In eager anticipation of completed PiDP-11s becoming operational, I am creating this thread for “brag” shots and construction stories - analogous to the thread in the PiDP-8 group. -NO- “mine’s biggier than yours” claims, please - we know they are all the same size. But if you do anything innovative or cute, show us!
1. Oxidation on switches should be removed before soldering. Not all switches had this problem but I wish I had cleaned each one before assembly (no problems so far).
2. Should the LED cover be left on the final product? Pictures and instructions are unclear.
3. When attaching finished PCB to case, tightening some of the screws causes the PCB to flex. Likely that standoffs are not long enough. Suggestions for fix would be helpful.
5. Switch fixer should be used before soldering first switches.
I had a problem with the back panel. Just pushing with my thumbs to break out one of the holes in the back, the board itself split at the ppoint of the edge of the hole I was trying to break out right to the edge. I recommend putting the back panel on a flat surface, on top of a magazine to allow some play, and tapping gently with a drift punch to get them out.
My only comment regarding assembling the kit is to make sure the switch bodies and and LEDs/spacers are tight against the printed circuit board before soldering.
For the HDMI connector I utilized a 'version B' right angle adapter from https://www.bluejeanscable.com.
Here's mine.
Using rubber bands around the switch "fixer" (outer assembly jig) to hold the switch assembly to the PCB is a great idea. Sadly, I do not have "the knack" mechanically, so despite my best efforts, one of the switches ended up noticeably out of alignment. Oh well.
I like to remove the solder flux from finished PCBs. This is a long, thankless task involving lots of Isopropyl Alcohol (not the pharmacy variety, which has water in it; the paint store variety, which is pure) and a soft toothbrush. It works well enough, but probably isn't too good for the future temperature of the planet.
To separate the Pi from the PCB, I used a rectangle of Mylar sheet, held in place with a strip of double-sided tape.
I also made a little Mylar washer to go between the key switch nut and the front panel.
I added a metal washer between the screw/nut combo which attaches the PCB to the standoffs. This bulked it out just enough to prevent the PCB from warping noticeable when the screws are tightened.
On my kit, the LEDs came out just a little above-centre in their windows.
I haven't done anything about the rear panel yet. Judging by the difficulties some have experienced with the power supply cable, I think I will try to get a stand-alone, panel-mounted USB socket (about $12 in Australia) and hand solder the wires from a stripped-off USB cable.
I will probably attach the case to the base board (for stability) after painting the board a nice, metallic grey colour.
All in all, a superb kit, Oscar. Thank you so much for your gargantuan effort in giving us this lovely piece of memorabilia.
to run model train automation software (in addition to simh), thus giving the impression that the model trains are under the control of a 40 year old mini-computer. If only I could run such software under RSX-11M ...
The one on the top shelf is a Computer Automation Alpha LSI/02 or similar. My final year project in 1977 at Uni was to make a student-friendly interface for it that would allow students to plug their projects in to it without risk of damage to its bus. Haven't ever seen one since, but its little orange keys are iconic.
On Wednesday, 17 October 2018 21:03:46 UTC+1, Roger Arrick wrote:
Shelf of glory :)
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This is achieved with a couple of bits of scrap wood for the housing and one of these:
They're available on Ebay and ship from Hong Kong at a pretty reasonable price. You can choose between different end designs, so you could use a full sized SD card if you wished.
I did the same on my PiDP-8, where it's a bit easier to mount by cutting a slot in the wooden case.
Just an idea in case anyone else is interested.
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I also ran across a problem I created that I think others might experience as well. This time I did use a small wire brush wheel on a Dremmel tool to remove any oxide from the switch terminals prior to soldering. Also, I tried to minimize heating of the switches. To more quickly get heat to the switch terminal and PCB trace, I found I was melting a dab of solder on the iron which allowed the heat to conduct more quickly to the terminal and thus heat the switch for a shorter time. However in my rush to minimize heating I made three cold solder joints. These bad solder joints sometimes work and sometimes did not. Small additional pressure on the switch would occasionally improve the connection. One of the bad solder joints was on the white test switch which further gave weird symptoms as all lights would flicker on when I hit the left ad address next to it.
So anyone with odd switch issues may want to add a 1K to 2K in parallel with the row 0 resistor. I used a 1.8K that gave me an effective 650 ohms. Also, as you individually test the switches any that are intermittently not connecting,
Check for cold solder joints. Maybe this is obvious to most of the folks here, but it had me scratching my head a bit.
