LCD TVs and monitors for use with BBCs

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VincentVega
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Re: LCD TVs and monitors for use with BBCs

Postby VincentVega » Sun Oct 28, 2012 5:13 pm

Thank you both, 2.1mm PSU ordered!

iainjh
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Re: LCD TVs and monitors for use with BBCs

Postby iainjh » Tue Nov 06, 2012 1:46 pm

I may have missed an earlier post, but can the bbc b psu provide enough power to power both the 8220 and the computer itself? Plus an internal datacentre?

plan A seems to be fit an 8220, internally to the B. Ideally without an extra psu..

(fyi whats just prompted final action on this is my 'play' 19" TV has only one scart, but then has a non powered scart block attached with a number of systems connected. It's not switched in any way and has just blown up my PCengine! I had the B and PCE connected over RGB scart, and it apparently allowed the PCE to pull current from the scart and has blown (hopefully just) an internal fuse! this seems quite common.. if only I knew..

so options really are to either trade up the 19" TV to one thats got more than one rgb scart or go VGA from the BBC. OR get an external powered scart /upscaler box that switches properly. I dont think the RGB>component is a good use of cash. The bbc escaped unscathed but the pce did not)

anyone please confirm the psu can power all that? thanks :)

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Re: LCD TVs and monitors for use with BBCs

Postby retroclinic » Tue Nov 06, 2012 2:29 pm

Yes, the Beeb PSU is pretty robust. If you're going to power that lot, and a dual external drive, I'd probably suggest completely recapping it, including low ESR ones across all the outputs (rather than just the post choke +5v), and fit a BU208A switching transistor. You might also want to fit a fan on the case, becuase it does tend to cook in there, the ventilation is a lot better on a Master.

The DC uses very little current if using a USB flash drive, but obviously more if you put a USB powered Hard Drive on it.

Mark.
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iainjh
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Re: LCD TVs and monitors for use with BBCs

Postby iainjh » Tue Nov 06, 2012 4:08 pm

thanks mark. the floppy I have for that one is externally powered - and the dc is only with CF. thanks for the info.

now what to do re the scart(s)...got to decide, dammit :)

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1024MAK
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Re: LCD TVs and monitors for use with BBCs

Postby 1024MAK » Wed Nov 07, 2012 12:28 am

iainjh wrote:I may have missed an earlier post, but can the bbc b psu provide enough power to power both the 8220 and the computer itself? Plus an internal datacentre?
If the Beeb PSU is serviced like Mark says in the above post, and your floppy drives are externally powered, yes.
A while ago I posted the current used by a GBS-8200 V4.0 converter here. In that post I recommended to use a separate PSU for the GBS-8200 V4.0 converter. It should work with the +5V from the Beeb, but +5V power lines in computers can be noisy. I have only tested my GBS-8200 V4.0 converter with a separate PSU.
iainjh wrote:(fyi whats just prompted final action on this is my 'play' 19" TV has only one scart, but then has a non powered scart block attached with a number of systems connected. It's not switched in any way and has just blown up my PCengine! I had the B and PCE connected over RGB scart, and it apparently allowed the PCE to pull current from the scart and has blown (hopefully just) an internal fuse! this seems quite common..
Internal fuse in the SCART block or the PCengine? Good luck with that, a lot of modern stuff either has no user replaceable fuse, or they use soldered in fusible resistors.
I'm surprised a SCART "block" took out your PCengine :shock:
By SCART "block" what do you mean?
A manually switched type? A electronically switched type that has no PSU so steals power from the attached devices? Or something else?

Mark
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Re: LCD TVs and monitors for use with BBCs

Postby iainjh » Wed Nov 07, 2012 9:32 am

an unswitched block, with 5 input scart sockets all connected to one scart plug out. Apparently the pcengine does have one soldered internal fuse so i have to hope it'll live again. Slim chance but one has to hope.

seems to be a common issue - for instance half way down this thread quote: "which don't isolate the SCART sockets from each other. This can lead to voltage from one system leaking into another, in one instance enough to turn on my SNES without it even being plugged into the wall. .. but it's not exactly an ideal thing to do to your vintage consoles."

http://shmups.system11.org/viewtopic.php?f=6&t=38793&sid=36b7f550a69185228af501306bc4f239

I picked this block up 15 years ago in germany, at the time it was 'leading edge' etc but clearly I've got lucky, up til now. It's fine and will remain fine for taking s-video over adaptor blocks etc, but rgb or fully wired scarts... too risky, as the pce will attend. I dont know whether it pulled the current from the TV scart socket or from on the bbc when that was on, but either way the pce died.

ta for info on the psu. I'l try it, if it get the sparkles etc effects then I will first look at fixing up the psu.

