: 10 Mb/s Ethernet using the PIO. 
 At least full duplex, and perhaps even half duplex.  Not a whole lot of point 
in that, I suppose.  

paul

Re: RK11-C indicator panel inlays?

[Ethan Dicks via cctalk]

On Mon, Dec 6, 2021 at 10:36 AM Mike Katz via cctalk
 wrote:
> One dumb suggestion to make it easier to control 144 lamps is to use
> addressable LEDs.  You can control them in banks or all in a single
> serial line.  If you use a single line you can control all of them with
> just 1 GPIO.
>
> Each LED requires 24 bits of data.  That would be 3,456 bits.  The
> WS2812B has a 300uS low start indication and 1.25 uS per bit.  That
> would mean it would take. 4.62mS to update the all of the LEDs.

If 200Hz isn't fast enough for updates, and you have more GPIOs, you
can implement this as, say, 4 strands and write out nybbles.  There
are cheap video wall that use MCUs with DMA engines and pump out 8
strips at once.

> Since these are tri-color LEDs you can control the color and simulate
> incandescent lamps

Definitely

> Another advantage to the LEDs is once they are set, you don't have to
> talk to them again until you need to change something.

Yep.  Self-latching.

> I am going to use a Raspberry Pi Pico RP2040 CPU's PIO co-processor to
> drive the LEDS from a 432 byte array in memory.  All I do is update
> which LEDs I want to change and the PIO DMAs the entire array to the LED
> chain once every 10mS (or slower depending on need).

Sounds like a great approach.  I have a couple of Picos but haven't
dug into the PIO engines yet.

I've been working with WS2812B LEDs for a while now and enjoyed
watching the cost per LED plummet from a few years ago.

-ethan

Re: PDP - 11 was RK11-C indicator panel inlays? -

[ben via cctalk]

On 2021-12-06 8:13 a.m., Henk Gooijen via cctalk wrote:

Van: David Bridgham via cctalk
Verzonden: maandag 6 december 2021 15:52
Aan: General Discussion: On-Topic and Off-Topic 
Posts
Onderwerp: Re: RK11-C indicator panel inlays?

On 12/5/21 4:43 PM, Henk Gooijen via cctalk wrote:


I am definitely interested. Never saw the RK-11C (except once on eBay some 15 
years ago)!
However, I have *two* DX11 front panels with the 144 lamps & 4 ”paddle” 
connections boards.
I developed a 100x160 mm (Euro-card size) PCB with a PIC18F252 and 10 MCP23S17 
ICs.
You serially send a command to the PIC and the PIC controls the MCP23S17 
outputs.
Per command you control 8 lamps. On the PCB is one difficult part: a 4 position 
one-slot block
to put the 4 paddle boards in.


Fun.  That's a way to get some more lights into your life.  I like it.



Given you have 144 lamps panel with the RK11-C front, what would you do to 
light up the lamps?



I think the only reason to have an RK11-C inlay is if you have an
RK11-C.  Otherwise I can't see that it makes much sense.

The one other place I might, maybe, possibly see one being used is along
with one of our QSICs or USICs.  I could add an option to drive an
RK11-C inlay if someone really thought that was what they wanted but the
RK11-F inlay that we came up with really is a better match and more
functional (which is why we came up with it) as well as supporting the
RP11 implementation that I'm sure I'll get working any day now (snort).

Dave

If this RK11-C “blinkenlight” panel would also become available in a 60% scaled 
format,
I would buy it immediately. It would be an “übercool” addition to the 
PiDP-11/70 and
my 60% scaled (“working”) RK05 drive. I only modified the files pdp11_cpu and 
pdp11_rk05,
and added my own code to handle the 2 switches, 8 indicators and the door / 
disk loading.
see https://www.pdp-11.nl/pidp1170/rk05/rk05startpage.html (at the bottom of 
the page).
I will check whether it could be scaled to 60% using standard 3 mm (warm-white) 
LEDs
(if those exist, else I would probably use yellow-ish).

Henk, PA8PDP



USB yuck, is what comes to mind. Other than that the project looks good.

