Cub Monitor Question

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hiddenevil
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Cub Monitor Question

Post by hiddenevil » Fri Jan 17, 2020 3:53 pm

Hey everyone

Just a quick question. I was reading up on how one can switch a CUB monitor from digital RGB to Analogue RGB via the pins inside the monitor.

Would it be possible do you think, to hook up some sort of switch allow you to flick between modes? I've not tried this yes, but it's something that I really wouldn't mind giving a shot.

If not a switch, would I be right in thinking I will need to make a new monitor cable fitted with inline resistors, similar to a BBC Micro scart cable?

Image

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1024MAK
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Re: Cub Monitor Question

Post by 1024MAK » Fri Jan 17, 2020 5:56 pm

If there are indeed ‘jumper shunts’ / links, then yes, it is possible to add a switch. I recommend a rotary switch because three separate circuits need to be switched. So a three pole type.

A suitable type is a Taiwan Alpha SR2611F030438F5BD Break Before Make Rotary Switch 3 Pole 4 Way. Rapid carry these under order code 79-0222. Other suitable switches may be available from other suppliers.

You will also need a suitable knob for the switch. And suitable connectors and wiring for connection to the PCB pin headers used for the ‘jumper shunts’ / links. These are usually on a 0.1” (2.54mm) spacing.

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Re: Cub Monitor Question

Post by VectorEyes » Fri Jan 17, 2020 6:25 pm

Out of curiousity, what would happen if you fed the monitor with the wrong signal, ie analogue when it was expecting digital or vice versa?

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Re: Cub Monitor Question

Post by 1024MAK » Fri Jan 17, 2020 6:32 pm

If it is expecting a 0.7V analogue level signal and you feed it a 5V digital (TTL) signal, that colour channel will go to maximum intensity (for all three colour channels, that will be bright white). If you leave it like that, it could cause damage.

If it is expecting a TTL level signal and feed it with a 0.7V analogue signal, you will either get a very dim display, or a blank screen.

Mark

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hiddenevil
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Re: Cub Monitor Question

Post by hiddenevil » Fri Jan 17, 2020 7:25 pm

Well I'm certainly game to try and fit a switch.

Would I be right in thinking the alternative is to take my RGB monitor cable apart and fit resistors inline to the red, green, blue? The same way as RGB scart leads?

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1024MAK
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Re: Cub Monitor Question

Post by 1024MAK » Fri Jan 17, 2020 8:01 pm

Yes, if the Cub monitors use a 75Ω resistor to terminate the inputs when configured for analogue input.

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SimonSideburns
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Re: Cub Monitor Question

Post by SimonSideburns » Fri Jan 17, 2020 8:10 pm

hiddenevil wrote:
Fri Jan 17, 2020 3:53 pm
Would it be possible do you think, to hook up some sort of switch allow you to flick between modes? I've not tried this yes, but it's something that I really wouldn't mind giving a shot.
Image
Exactly what I've done with mine. Was a right faff (my soldering skills seem to have completely dried up - no pun intended - as I've got older), or maybe the iron, solder, or something else is different from when I first learned in 1989.

Anyway, it works. I have a Chameleon colour board for my Beeb and fitting the switch made it more flexible so I could use the monitor on multiple machines without having to keep opening it up and messing with jumpers.

I think I found a hole in the rear of the case of the Cub behind the sticker and put the switch there, or maybe I drilled another hole. I can take a picture if it will be of interest.
Just remember kids, Beeb spelled backwards is Beeb!

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hiddenevil
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Re: Cub Monitor Question

Post by hiddenevil » Fri Jan 17, 2020 8:28 pm

Pictures you say? Hell yes please!

Mine also has some pre cut holes hidden behind the sticker.

I'd like to use the monitor with all my old gear AND get done bloody use out of it. It's annoying to see it just sitting on the unit only to come out when I use my Beeb.

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Re: Cub Monitor Question

Post by SimonSideburns » Fri Jan 17, 2020 8:54 pm

The pictures will have to wait until tomorrow as it's a bit dark now and daylight will help, but I used a switch like this one.
Just remember kids, Beeb spelled backwards is Beeb!

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Re: Cub Monitor Question

Post by hiddenevil » Fri Jan 17, 2020 9:15 pm

No problem, do you recall how you hooked the switch up to the pins? I'm reluctant to solder directly to the board, I'm thinking I might use jumper wires like these https://www.ebay.co.uk/itm/40pcs-Dupont ... 1e4525cba3

That way I can remove them should the need arise in the future, say if the monitor ever needs servicing. Which it probably could do with, if I knew anyone who could service it.