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Re: LCD TVs and monitors for use with BBCs

Postby sweh » Fri Nov 16, 2012 3:29 am

I have a rev4 8200 card. It's powered by a 5V 3A supply. I wired an RGB cable into the socket by the 3 adjustable screws. It works nicely (better picture than I ever got, BITD)... to start with. But after an hour or so then sparklies start to appear. The more data on the screen the more sparklies. So "mode 7" results in maybe one or two random sparklies; filling the screen with random typing causes lots of sparklies.

Does anyone have any idea why sparklies occur and what I can do to stop it?
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danielj
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Re: LCD TVs and monitors for use with BBCs

Postby danielj » Fri Nov 16, 2012 8:42 am

sweh wrote:I have a rev4 8200 card. It's powered by a 5V 3A supply. I wired an RGB cable into the socket by the 3 adjustable screws. It works nicely (better picture than I ever got, BITD)... to start with. But after an hour or so then sparklies start to appear. The more data on the screen the more sparklies. So "mode 7" results in maybe one or two random sparklies; filling the screen with random typing causes lots of sparklies.

Does anyone have any idea why sparklies occur and what I can do to stop it?


Two things seem to do it - firstly image size. Making sure you're nicely extended out over the physical edges of the screen helps, and secondly the RGB pots on the board. Have a fiddle with them and see what you can get to happen!

d.

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sweh
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Re: LCD TVs and monitors for use with BBCs

Postby sweh » Fri Nov 16, 2012 4:18 pm

danielj wrote:Two things seem to do it - firstly image size. Making sure you're nicely extended out over the physical edges of the screen helps, and secondly the RGB pots on the board. Have a fiddle with them and see what you can get to happen!

What confuses me is why it starts off OK. The picture is close to perfect initially. Makes me wonder if heat, somewhere, is causing "thermal noise" (if there's such a thing?). Turning the brightness up on the pots increases the sparkles, turning it down reduces them... but then the image, itself, is too dim.
Rgds
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Re: LCD TVs and monitors for use with BBCs

Postby ptheta » Sun Sep 15, 2013 9:11 pm

I received a V5 board on Friday and got it working following the pin outs given previously. I cut down a cheap VGA cable I had lying around and soldered it to a DIN plug. Got a few sparklies on 1074x768 that I couldn't shift but 640x480 and 800x600 seem promising although I only had a little time to play with it. The other half insisted on doing sociable stuff over the weekend which impacted on my free time. :roll:

What was apparent was just how awful my soldering is. Pretty much of the standard you might expect of a software engineer! I think I'll have to try a couple of simple projects to improve that. Would welcome any suggestions ofvery simple stuff I could build and interface to an Electron with +1 or RPi.

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Re: LCD TVs and monitors for use with BBCs

Postby daveejhitchins » Mon Sep 16, 2013 7:15 am

ptheta wrote:What was apparent was just how awful my soldering is. Pretty much of the standard you might expect of a software engineer! I think I'll have to try a couple of simple projects to improve that. Would welcome any suggestions ofvery simple stuff I could build and interface to an Electron with +1 or RPi.


ptheta: I have kits for: Dual ROM board, ABR board and soon to have available Electron Tube boards. If any of these take your fancy let me know :D

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Re: LCD TVs and monitors for use with BBCs

Postby ptheta » Mon Sep 16, 2013 9:57 am

I will have to get one of those off of you before too long. I think I need to do a little remedial work first. I have the Make electronics book so I think I'll work through the exercises in there and build up to a real board a little later.

Coming back to the 8200, I tried Star Wars and successfully got the loading screen to display but the game itself never appeared. I wondered if this was down to the slightly hit and miss nature of my playing wav files from the PC or if it was down to some fiendish refresh rate trick of the game itself.

I should have disc drive access before long so will have to try it from disc rather than wav file converted from uef.