I just built a prototype front panel, with 5 mm white leds, @ 4.5 ma 
each and they are really bright. You want diffused leds or a filter

because you can see the phosphor when the leds are off. CMOS 20v10's
drive the leds and read the keyboard switches. load switches, the
shift in display data, and read switch data out. Display led data
for bit of time a repeat. 10 inches long and 5 inches high card size.


I have been using 16 meg SD cards (standard size) to emulate RK05
style drives for home brew 20 bit cpu (DE1 ALTERA), but your drives 
would make much more impressive system. 5 2901's are planned for

the cpu card, and the control card has about 12 MSI TTL, 2 512x8 proms
and 4 20v10's. 10 inches x 6 form factor and S-100 bus connectors.

This leads me to believe that a PDP-11 could be built also at 60% scale
using PDP-11 parts or 2901's. I would like to see that, rather than some
PI version.

Ben.
PS: How much would a RK05 replica sell for?

Re: External SCSI Drives on DEC2000 AXP

[Nigel Johnson Ham via cctalk]

Yes, terminator installed as it was when the box was on a PC, with the
LED lit.

Thanks

Nigel


Nigel Johnson, MSc., MIEEE, MCSE VE3ID/G4AJQ/VA3MCU
Amateur Radio, the origin of the open-source concept!
Skype:  TILBURY2591 nw.john...@ieee.org



On 2021-12-06 1:39 p.m., Craig Ruff via cctech wrote:
> Have you verified that the SCSI bus is terminated properly? A missing or 
> improperly configured terminator can sometimes cause those sort of symptoms.

Re: RK11-C indicator panel inlays?

[David Bridgham via cctalk]

On 12/6/21 10:36 AM, Mike Katz via cctalk wrote:


> Each LED requires 24 bits of data.  That would be 3,456 bits.  The
> WS2812B has a 300uS low start indication and 1.25 uS per bit.  That
> would mean it would take. 4.62mS to update the all of the LEDs.


If I'd known about those when I designed my boards, I might well have
gone that way.  They're surprisingly inexpensive even.

Instead, I ended up using a 16-LED driver chip that basically looks like
a shift-register.  I clock in the 144 bits (just on-off, no fancy
tri-color LEDs I'm afraid), toggle the latch signal, and there it is. 
If you want to support more indicator panels, it's just a longer shift
register.  I then added RS422 driver chips for noise immunity and there
I was.

Dave

Re: Need picture of power supply mounted in 11/40 cabinet

[Gregory Beat via cctalk]

Power Supplies, due to their Weight, are placed at the bottom of Racks (prevent 
tip overs / weight distribution).
https://avitech.com.au/?page_id=366

The PDP-11/70 Maintenance and Installation Manual (EK-11070-MM-002) explains 
that the basic PDP-11/70 system components are located in a double cabinet as 
shown in Figure 1-1 of that manual.
https://i0.wp.com/avitech.com.au/wp-content/uploads/2016/05/major-assemblies-fig-1-1.jpg

greg

> Date: Sat, 4 Dec 2021 19:28:01 -0800
> From: Marc Howard 
> To: "General Discussion: On-Topic Posts Only" 
> Subject: Need picture of power supply mounted in 11/40 cabinet

Re: External SCSI Drives on DEC2000 AXP

[Craig Ruff via cctalk]

Have you verified that the SCSI bus is terminated properly? A missing or 
improperly configured terminator can sometimes cause those sort of symptoms.

Re: RK11-C indicator panel inlays?

[David Bridgham via cctalk]

On 12/6/21 10:13 AM, Henk Gooijen via cctalk wrote:


> If this RK11-C “blinkenlight” panel would also become available in a 60% 
> scaled format,
> I would buy it immediately. It would be an “übercool” addition to the 
> PiDP-11/70 and
> my 60% scaled (“working”) RK05 drive. I only modified the files pdp11_cpu and 
> pdp11_rk05,
> and added my own code to handle the 2 switches, 8 indicators and the door / 
> disk loading.
> see https://www.pdp-11.nl/pidp1170/rk05/rk05startpage.html (at the bottom of 
> the page).
> I will check whether it could be scaled to 60% using standard 3 mm 
> (warm-white) LEDs
> (if those exist, else I would probably use yellow-ish).