Best,
Mark
In eager anticipation of completed PiDP-11s becoming operational, I am creating this thread for “brag” shots and construction stories - analogous to the thread in the PiDP-8 group. -NO- “mine’s biggier than yours” claims, please - we know they are all the same size. But if you do anything innovative or cute, show us!
So far just running the default "light show" but I'll be switching to Unix - nostalgia for my first professional software engineering job in 1982, when we had the *source code* (!!!) to AT&T Unix v7m. I spent nights and weekends just reading Unix source code.... Funny that we're still using it, essentially, - and I'm still making a living doing it - via Linux.
-- jdm
Just attached at the top with Scotch tape at the moment, but I will use another velcro to attach the top of the bookend to the inside top of the pidp case.
The tongue of the bookend then just slides under the books behind it, and then there's no way it will accidentally fall over. It's not rock-solid as if the pidp was attached to a PDP-11 in a rack, as the bookend is flexible. So, you still have to hold the pidp when flipping switches, but for me for now that's fine.
I got lucky in that a bookend I had lying around was exactly the right height!
I see what you are talking about. My 60 mm deep wooden frame is exactly the same outer dimension as the back panel
The biggest problem in my design is that rubber feet need to be added because the flange you are suggesting could be cut off protrudes a bit. What are you thinking of cutting the frame with? A laser cut would be ideal if possible. A mechanical cut might need some polishing. I like working with wood because it is easy to belt sand to close tolerance if you make things a tiny bit oversize.
If the cut were clean on the plastic the attachment could be nicely coupled. You might even want a small square groove in the wood to keep things centered.
I just took a closer look at the bezel and you might only want to cut the outer plastic and leave the stem for the screw intact, but the new box frame would need to be thin. If the stem were cut with the outer shell there is not but stem / bolt hole to screw into.
I also like some of the scaled down rack mount ideas that people have.
Thanks again for a wonderful kit. I really want to get the RSX11M+/Simh/Ethernet software issues solved while on Christmas vacation so we can make a good disk image with everything preinstalled and internet connected.
Mark,
On Thursday, December 20, 2018 at 1:12:02 AM UTC+1, Mark Matlock wrote:I see what you are talking about. My 60 mm deep wooden frame is exactly the same outer dimension as the back panelIn that case, better not chop the PiDP case: it angles out at a 3 degree angle. So if you chop off a bit, the dimensions into which your case fit will be slightly too large!
The biggest problem in my design is that rubber feet need to be added because the flange you are suggesting could be cut off protrudes a bit. What are you thinking of cutting the frame with? A laser cut would be ideal if possible. A mechanical cut might need some polishing. I like working with wood because it is easy to belt sand to close tolerance if you make things a tiny bit oversize.Ah, cutting off the bottom bit would be fine for you case of course.
The local carpenter/furniture maker (the one that does the wood base in the kit) told me he could saw off the back of the case neatly, cleanly, precisely. And that any carpenter could do it.But it's untried & untested so far... I'll send you a new case if the experiment fails ;)
If the cut were clean on the plastic the attachment could be nicely coupled. You might even want a small square groove in the wood to keep things centered.Indeed, that would work nicely!I just took a closer look at the bezel and you might only want to cut the outer plastic and leave the stem for the screw intact, but the new box frame would need to be thin. If the stem were cut with the outer shell there is not but stem / bolt hole to screw into.There is, the stem for the bolt hole is through&through, so if you shorten it in line with the rest of the case it will still hold a screw.
I also like some of the scaled down rack mount ideas that people have.Henk Gooijen really needs to make a kit out of his RK05 enclosure!
Thanks again for a wonderful kit. I really want to get the RSX11M+/Simh/Ethernet software issues solved while on Christmas vacation so we can make a good disk image with everything preinstalled and internet connected.Yes, I have been passive on that front... I was not-so-secretly planning to catch Johnny Billquist at our local VCF last month, but he managed to escape ;)
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In eager anticipation of completed PiDP-11s becoming operational, I am creating this thread for “brag” shots and construction stories - analogous to the thread in the PiDP-8 group. -NO- “mine’s biggier than yours” claims, please - we know they are all the same size. But if you do anything innovative or cute, show us!
So, it turns out you actually *can* get the back panel on, with a reasonable complement of connectors, if you're creative. I wound up trimming off the strain reliefs on both the Ethernet and micro USB extensions from Adafruit, and had to go even further and trim off some of the injection molding on the back of the Ethernet extension.