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danielj
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Re: LCD TVs and monitors for use with BBCs

Postby danielj » Mon Sep 16, 2013 10:08 am

I'd guess the latter, I'm not aware of any tricks with the Elk ULA to get it displaying at different refresh rates or wotnot.


d.

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KarateEd
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Re: LCD TVs and monitors for use with BBCs

Postby KarateEd » Tue Oct 15, 2013 10:37 pm

Hi Semtex,

I'm wondering if you can tell me what power supply you used and what Electronics shop you purchased it at?

Thanks very much,

Ed......:-)

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Re: LCD TVs and monitors for use with BBCs

Postby stevendt » Thu Oct 17, 2013 9:52 am

Greyscale displayed on VGA monitor

Although not to a BBC, I am taking an RGB signal through a HD9800/GBS8200 to a VGA monitor. On one system (using a CGA like TTL RGB signal), it works fine on another, using ~15Khz analogue RGB, I just get greyscale on the VGA monitor.

Am I right in thinking that if I am getting (50?) shades of grey, then the RGB signals must be OK and the problem is on the HD9800/GBS8200 side? I can't see how the analogue RGB signal could "lose" colour.

I have not tried connecting to the VGA monitor directly because of the scan frequency issue. I have also not tried messing with the gain adjustment pots on the HD9800/GBS8200 - would this make a difference?

Any other ideas please?

regards
Dave

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danielj
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Re: LCD TVs and monitors for use with BBCs

Postby danielj » Thu Oct 17, 2013 10:27 am

Try the pots first, then check that you've got the connector wired properly :)

d.

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Re: LCD TVs and monitors for use with BBCs

Postby stevendt » Thu Oct 17, 2013 10:56 am

danielj wrote:Try the pots first, then check that you've got the connector wired properly :)

d.


surely check that you've got the connector wired properly first, then try the pots?

:-)

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danielj
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Re: LCD TVs and monitors for use with BBCs

Postby danielj » Thu Oct 17, 2013 11:32 am

The pots are less faff than the cable :)

d.

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1024MAK
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Re: LCD TVs and monitors for use with BBCs

Postby 1024MAK » Thu Oct 17, 2013 12:17 pm

Does each primary colour (red, green & blue) when toggled between dark and bright produce different grey shades on the display?

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Re: LCD TVs and monitors for use with BBCs

Postby stevendt » Thu Oct 17, 2013 12:37 pm

Hi Mark,

difficult to tell, I can't toggle the primary colours directly at the moment, but changing the screen colour does change the shade of grey. I'll knock up a test program to control the colours and test each in turn - from what I've seen, I expect that they will all produce a different shade of grey

- update - yes, just different shades of grey.

The pots on the card make no difference, I think the video source may be the problem

regards
Dave

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Re: LCD TVs and monitors for use with BBCs

Postby retroclinic » Sat Jan 04, 2014 9:55 pm

Hi.

Just confirming the new LCD Monitor/TV I bought for the testbench is 100% happy with Beebs and Masters in all modes, interlaced and non-interlaced. Model number LG 22MN43D

http://www.currys.co.uk/gbuk/tv-dvd-blu-ray/televisions/small-screen-tvs-up-to-32/lg-22mn43d-22-led-tv-21270376-pdt.html?intcmpid=display~RR~TV%2c+DVD+%26+Blu-ray~21270376

Connected via SCART (LOLCURRYS don't even mention it has one! :roll: ) using one of my cables. Great picture, same high quality as using an Extron DVS204.

It also has legacy VGA as well as HDMI, so is an all round good choice for the compulsive fiddler!

Grab one while you can!

Mark.
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Re: LCD TVs and monitors for use with BBCs

Postby hoglet » Sat Feb 15, 2014 1:31 pm

retroclinic wrote:Just confirming the new LCD Monitor/TV I bought for the testbench is 100% happy with Beebs and Masters in all modes, interlaced and non-interlaced. Model number LG 22MN43D

These are available now at Asda for £99.

I just picked one up in-store (Cribbs Causeway, Bristol).