I do agree that it would be very cool to add a scaled indicator panel to
your PiDP-11 and scaled RK05.  You'd have to do new scaled circuit
boards to be driven from the RPi and a new scaled bezel and light-shield
as well as the inlay.  It's all possible but I don't think I'll be doing
it.  You are most welcome, though, to the work I've done on any and all
of those pieces if you want to take them and scale them down.

If you watched the little video I posted of my early blinking lights,
you probably noticed how blue those white LEDs were.  I've since
switched to a different LED that looks, at least to my eye, a whole lot
better.  In these pictures you can see a comparison.

http://pdp10.froghouse.org/qsic/new-led.jpg

http://pdp10.froghouse.org/qsic/new-led-2.jpg

Dave

Reproduction DEC 144-lamp indicator panels (was Re: RK11-C indicator panel inlays?)

[Ethan Dicks via cctalk]

On Mon, Dec 6, 2021 at 9:42 AM David Bridgham via cctalk
 wrote:
> The inlays are mostly not done with any tools I have.  I do the graphics
> with Inkscape.  Rod made up the blanks with silk screening.  Then I have
> the white printing done at a printshop I found who has a large, flatbed
> printer that can print white ink.  I do have some ideas about how I
> might try to make up blanks with a laser etcher I have access to but at
> the moment we have an ample supply.

Cool.

> Also, I've experimented with making my own bezels out of PVC board from
> Home Depot using a CNC router.  In the pictures below, the yellowed
> bezels are old DEC bezels while the white ones are ones I made.  I
> figured that if we ever get the QSIC shipping and people want indicator
> panels (I hope they'll want indicator panels), I'd rather not depend on
> them ripping apart old DEC bezels to make this work.

Yes.  I'd rather not demolish my only indicator panel.  I was planning
on demolishing a blank (I have a few short blanks, but most people do
not)

> Anyway, I'd be most happy to have another person with more tools to help
> build bits and pieces of this stuff.  I've noticed that as I gained
> access to different tools, I came up with different ideas about how to
> make things.  I didn't think the laser etcher was all that useful until
> I started using it.

I have a small 40W laser etcher that I essentially haven't used since
I have had access to large-format 80-120W laser cutters.

As for tools, I can rent a 4'x8' Shopbot router at our local
Makerspace that can turn out the light blocking bar or, from your
file, the frame.  We also have a local company (IC3D) that makes
cubic-meter 3D Printers and makes their own filament from pellets,
keeping costs down.  The founders are friends of mine and I've helped
repair sensors on their manufacturing line.  If I had an STL, I could
get a bid on what it would take to 3D print one.  It wouldn't be as
smooth as a machined PVC foam milled one, but it would be strong.
With a little post processing, a 3D Printed frame may give an adequate
look.  Just a possibility.  I haven't worked with PVC foam much but I
understand the principle.

>  Now I want to use it for everything.  Turns out it
> can't quite handle 3/8" Delrin; it just melts it and makes a mess.

That sounds like a power problem.  Normally, Delrin lasers quite
nicely, at least at 80W.  Thick stuff is hard in any printer because
of lenses, beam diffusion, etc.  We sometimes have problems with 1/2"
material of any kind in ours.  I've done some stuff in 2 passes, one
high, one low (refocusing/repositioning Z axis between job runs).  We
also have multiple lenses for different focal points.  One is only
good for etching/surface work, and one is good for cutting 3/8" and
thicker materials.  We usually use the middle one since 99% of what
goes into our laser is 3-6mm stock.

> Speaking of help, if anyone wants to review the QSIC design, I'd welcome
> that.  This is by far the most complex circuit board I've ever designed.

I could take a look at it, I have some background in making Qbus and
Unibus interfaces, but how useful I'd be depends on what kind of
feedback you are looking for.

> Back to indicator panels, here's a picture showing a bit of the
> evolution of my indicator panels...
>
> http://pdp10.froghouse.org/qsic/indicator-panel-stack.jpg
>
> ... The only real thing I'd like to
> change is the gloss.  Somehow, DEC's inlay is as flat as flat can be.

