CJE dual VGA output upscaler. Questions.

on-topic Acorn-related news and discussions not covered by the other forums
Zarchos
Posts: 2355
Joined: Sun May 19, 2013 8:19 am
Location: FRANCE

CJE dual VGA output upscaler. Questions.

Postby Zarchos » Sun Apr 09, 2017 8:33 am

Considering the lousy quality of my YT videos, I see this :
http://www.cjemicros.co.uk/micros/indiv ... SCALEARC-D
and wonder if some people here own such a device or equivalent.

I'm in particular interested by this 'dual VGA output' since I could capture the output from the second VGA connector ...

Any thoughts and considerations welcome.

Z.

User avatar
paulv
Posts: 3606
Joined: Tue Jan 25, 2011 6:37 pm
Location: Leicestershire
Contact:

Re: CJE dual VGA output upscaler. Questions.

Postby paulv » Sun Apr 09, 2017 8:45 am

Pretty sure it's an overpriced GBS8220 in a box.

Paul

Zarchos
Posts: 2355
Joined: Sun May 19, 2013 8:19 am
Location: FRANCE

Re: CJE dual VGA output upscaler. Questions.

Postby Zarchos » Sun Apr 09, 2017 9:01 am

paulv wrote:Pretty sure it's an overpriced GBS8220 in a box.

Paul


I thought so too but I didn't know this device had a dual VGA output.
Going to check that now.

What worried me too with buying the GBS8220 is that I don't know how it behaves if there's no RGB output 'presence' signal : most computers or devices output this signal, but not the A3000 (it's why if you want to make a SCART cable to connect to your TV, you'll have to solder a power supply, or at least a battery holder with a battery to send the minimal 3V necessary to switch your TV to 'listen' to the signals).

User avatar
danielj
Posts: 5364
Joined: Thu Oct 02, 2008 4:51 pm
Location: Manchester

Re: CJE dual VGA output upscaler. Questions.

Postby danielj » Sun Apr 09, 2017 9:06 am

I've used an 8200 with an arc. It works fine with just RGB&S connected, but there are slight artefacts around the mouse pointer when it moves. I imagine the 8220 would be the same.

d.

User avatar
paulv
Posts: 3606
Joined: Tue Jan 25, 2011 6:37 pm
Location: Leicestershire
Contact:

Re: CJE dual VGA output upscaler. Questions.

Postby paulv » Sun Apr 09, 2017 9:07 am

You don't need a power supply in a SCART cable for the A3000. That's only for "auto" detection purposes. Most TV's have manual input and aspect ratio selection capabilities.

Paul

Zarchos
Posts: 2355
Joined: Sun May 19, 2013 8:19 am
Location: FRANCE

Re: CJE dual VGA output upscaler. Questions.

Postby Zarchos » Sun Apr 09, 2017 9:09 am

ok thanks.
And yes there is a dual output version.
Interesting.
Will probably buy one.

So there's no special modification to have it work properly with an Archie ?
Very good to know.

Zarchos
Posts: 2355
Joined: Sun May 19, 2013 8:19 am
Location: FRANCE

Re: CJE dual VGA output upscaler. Questions.

Postby Zarchos » Sun Apr 09, 2017 9:12 am

paulv wrote:You don't need a power supply in a SCART cable for the A3000. That's only for "auto" detection purposes. Most TV's have manual input and aspect ratio selection capabilities.

Paul


From my experience (7 TVs here) only 2 work with the pre ARM250 machines.
The expensive ones. (And not my big Sony with retroprojection technology).
All others have a black screen (even if switched to AV mode).
We already had this discussion in the past, Paul.
Maybe in the U.K. your models behave better than here, the country who designed the SCART standard ? :?

User avatar
paulv
Posts: 3606
Joined: Tue Jan 25, 2011 6:37 pm
Location: Leicestershire
Contact:

Re: CJE dual VGA output upscaler. Questions.

Postby paulv » Sun Apr 09, 2017 9:15 am

No, it's plug and play. Which is easier than installing a VIDC Enhancer to get proper refresh rates but you don't get quite as good a display as a VIDC Enhancer because the GBS82xx is effectively sampling and upscaling the signals so you can have jitter and artefacts as Daniel has observed. With a VIDC Enhancer you're just over clocking the original video hardware like Acorn did in the A540, A5000 etc. so there are no jitter or artefact issues, just a pure VGA output direct from the Arc's video output.