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Re: Cub Monitor Question

Post by SimonSideburns » Fri Jan 17, 2020 10:17 pm

I soldered them in, but I wasn't ever really expecting to have to desolder them at some point in the future, except for there being some problem or suchlike.

With some hindsight, I would have used some sort of connectors (similar to the type of things of which there usually are a number that you connect from a PC case to the motherboard inside, and are used to connect up the speaker, power button, reset, etc. and then if at some point I wished to it would have been simpler to remove the modification.

When you compare the two positions for each jumper, you notice one of the pins is connected to a jumper in both cases (the middle one) and effectively for say analogue it's on pins 1 and 2, and for digital it's on pins 2 and 3.

The switch is three pole, double throw. What that means is there are 9 pins.

If I number them like this:

Code: Select all

1-2-3
4-5-6
7-8-9
then pins 1 to 3 could be connected to the red jumper pins, pins 4 to 6 could go to the green jumper pins and pins 7 to 9 could go to say the blue jumper pins.

The way the switch would be connected internally, pin 2, 5 or 8 is the common one (e.g. similar to the middle jumper pin) and the other two would be either analogue or digital (but make sure you are consistent).

So, for red, I would connect switch pin 1 to the analogue side of the red jumper, switch pin 2 to the common (middle) pin of the red jumper and pin 3 to the digital pin of the red jumper, and then make sure to do the same for green and blue.

I hope that helps, and I can try to take pictures of my shoddy wiring if it helps, but my description should be more than enough of a clue (and the switch being quite small, I don't think you'd be able to see much anyway).

WIth regard to the wires and connectors, you might find this sort of thing much easier. Get the three position ones. You'd need three of them (the listing I've shared is for 10) and it would be far simpler chopping off the male connector end and soldering the wires directly to the switch before even opening up the monitor.

You would then only have to open the monitor, fit the switch, then plug in the three connectors into the position of the jumpers.
Just remember kids, Beeb spelled backwards is Beeb!

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Re: Cub Monitor Question

Post by hiddenevil » Sat Jan 18, 2020 12:22 am

I bought the wires, going to order a nice looking 80s switch lol

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hiddenevil
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Re: Cub Monitor Question

Post by hiddenevil » Tue Jan 21, 2020 12:28 pm

Hey guys

I worked on a diagram over the weekend, hoping to start wiring the monitor this week (once the bits have arrived)

https://drive.google.com/file/d/11FRl0P ... sp=sharing

Note, this is of a 3 pole toggle switch, though it has been suggested that i could use a rotary switch.

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Re: Cub Monitor Question

Post by SimonSideburns » Tue Jan 21, 2020 11:05 pm

hiddenevil wrote:
Tue Jan 21, 2020 12:28 pm
Hey guys

I worked on a diagram over the weekend, hoping to start wiring the monitor this week (once the bits have arrived)

https://drive.google.com/file/d/11FRl0P ... sp=sharing

Note, this is of a 3 pole toggle switch, though it has been suggested that i could use a rotary switch.
Looking at your diagram you aren't consistent enough. Within each set of 3 pins you need the central jumper pin connected to the centre of each switch row.

Your middle set of 3 pins has the central pin at the left which means it wouldn't be switching properly.

Hope that makes sense.
Just remember kids, Beeb spelled backwards is Beeb!

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Re: Cub Monitor Question

Post by SimonSideburns » Wed Jan 22, 2020 12:09 am

Hopefully this diagram explains it a whole lot better:
CUB Monitor jumpers to new switch.png
CUB Monitor jumpers to new switch.png (5.7 KiB) Viewed 1560 times
I've grouped each set of three jumper pins into different colours (and I've deliberately not used red, green or blue for the groups). It doesn't really matter which ones are red, green or blue, as long as the three groups are different and easy to see.

Now for each group I've identified which pin is connected for both Analogue and for Digital (following the diagrams you posted) and this is the central pin of each group of three, which I've decided to label as Signal. Then, following the two diagrams I've worked out which pin is Analogue and which is Digital. I've then made that distinction on both the jumper connection block and your new switch.

Having colour coded the switch, and labelled the columns (which I'm hoping is correct), you should be able to follow the wires from their groups of pins on the jumper block to the correct location in the switch.

For example, all jumper pins labelled as signal should line up in the signal column in the switch, and the same for analogue and digital.