I did notice that.  I have no idea what to recommend.  AFAIK, DEC just
used an acrylic with a specific surface texture.  The only stuff I can
get is like what you have - smooth as window glass.

Cheers,

-ethan

Re: Source for DEC TC01 (and similar) bulbs?

[Michael Thompson via cctalk]

On Sun, Dec 5, 2021 at 11:46 PM Josh Dersch  wrote:

> I swapped boards around in the datapath for these bits on the TC01 side
> last night and the problem doesn't move.  On a whim I put my thumb on the
> tape as it passes over the head and it seems to affect the glitchiness of
> the data, at times making it appear to go away entirely.  Doesn't appear to
> be a tape tension problem -- it seems adequate and putting my thumb on the
> supply reel to increase tension a bit does not have the same effect.  This
> would seem to point to the TU55 being the issue, and quite possibly the
> heads.  I haven't had time today to look at the signals coming off the
> heads but I plan to soon.
>
> Thanks for the help!
> - Josh
>

I would measure the resistance of the head coils at the relay board
connector. Hopefully they all measure about the same. Figure 2-2 in the
maintenance manual shows how the MARK and DATA tracks are wired, and the
extra connection available for the TIMING track. We found a head on the
PDP-9 where the +D0 connection was open.

-- 
Michael Thompson

Re: RK11-C indicator panel inlays?

[Mike Katz via cctalk]

One dumb suggestion to make it easier to control 144 lamps is to use 
addressable LEDs.  You can control them in banks or all in a single 
serial line.  If you use a single line you can control all of them with 
just 1 GPIO.


Each LED requires 24 bits of data.  That would be 3,456 bits.  The 
WS2812B has a 300uS low start indication and 1.25 uS per bit.  That 
would mean it would take. 4.62mS to update the all of the LEDs.


Since these are tri-color LEDs you can control the color and simulate 
incandescent lamps (Simh and the PiDP-8/i do this with LED PWM via an 
x/y matrix).


Another advantage to the LEDs is once they are set, you don't have to 
talk to them again until you need to change something.


I am going to use a Raspberry Pi Pico RP2040 CPU's PIO co-processor to 
drive the LEDS from a 432 byte array in memory.  All I do is update 
which LEDs I want to change and the PIO DMAs the entire array to the LED 
chain once every 10mS (or slower depending on need).


On 12/6/2021 9:13 AM, Henk Gooijen via cctalk wrote:

Van: David Bridgham via cctalk
Verzonden: maandag 6 december 2021 15:52
Aan: General Discussion: On-Topic and Off-Topic 
Posts
Onderwerp: Re: RK11-C indicator panel inlays?

On 12/5/21 4:43 PM, Henk Gooijen via cctalk wrote:


I am definitely interested. Never saw the RK-11C (except once on eBay some 15 
years ago)!
However, I have *two* DX11 front panels with the 144 lamps & 4 ”paddle” 
connections boards.
I developed a 100x160 mm (Euro-card size) PCB with a PIC18F252 and 10 MCP23S17 
ICs.
You serially send a command to the PIC and the PIC controls the MCP23S17 
outputs.
Per command you control 8 lamps. On the PCB is one difficult part: a 4 position 
one-slot block
to put the 4 paddle boards in.

Fun.  That's a way to get some more lights into your life.  I like it.



Given you have 144 lamps panel with the RK11-C front, what would you do to 
light up the lamps?


I think the only reason to have an RK11-C inlay is if you have an
RK11-C.  Otherwise I can't see that it makes much sense.

The one other place I might, maybe, possibly see one being used is along
with one of our QSICs or USICs.  I could add an option to drive an
RK11-C inlay if someone really thought that was what they wanted but the
RK11-F inlay that we came up with really is a better match and more
functional (which is why we came up with it) as well as supporting the
RP11 implementation that I'm sure I'll get working any day now (snort).