Paul

User avatar
paulv
Posts: 3606
Joined: Tue Jan 25, 2011 6:37 pm
Location: Leicestershire
Contact:

Re: CJE dual VGA output upscaler. Questions.

Postby paulv » Sun Apr 09, 2017 9:22 am

It could well be the difference between the TV's in France and the UK. Although I'm not entirely sure these days about support for different standards being built into TV's but in the UK we have PAL, in France you have SECAM which is similar to PAL but not quite the same and sends colour information differently to PAL.

It could be that the TV's you have don't "like" a PAL signal as output from the British machines because they're expecting a SECAM signal.

Do you know if French TV's support both PAL and SECAM? I have no idea on this but it makes sense to me that this could well be an issue for you as I've never had a TV that doesn't support the Beeb or Arc's signal even if I have to manually select the input and aspect ratio.

EDIT: ISTR that feeding a SECAM signal to PAL or PAL signal to SECAM did result in a picture but it was black and white. I can't remember which way round I observed this but believe it was most likely to be SECAM signal to PAL equipment.

EDIT2: I remember now. I was at school. It was a SECAM encoded VHS tape played back on PAL equipment. It results in a black and white picture.

Paul
Last edited by paulv on Sun Apr 09, 2017 9:47 am, edited 2 times in total.

Zarchos
Posts: 2355
Joined: Sun May 19, 2013 8:19 am
Location: FRANCE

Re: CJE dual VGA output upscaler. Questions.

Postby Zarchos » Sun Apr 09, 2017 9:42 am

Well I'd say they support both PAL and SECAM since I can connect an A3000 or old Archie to all my TVs, provided I have a SCART cable with a power supply or battery holder with a battery ...

As far as the VIDC enhancer is concerned : does it change any timing in the A3000 for example ?
The idea behind my initial query is to show the progress with my sprites plotting routines, and of course it has to be the exact same thing than on a standard Archie ... ie I think you've seen my videos (sorry for your eyes :( )

User avatar
paulv
Posts: 3606
Joined: Tue Jan 25, 2011 6:37 pm
Location: Leicestershire
Contact:

Re: CJE dual VGA output upscaler. Questions.

Postby paulv » Sun Apr 09, 2017 9:46 am

A VIDC Enhancer does change the timings of the VIDC yes, in so much as it makes an A3000 the same as an A3010, A3020, A4000 or A5000.

As different Arc's have different standards in this respect, a VIDC Enhancer makes the older ones the same as the later ones so in effect "standardises" the standard. :lol:

Paul

Zarchos
Posts: 2355
Joined: Sun May 19, 2013 8:19 am
Location: FRANCE

Re: CJE dual VGA output upscaler. Questions.

Postby Zarchos » Sun Apr 09, 2017 9:48 am

paulv wrote:A VIDC Enhancer does change the timings of the VIDC yes, in so much as it makes an A3000 the same as an A3010, A3020, A4000 or A5000.

As different Arc's have different standards in this respect, a VIDC Enhancer makes the older ones the same as the later ones so in effect "standardises" the standard. :lol:

Paul


OK what I mean is in terms of available memory bandwith, does it mean an A3000 with a VIDC enhancer will be slower than a non upgraded one ?

User avatar
paulv
Posts: 3606
Joined: Tue Jan 25, 2011 6:37 pm
Location: Leicestershire
Contact:

Re: CJE dual VGA output upscaler. Questions.

Postby paulv » Sun Apr 09, 2017 9:58 am

Zarchos wrote:
paulv wrote:A VIDC Enhancer does change the timings of the VIDC yes, in so much as it makes an A3000 the same as an A3010, A3020, A4000 or A5000.

As different Arc's have different standards in this respect, a VIDC Enhancer makes the older ones the same as the later ones so in effect "standardises" the standard. :lol:

Paul


OK what I mean is in terms of available memory bandwith, does it mean an A3000 with a VIDC enhancer will be slower than a non upgraded one ?


Right, yes, it's a compromise yes. The later Arc's have 12MHZ memory bandwidth so it's not such an issue. With the 8MHz Arc's the VIDC Enhancer increases the refresh rates by 4.7% on the VGA screens so there's a small reduction in memory bandwidth when outputting to a VGA monitor.

Are you writing your demo's to run using MODE 9/12 or equivalent 15kHz screens or are you writing them to run using MODE 27-31?