They are also on Asda Direct:
http://direct.asda.com/LG-22MN43D---LED ... lt,pd.html

Dave

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1024MAK
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Re: LCD TVs and monitors for use with BBCs

Postby 1024MAK » Wed Mar 26, 2014 12:45 pm

See also this topic BBC B on HDMI success! :wink: :D

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Re: LCD TVs and monitors for use with BBCs

Postby IBM portable PC » Mon Jul 31, 2017 11:21 pm

Necroposting I know, however the Extron 204 and 304 do not appear to accept TTL level RGB?
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Re: LCD TVs and monitors for use with BBCs

Postby danielj » Tue Aug 01, 2017 10:21 am

No, you need resistors as you would in an RGB-SCART cable.

d.

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Re: LCD TVs and monitors for use with BBCs

Postby EdwardianDuck » Sat Aug 19, 2017 12:57 pm

A Samsung 22" Full HD (model UE22K5000) purchased today seems to work well with my Master via a Retroclinic supplied SCART cable. This TV has a 4:3 mode, single SCART and 2xHDMI. It does not have legacy VGA, which would have been nice, but the choice of TVs below 32" seems limited these days (albeit on the basis of very little actual research).

Whether it gives a perfect picture or is good in comparison with anything else is hard to say as being a BBC neophyte I don't really know what to expect, but it looks OK to me.

Samsung's website does state that using 4:3 mode for prolonged periods is not recommended as this may cause problems with the TV. That's sort of OK for me as I expect most usage to be text based where a 16:9 aspect ratio will be good enough.

£149 from Argos, other retailers claim to sell the same model.

For completeness (this model is 3-4 years old), a Toshiba 32" Full HD (model 32L4353D) also works well, but is too large for me. Also this model requires you to wait about 2 minutes after powering it on while it loads its operating system (yes, really) before you can select SCART, which could get annoying rather quickly.

Jeremy
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1024MAK
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Re: LCD TVs and monitors for use with BBCs

Postby 1024MAK » Sat Aug 19, 2017 4:24 pm

EdwardianDuck wrote:Samsung's website does state that using 4:3 mode for prolonged periods is not recommended as this may cause problems with the TV.

I've never heard that one before :shock:
I do know that some TV manufacturers cite DOG's (Digital On-Screen Graphic) as a problem in instructions and manuals. But most broadcasters ignore complaints even though DOG's are known to cause bad "screen burn" on CRT and plasma sets, and may cause some damage to LCD sets.

Mark
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Re: LCD TVs and monitors for use with BBCs

Postby EdwardianDuck » Sun Aug 20, 2017 7:57 am

I've never seen that comment about a modern TV either (not that I'm an expert). I don't recall anything to that effect in the manual for my (slightly older) Sony Bravia LCD TV which I use in 4:3 mode a lot for DVDs of old television programs.

Samsung said in the manual (http://downloadcenter.samsung.com/content/UM/201607/20160725174701128/ENG_NLDVBEU4K_Web-1001-160725.0.pdf)...

Do not watch in 4:3 format for a long time. Traces of borders displayed on the left, right and centre of the screen may cause image retention (screen burn) which are not covered by the warranty


For some unspecified value of "long".

Jeremy
Master 128 + RetroClinic DataCentre + Internal Pi Zero Coprocessor, MiST

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Re: LCD TVs and monitors for use with BBCs

Postby chinnyhill10 » Sun Aug 20, 2017 9:07 am

1024MAK wrote:
EdwardianDuck wrote:Samsung's website does state that using 4:3 mode for prolonged periods is not recommended as this may cause problems with the TV.

I've never heard that one before :shock:
I do know that some TV manufacturers cite DOG's (Digital On-Screen Graphic) as a problem in instructions and manuals. But most broadcasters ignore complaints even though DOG's are known to cause bad "screen burn" on CRT and plasma sets, and may cause some damage to LCD sets.

Mark


It's just a disclaimer they put in to prevent warranty claims when someone has a screen on 4:3 for a ridiculous amount of time. Normal use won't be an issue.

My Acorn monitor has a tiny amount of burn on it from the RISC OS Taskbar. It's always happened on displays if something is left on the screen long enough.

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Re: LCD TVs and monitors for use with BBCs

Postby Andrewcee » Sat Oct 14, 2017 3:33 pm

Thanks for info. Bought 8820 for £20, old TV at charity shop for £10, cardboard box 8220 packed in for free, and brilliant results. Few little flashing spots only when screen full of text hardly noticeable, else black. Great job!

New Master on left with video board, original B on right running Solidisk 256 board at 4MHz... if only I can work out to post picture!


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