Dave

If this RK11-C “blinkenlight” panel would also become available in a 60% scaled 
format,
I would buy it immediately. It would be an “übercool” addition to the 
PiDP-11/70 and
my 60% scaled (“working”) RK05 drive. I only modified the files pdp11_cpu and 
pdp11_rk05,
and added my own code to handle the 2 switches, 8 indicators and the door / 
disk loading.
see https://www.pdp-11.nl/pidp1170/rk05/rk05startpage.html (at the bottom of 
the page).
I will check whether it could be scaled to 60% using standard 3 mm (warm-white) 
LEDs
(if those exist, else I would probably use yellow-ish).

Henk, PA8PDP

RE: RK11-C indicator panel inlays?

[Henk Gooijen via cctalk]

Van: David Bridgham via cctalk
Verzonden: maandag 6 december 2021 15:52
Aan: General Discussion: On-Topic and Off-Topic 
Posts
Onderwerp: Re: RK11-C indicator panel inlays?

On 12/5/21 4:43 PM, Henk Gooijen via cctalk wrote:

> I am definitely interested. Never saw the RK-11C (except once on eBay some 15 
> years ago)!
> However, I have *two* DX11 front panels with the 144 lamps & 4 ”paddle” 
> connections boards.
> I developed a 100x160 mm (Euro-card size) PCB with a PIC18F252 and 10 
> MCP23S17 ICs.
> You serially send a command to the PIC and the PIC controls the MCP23S17 
> outputs.
> Per command you control 8 lamps. On the PCB is one difficult part: a 4 
> position one-slot block
> to put the 4 paddle boards in.

Fun.  That's a way to get some more lights into your life.  I like it.


> Given you have 144 lamps panel with the RK11-C front, what would you do to 
> light up the lamps?


I think the only reason to have an RK11-C inlay is if you have an
RK11-C.  Otherwise I can't see that it makes much sense.

The one other place I might, maybe, possibly see one being used is along
with one of our QSICs or USICs.  I could add an option to drive an
RK11-C inlay if someone really thought that was what they wanted but the
RK11-F inlay that we came up with really is a better match and more
functional (which is why we came up with it) as well as supporting the
RP11 implementation that I'm sure I'll get working any day now (snort).

Dave

If this RK11-C “blinkenlight” panel would also become available in a 60% scaled 
format,
I would buy it immediately. It would be an “übercool” addition to the 
PiDP-11/70 and
my 60% scaled (“working”) RK05 drive. I only modified the files pdp11_cpu and 
pdp11_rk05,
and added my own code to handle the 2 switches, 8 indicators and the door / 
disk loading.
see https://www.pdp-11.nl/pidp1170/rk05/rk05startpage.html (at the bottom of 
the page).
I will check whether it could be scaled to 60% using standard 3 mm (warm-white) 
LEDs
(if those exist, else I would probably use yellow-ish).

Henk, PA8PDP

Re: RK11-C indicator panel inlays?

[David Bridgham via cctalk]

On 12/5/21 4:43 PM, Henk Gooijen via cctalk wrote:

> I am definitely interested. Never saw the RK-11C (except once on eBay some 15 
> years ago)!
> However, I have *two* DX11 front panels with the 144 lamps & 4 ”paddle” 
> connections boards.
> I developed a 100x160 mm (Euro-card size) PCB with a PIC18F252 and 10 
> MCP23S17 ICs.
> You serially send a command to the PIC and the PIC controls the MCP23S17 
> outputs.
> Per command you control 8 lamps. On the PCB is one difficult part: a 4 
> position one-slot block
> to put the 4 paddle boards in.

Fun.  That's a way to get some more lights into your life.  I like it.


> Given you have 144 lamps panel with the RK11-C front, what would you do to 
> light up the lamps?


I think the only reason to have an RK11-C inlay is if you have an
RK11-C.  Otherwise I can't see that it makes much sense.

The one other place I might, maybe, possibly see one being used is along
with one of our QSICs or USICs.  I could add an option to drive an
RK11-C inlay if someone really thought that was what they wanted but the
RK11-F inlay that we came up with really is a better match and more
functional (which is why we came up with it) as well as supporting the
RP11 implementation that I'm sure I'll get working any day now (snort).

Dave

Re: RK11-C indicator panel inlays?

[David Bridgham via cctalk]

On 12/5/21 3:24 PM, Ethan Dicks via cctalk wrote:

> This would be really cool as a debugging tool
> more than just as amazing lights.