When you go back to your sketch, if you check it through, the 'signal' jumper from the middle group of three pins ended up in the wrong place on the switch.
I really do hope that helps.
Just remember kids, Beeb spelled backwards is Beeb!

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hiddenevil
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Re: Cub Monitor Question

Post by hiddenevil » Sat Jan 25, 2020 1:05 am

Thanks for that, I suspected I had overlooked something. Which is why I shared it. Better to have another pair of eyes take a look :D

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Re: Cub Monitor Question

Post by hiddenevil » Wed Jan 29, 2020 7:46 pm

I might be using a rotary switch instead of a toggle switch. Would the wiring be the same?

I've never worked with rotary switches before and thought it better to ask. Instead of just go in blindly and potentially damage the monitor.

:-D

SimonSideburns wrote:
Wed Jan 22, 2020 12:09 am
Hopefully this diagram explains it a whole lot better:

CUB Monitor jumpers to new switch.png

I've grouped each set of three jumper pins into different colours (and I've deliberately not used red, green or blue for the groups). It doesn't really matter which ones are red, green or blue, as long as the three groups are different and easy to see.

Now for each group I've identified which pin is connected for both Analogue and for Digital (following the diagrams you posted) and this is the central pin of each group of three, which I've decided to label as Signal. Then, following the two diagrams I've worked out which pin is Analogue and which is Digital. I've then made that distinction on both the jumper connection block and your new switch.

Having colour coded the switch, and labelled the columns (which I'm hoping is correct), you should be able to follow the wires from their groups of pins on the jumper block to the correct location in the switch.

For example, all jumper pins labelled as signal should line up in the signal column in the switch, and the same for analogue and digital.

When you go back to your sketch, if you check it through, the 'signal' jumper from the middle group of three pins ended up in the wrong place on the switch.
I really do hope that helps.

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Re: Cub Monitor Question

Post by SimonSideburns » Wed Jan 29, 2020 9:25 pm

As long as the switch is triple pole double throw it should be usable.

If you get a data sheet with the switch, or take a picture of the pins on the switch and upload it here, it might be possible to figure out which pins do what.

Failing that, do you have a multi-meter? If so, you could probably figure out which pins connect to others when the switch is in different positions, or we could help you identify which ones go where.

Probably best to take that picture first and we can then decide how to proceed.
Just remember kids, Beeb spelled backwards is Beeb!

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Re: Cub Monitor Question

Post by 1024MAK » Wed Jan 29, 2020 10:48 pm

I can take a photo of the 12 way switch that I have, if that helps.

Mark

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Re: Cub Monitor Question

Post by hiddenevil » Thu Jan 30, 2020 1:01 am

Thanks Mark, I honestly don't think there is such a thing as being to prepared. And having plenty of information will only insure I do I good job and don't cock it up.

I plan on doing the modification tomorrow evening, I'm hoping it will result in a Beeb, C64, Speccy compatible CUB monitor.

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Re: Cub Monitor Question

Post by 1024MAK » Thu Jan 30, 2020 9:49 pm

So I remembered that I have used a similar rotary switch in an audio item some years ago. Here are some photos showing it:
0C74E36F-F0E9-4A5A-8DF6-F15B52D1F9B6.jpeg
E6F8798E-A9E3-4476-921D-BB6471C5932B.jpeg
3CBC6CFE-36B1-4FB7-9BC1-66B02EAE8FB8.jpeg
D0C0D327-818C-4ED4-88CF-47596591F5FD.jpeg
948AF1AE-B1C6-42A8-AFC3-97349E5DE064.jpeg
E5EACA4D-4959-4EE0-B8D7-365D356E8B4C.jpeg
This is a 4 position switch.

Mark

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Re: Cub Monitor Question

Post by 1024MAK » Fri Jan 31, 2020 4:18 pm

16A08184-2B6B-4047-AC79-6AE997A999D9.jpeg
Rotary switch
For a three position switch, the typical wiring is as follows:
The three connection solder tags in the centre are labelled A, B and C.
A is the common pin for the outer ring solder tags numbered 1, 2, 3 and 4.
B is the common pin for the outer ring solder tags numbered 5, 6, 7 and 8.
C is the common pin for the outer ring solder tags numbered 9, 10, 11 and 12.

Here is a picture I found on the web:
Image
This is a four position switch.

