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Seeking advice on Electronica 0511

J

jplr

Experienced Member
Joined
Sep 3, 2022
Messages
190
Location
Brittany/France
Hi,

I bought a USSR Electronica/UKNC MC 0511. I was thinking as a first step to power it with a modern PC PSU, and then to try to communicate it with a RS-232 USB interface.
1. I looked at some MS 0511 internet posts that say MC 0511 needs only 5V internally. Yet the Russian version of the RS-232 interface may need + and - 12V isn't?
How to connect the PSU on the MC 0511?

2. If I understand correctly, as this is a "student" MC 0511, it will try to download its monitor from the network when booting. But if the network card is removed it will show a boot menu, which should propose a RT-11 clone.
2.1. Does this menu appear also on the serial terminal?

2.2. Is it that simple? How to remove the network card?

3. What are common problems with this type of device?

Thank you!
 
Try using UKNCBTL emulator to get a hang of this machine first, esp. if you don't have a disk controller -- it's not very usable without one.

Boot menu should always show up, but only on video output, not on serial.
 
This is my YouTube playlist ... haven't gotten back around to it for a while, but have been meaning to. It's a nice machine.

www.youtube.com

ÐлекÑÑоника ÐС 0511 (Elektronika MS 0511)

Videos about this Soviet-era PDP-11 clone based educational computer, also known as the УÐÐЦ (UKNC).
www.youtube.com www.youtube.com

According to my last video (Part 6), I replaced the original 42VAC power supply with 9VDC because the motherboard in mine (Квант) didn't seem to use the 12V supply.


Replaced the 42VAC power supply - it now runs on 9VDC (or higher) via a 2.1mm socket.
I was originally going to use a Mean Well PSU that output +/-12V and +5V but this КВАНТ (Kvant) board doesn't seem to use one of the 12V polarities anyway.
So we're down to just needing 5V ... in that case, we can either supply it directly via a USB charger & USB socket on the machine, or via a DC plug-pack (say 9VDC) and 5V regulator.
No need to muck around with 240VAC, adding a fuse & socket, connecting the earth, etc.
I'm using a PSU5 regulator from www.ezsbc.com ... these are LM323K replacements and are capable of up to 3A.
Now at 9VDC it is using about 1.6A (14W).
Click to expand...
 
And regarding disk, I have made up some of these boards but not yet gotten around to trying them out:

github.com

GitHub - y-salnikov/uknc_sd_fdd: Контроллер дисковода для УКНЦ (МС0511), использующий образы дисков на SD-карте.

Контроллер дисковода для УКНЦ (МС0511), использующий образы дисков на SD-карте. - y-salnikov/uknc_sd_fdd
github.com github.com

 
jplr said:
Thanks, Shattered and Brett. Brett, I can't find how you connect the 0511 video output to a modern monitor in your videos. Did you use an RGB to VGA/HDMI adapter? In this case, could you kindly share the model?
I am aware that some people used MultiSync monitors with a simple adapter, but most monitors are not Multisync.
Was it similar to the one you describe there:
Click to expand...

It's been a while - I had to look back through one of my videos ... it looks like the 0511 uses an IDC-like connector for the video output, and so I've created a ribbon-cable-to-RCA cable to get composite (AV) video output.

Back then I was using a small Eyoyo screen that is normally used for security cameras or caravans, so it's got a bunch of inputs like VGA, composite (AV) and component. Quite handy in the workshop when dealing with multiple different types of old computers.

I've since swapped that screen out for one with VGA & HDMI only, so yes, I'd need to use a composite-to-XXXX converter box. These can be found anywhere - I think I got mine (here in Australia) from Jaycar. Another good (Aussie) source is Cable Chick.

I got fed up with different video standards so bought a bunch of different converter boxes so I could always handle what I needed ... composite-to-VGA, VGA-to-HDMI, HDMI-to-USB, component-to-VGA, etc.

I also use some basic GBS8200 boards for other, mostly Soviet/post-Soviet machines that have RGBS output. There is an open source improvement for these called "GBS Control" ... you can buy already-made units from Aliexpress.

github.com

GitHub - ramapcsx2/gbs-control

Contribute to ramapcsx2/gbs-control development by creating an account on GitHub.
github.com github.com

Brett.
 
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jplr said:
Many thanks, Brett!
Click to expand...
Let me know if you need the pin-out. I didn't have it handy - I usually document it in the video description of my YT videos but seems I didn't, so it should be in a manual somewhere.

Like I said, I should get back and start working on my 0511 again as well - so can dig out the info if you need. Let me know!
 
I think some folks here know how to restore the original color of this plastic cover. I tried water and soap, and also a cream cleaner that is a bit abrasive. This orange color looks like to be in a thin layer of something but maybe I am wrong and it's due to prolonged solar exposition or entirely something else.
What would you use?
 

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Ouch. Cream cleanser is great for general grime but unfortunately that looks more like "retr0brite" territory.

There's a few ways of doing it ... for me, I just pour some bleach into a large plastic tub (say 180L size ... or just large enough to fit the case), fill with some hot water to cover the plastic, put the lid on and then leave outside in the Aussie sun for a few hours. I usually do this on Commodore VIC-20 cases.

I don't think that's the "official" way of retr0briting, but it works for me.

Our problem here is that there is some printed text on the case that will also get bleached. I think it's worth doing some research on YouTube ... "retr0brite" or just "retrobrite" ... to get a broader range of advice, i.e. about how to cover labels & writing that you can remove beforehand.

Maybe ... because it's only one end, you could just have that end submerged in the solution ... but then you may have a difference in colour.

One drastic solution, that I also apply to Commodore VIC-20s, is to just re-spray the whole case a custom colour. That's when the discolouration is too bad, so I'll paint the case a nice blue or black, for example.
 
Thanks Brett for the good advice!

There is not much sun here in Brittany (roughly same climate as the South of England), but I will try 2 days of outdoor exposition before trying something more complex.
I will post results if successful.
 
I let it outside for a week. It rained mostly all the time, but there was enough progress to satisfy me.
Now I want to replace the ~42v PSU. I bought a PSU that is probably a good fit (+5V/10A, +12V/2A, -5V/1A).
But I wanted to check the pinout of the electrical connector before powering the MS0511.
Something is weird. I removed the PSU connector (XP2) from the motherboard. It seems all pins on the PSU side and the motherboard side are shorted. I guess the probability there is at the same time a short circuit on the motherboard and the PSU is low.
A quick visual inspection of the motherboard shows no trace of some short circuit, but I did not look at the solder side.
Any advice?
 
I'll try to dig mine out today. I think my working one is a KVANT model - it only required +5V only so I replaced the 42VAC PSU with a simple 5V regulator ... I could've probably just installed a USB socket and powered it like that!

Looks like I have two machines - this is the video of the 2nd working one that needed only +5V.

Here's a link (exp. 20-Oct-2024) to my Dropbox where I have some info on the machine, including schematics ... but it's for the SEMZ which is +5V.

And some more links I have in my video descriptions ...

More info:
ru.wikipedia.org

Электроника МС 0511 — Википедия

ru.wikipedia.org ru.wikipedia.org

And more info:


But as I said, I'll dig out my machines and see if I can verify the pin out.

Brett.
 
Many thanks for all this info Brett!
I know the PSU connector pinout, as in one of your videos it's written on the PCB of the PSU.
I guess my worry of having shorted pins is unfounded: I used my ohmmeter for a few minutes and that readout was increasing slowly, so I guess I am just charging a huge capacitor!
If I find the courage and overcome the fear of the magic smoke I will attach that MC 0511 to the power supply in a few days.
 
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