If you're doing the former, you're better off recording to a DVR with DVD which can take a SCART PAL signal and then ripping the video from the DVD as it will preserve the original timings and you'll get a good quality signal to create the video with.

That's how I did video's like this from my Beeb.

https://youtu.be/ElJmKQpI4tI

Paul

Zarchos
Posts: 2355
Joined: Sun May 19, 2013 8:19 am
Location: FRANCE

Re: CJE dual VGA output upscaler. Questions.

Postby Zarchos » Sun Apr 09, 2017 10:02 am

OK so it's what I thought.

A pity I got rid of my VHS, really.

Today I'd rather buy an upscaler than add an additional old analogue device I'll only ever use once in a while.
Thanks for your link, will watch with interest.

And thanks for your time helping me, I appreciate. Thanks to all contributors.

Xavier.

EDIT : What's the tune used in your vid ?

User avatar
paulv
Posts: 3606
Joined: Tue Jan 25, 2011 6:37 pm
Location: Leicestershire
Contact:

Re: CJE dual VGA output upscaler. Questions.

Postby paulv » Sun Apr 09, 2017 10:09 am

Zarchos wrote:EDIT : What's the tune used in your vid ?


No idea! I just picked some ambient youtube royalty free music that matched the length of the video which didn't offend me too much and was reminiscent of the sort of music they'd play when transmitting "Pages from Ceefax".

Paul

Zarchos
Posts: 2355
Joined: Sun May 19, 2013 8:19 am
Location: FRANCE

Re: CJE dual VGA output upscaler. Questions.

Postby Zarchos » Sun Apr 09, 2017 10:10 am

:D

User avatar
1024MAK
Posts: 6795
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...

Re: CJE dual VGA output upscaler. Questions.

Postby 1024MAK » Mon Apr 10, 2017 2:04 pm

paulv wrote:You don't need a power supply in a SCART cable for the A3000. That's only for "auto" detection purposes. Most TV's have manual input and aspect ratio selection capabilities.

Paul

Alas some of the modern sets appear to lack manual controls :(

Mark
For a "Complete BBC Games Archive" visit www.bbcmicro.co.uk NOW!
BeebWiki‬ - for answers to many questions...

User avatar
1024MAK
Posts: 6795
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...

Re: CJE dual VGA output upscaler. Questions.

Postby 1024MAK » Mon Apr 10, 2017 2:12 pm

paulv wrote:It could well be the difference between the TV's in France and the UK. Although I'm not entirely sure these days about support for different standards being built into TV's but in the UK we have PAL, in France you have SECAM which is similar to PAL but not quite the same and sends colour information differently to PAL.

It could be that the TV's you have don't "like" a PAL signal as output from the British machines because they're expecting a SECAM signal.

Do you know if French TV's support both PAL and SECAM? I have no idea on this but it makes sense to me that this could well be an issue for you as I've never had a TV that doesn't support the Beeb or Arc's signal even if I have to manually select the input and aspect ratio.

EDIT: ISTR that feeding a SECAM signal to PAL or PAL signal to SECAM did result in a picture but it was black and white. I can't remember which way round I observed this but believe it was most likely to be SECAM signal to PAL equipment.

EDIT2: I remember now. I was at school. It was a SECAM encoded VHS tape played back on PAL equipment. It results in a black and white picture.

Paul

With RGB inputs on a SCART socket, there is NO PAL or SECAM signal. PAL and SECAM are colour encoding systems. RGB does not encode the colour signals into a combined composite signal...

A lot of TVs can display a black and white picture if they do not support the colour encoding in the signal (this includes PAL / SECAM and NTSC).

Please don't get confused between the monochrome TV system (625 line, 50Hz and 525 line, 60Hz) and the colour encoding system.

And note that a colour composite signal is a monochrome signal with colour added.

It is possible (and has been done) to use PAL with 525 line, 60Hz transmissions and to use NTSC with 625 line, 50Hz transmissions.

Of course, if you are intending to use s-video or composite video, then the different colour encoding does make a difference. But any composite video signal will be poor due to the limitations of throwing away picture detail and due to the difficulty in the receiver where it is not possible to completely separate the colour information from the luminance information.

Mark
For a "Complete BBC Games Archive" visit www.bbcmicro.co.uk NOW!
BeebWiki‬ - for answers to many questions...


Return to “general”

Who is online

Users browsing this forum: No registered users and 2 guests