A great lead-in to my story.  I was working away on the RK11
implementation in the QSIC and when I felt like taking a break but still
wanted to get something done, I'd work on the indicator panel.  Of
course, the indicator panel ended working before the RK11.  Just having
144 lights that I could assign to any purpose was useful but then came
the day when the RK11 was mostly working.  I loaded up an RK11 exerciser
program that Noel wrote and just sat back to bask in the glow of the
blinking lights.  It was a good feeling.

Then I noticed something that wasn't right.  Even though the exerciser
was working, I saw a pattern in the lights that showed up a bug in my
implementation.  I'd really only implemented the indicator panel because
I thought it was fun but it lead me to a bug to fix right off.

Here's a short video clip of the indicator panel in operation and
showing that bug.  I'll leave this for a day or two (or until I remember
again or someone asks) and then say what it is I saw.  I think anyone
with a reasonable familiarity with the QBUS will be able to pick it out
though I'll say that "Latched Address" is the address "half" of the
data/Address Lines, that is the value of those signals when SYNC is
asserted.

http://pdp10.froghouse.org/qsic/ip-full.mp4


> P.S. - not to derail things, but definitely loop me in on the (future)
> thread for making reproductions.  I have access to some tools that
> might make parts of it easier.


The inlays are mostly not done with any tools I have.  I do the graphics
with Inkscape.  Rod made up the blanks with silk screening.  Then I have
the white printing done at a printshop I found who has a large, flatbed
printer that can print white ink.  I do have some ideas about how I
might try to make up blanks with a laser etcher I have access to but at
the moment we have an ample supply.

Also, I've experimented with making my own bezels out of PVC board from
Home Depot using a CNC router.  In the pictures below, the yellowed
bezels are old DEC bezels while the white ones are ones I made.  I
figured that if we ever get the QSIC shipping and people want indicator
panels (I hope they'll want indicator panels), I'd rather not depend on
them ripping apart old DEC bezels to make this work.

Anyway, I'd be most happy to have another person with more tools to help
build bits and pieces of this stuff.  I've noticed that as I gained
access to different tools, I came up with different ideas about how to
make things.  I didn't think the laser etcher was all that useful until
I started using it.  Now I want to use it for everything.  Turns out it
can't quite handle 3/8" Delrin; it just melts it and makes a mess. 
Speaking of help, if anyone wants to review the QSIC design, I'd welcome
that.  This is by far the most complex circuit board I've ever designed.


Back to indicator panels, here's a picture showing a bit of the
evolution of my indicator panels.  The video above shows it really
early, when I just taped a paper inlay to the circuit boards.  Then the
bottom panel in this picture is taping that paper inlay to an MDF light
shield.  The top panel is using one of Rod's blanks with paper labels
taped to it.  And then the third panel down is a printed inlay like
we're talking about now for the RK11-C.  The second indicator panel is a
TC08 inlay that I borrowed from Noel to use as a model as I worked on
the graphics for our own.

http://pdp10.froghouse.org/qsic/indicator-panel-stack.jpg

Here's a close-up of the TC08 and our printed inlay.  I'm rather pleased
with how it looks, I have to admit.  The only real thing I'd like to
change is the gloss.  Somehow, DEC's inlay is as flat as flat can be. 
There is no glare to it whatsoever while ours are quite glossy.  I've
looked at frosted acrylic and it's a little better though really it just
diffuses the glare, it doesn't eliminate it.  I've also tried some
spray-on frosting which helps a little but it also has a tendency for
its solvents to melt the printing that's already there so that's a bit
fraught.

http://pdp10.froghouse.org/qsic/indicator-panel-printed.jpg

Dave

Re: Women of computing

[Scott Quinn via cctalk]

On Sun, 2021-12-05 at 12:00 -0600, Brie wrote:
> 
> He may as well have just come out and said, ?It triggers me and I
> don?t like having to acknowledge that women exist in the field of
> computer history.?
> 
> ? Brie

Sorry to go off topic, but I have friends and family who are veterans
or otherwise have had horrible experiences. They get triggered. What
this sentence is describing is someone getting mildly annoyed.