The typical wiring is as follows:
The four connection solder tags in the centre are labelled A, B, C and D.
A is the common pin for the outer ring solder tags numbered 1, 2 and 3.
B is the common pin for the outer ring solder tags numbered 4, 5 and 6.
C is the common pin for the outer ring solder tags numbered 7, 8 and 9.
D is the common pin for the outer ring solder tags numbered 10, 11 and 12.

So in the most anti-clockwise position, A is connected to 1, B is connected to 4, C is connected to 7 and D is connected to 10.
Turn the switch clockwise one position, then A is connected to 2, B is connected to 5, C is connected to 8 and D is connected to 11. Hopefully you get the idea.

Mark

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Re: Cub Monitor Question

Post by johnkenyon » Fri Jan 31, 2020 5:26 pm

1024MAK wrote:
Fri Jan 31, 2020 4:18 pm
16A08184-2B6B-4047-AC79-6AE997A999D9.jpeg

For a three position switch, the typical wiring is as follows:
The three connection solder tags in the centre are labelled A, B and C.
A is the common pin for the outer ring solder tags numbered 1, 2, 3 and 4.
B is the common pin for the outer ring solder tags numbered 5, 6, 7 and 8.
C is the common pin for the outer ring solder tags numbered 9, 10, 11 and 12.

Here is a picture I found on the web:
Image
This is a four position switch.

The typical wiring is as follows:
The four connection solder tags in the centre are labelled A, B, C and D.
A is the common pin for the outer ring solder tags numbered 1, 2 and 3.
B is the common pin for the outer ring solder tags numbered 4, 5 and 6.
C is the common pin for the outer ring solder tags numbered 7, 8 and 9.
D is the common pin for the outer ring solder tags numbered 10, 11 and 12.

So in the most anti-clockwise position, A is connected to 1, B is connected to 4, C is connected to 7 and D is connected to 10.
Turn the switch clockwise one position, then A is connected to 2, B is connected to 5, C is connected to 8 and D is connected to 11. Hopefully you get the idea.

Mark
You can also easily modify these rotary switches to reduce the number of positions, by removing the nut on the "front" and lifting the washer which has a small tab which acts as a rotation stop.

If your switch has enough poles but too many positions, undo the nut, lift the washer, rotate it by the required number of positions then drop it back in and secure it.

For example, for an RGB/TTL switch you need a minimum of three poles and two way/positions, but you can only get a "3 pole 4 way/position" or a "4 pole 3way/position" switch.

If the spares bin yields a 4P/3W you can move the end stop by one position and you then have a 4 pole 2 way switch.
Or if you have a 3 pole 4 way switch, move it by two positions to get your 2 way (RGB or TTL) switch.

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Re: Cub Monitor Question

Post by 1024MAK » Fri Jan 31, 2020 5:48 pm

johnkenyon wrote:
Fri Jan 31, 2020 5:26 pm

You can also easily modify these rotary switches to reduce the number of positions, by removing the nut on the "front" and lifting the washer which has a small tab which acts as a rotation stop.
Absolutely yes.

Mark

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Re: Cub Monitor Question

Post by hiddenevil » Sun Feb 02, 2020 7:37 pm

Hi Guys

I sadly didn't get chance to work on the monitor over the weekend, but I'm kind of glad I held off as I just saw the images that were recently posted.

Thanks so much! Thats pretty much armed me with what I need to attack this little addon. I shall post back soon with my progress :D

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Re: Cub Monitor Question

Post by SimonSideburns » Sun Feb 02, 2020 7:42 pm

I was asked in private message to upload a larger version of my diagram.

I couldn't add it to the reply to the pm, so I said I'd upload it here instead. It doesn't look any bigger but will go larger when you click on it.

Here it is:
CUB Monitor jumpers to new switch.png
Hope that helps.
Just remember kids, Beeb spelled backwards is Beeb!

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hiddenevil
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Re: Cub Monitor Question

Post by hiddenevil » Sun Feb 02, 2020 7:47 pm

Many thanks!

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Re: Cub Monitor Question

Post by hiddenevil » Fri Apr 03, 2020 12:57 pm

Well now i'm stuck in doors, i'm finally able to get back to this! So expect an update soon :D

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Re: Cub Monitor Question

Post by SimonSideburns » Fri Apr 03, 2020 10:26 pm

Fingers crossed all goes well.
Just remember kids, Beeb spelled backwards is Beeb!

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Re: Cub Monitor Question

Post by Multiwizard » Sat Apr 04, 2020 6:37 am

Thanks for sorting it out & the pic... :D =D>


Greetings, Wim... :-)

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