Seeing as you have the most expertise amongst us wrt PAL video signals, perhaps you could supply us with the defacto definition and breakdown of it.
That way we could construct a more accurate driver.
@Coley "I now know that if I can get Mike happy with the output then it is commercially viable!" Will purchase this as a kit from you and then push this through some serious testing for you, all for free. Serious offer on the table. Will report back via email instead of this public debating / flogging platform.
I think the strobing effect is in fact the interlace so I have created a 50 * 7 text display and turned off the interlace just to see if we can get PAL50 on your display.
It works just fine on all my tv sets and 4" LCD (Picture Attached)
The "TV feature" of the propeller is something you can use - or do not. It's advantages are well known: It's cheap as it needs a cord and three transistors and a TV set which is readily available.
I think it was never a matter of "what TV monitor to buy" for the Propeller. This is a misunderstanding and total overkill!
You use a TV or similar screen because it's there!
If you have to calculate budget you:
- either buy (bundle) a true VGA monitor (with a thicker cord)
- or use an alphanumeric display (77480,...)
- or use a graphics display (OLED, KS0108,..)
What any customer expects today is the crystal clear quality of cell phon, pda, or laptop displays.
I aggree there can be special situations where to use compound video due to transmission constraints or needs of the final device... But in those cases NTSC will be fine.
I have expressed my critizism of the incompatibilty of PAL and QVGA screen so many times now, that I shall not repeat this here again
Edit:
I checked some hundred combinations of "lpal", "vvis", and "_xinfreq" last June - without upsetting the whole world - but with little success. I shall not use PAL with the Propeller
Mike_GTN said...
Let no one be surprised however when the Propeller does not see a big market share within the UK.
I don't think I've been reticent in making my own views about PAL support known. The Parallax provided PAL drivers are certainly good enough to get information on screen, superb for debugging and diagnostics ( a genuine USP ), but if I were selling a Propeller-based product I would feel compelled to add a caveat that "PAL video display may not meet all your expectations".
Mike_GTN said...
If it tells me within the specs that the device does PAL video ouput I'd like PAL video output (Not to some bizzare standard however), I don't want to jump through hoops to get almost there.
The Propeller doesn't do video at all until WAITVID is wrapped up in some sort of driver so there's always some hoop jumping involved, but thankfully that's largely avoided for us developers by someone else kindly handing us a driver on a plate.
My measure of successful PAL generation would be when every potential PAL-using customer would be expected to turn round and say, "that works for me and I am happy with what I see". NTSC and PAL60 fails that test, but the latest driver is much closer and perhaps even there.
Yes, true PAL compliance as per the PAL spec is the desirable goal, but everyone happy with what they get, whether genuine PAL or not, is equally good enough for me. If everyone is happy, the market is wide-open. Even if a small minority of PAL-users are not happy with the display, it's still massively open. I feel the PAL market is much more conquerable than it was a couple of weeks ago, and the effort to get us there deserves much praise.
deSilva said...
I aggree there can be special situations where to use compound video due to transmission constraints or needs of the final device... But in those cases NTSC will be fine.
I think that pre-judges what a product will be, NTSC will not be fine in all cases and PAL50 is definitely needed. If nothing else there is a marketing advantage to being PAL50. In some cases ( a few products I'm thinking of ) TV output is fundamental to its low-cost and success and being PAL is a necessity.
Not every Propeller product will need composite video output, not all will require PAL50, but some do, and that's key to those products' existence and success.
The proposed commercial products I'm involved with aren't entirely a no-goer without decent PAL50 but not having that limits their attractiveness, devalues their worth, will increase criticism of the sold product, reduces potential market size aimed for and ultimately doesn't make them economically viable.
Like being fluent only in Esperanto wouldn't stop me writing credible and amazing applications for a PC, but it would limit their appeal, the market and ultimately not make a lot of money nor gain fame and fortune in a largely non-Esperanto speaking world.
My measure of successful PAL generation would be when every potential PAL-using customer would be expected to turn round and say, "that works for me and I am happy with what I see". NTSC and PAL60 fails that test, but the latest driver is much closer and perhaps even there.
I can't speak for PAL, but the NTSC video is pretty solid and I have never seen a TV it hasn't worked on. Infact it provides better video then some video game devices out there where when I hook it up to my video capture card I get sold video, where some of the game devices do not provide as stable of picture.
Hmm, tried both PAL60 & PAL50 drivers - used them with graphics_palette demo - and got noticeable 'crawling' (not sure how else to describe it!) of the blue background (which I don't get with the NTSC driver). Otherwise, the display is similar to NTSC, complete with some dot crawl on contrasting edges, along with some 'shadowing' too.
I suspect it's mostly down to the cheap TV tho'
My setup uses a 10MHz Xtal (_clkmode = xtal2 + pll8x, _xinfreq = 10_000_000), on a cheap Saka 5" TV.
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Cheers,
Simon
www.norfolkhelicopterclub.co.uk
You'll always have as many take-offs as landings, the trick is to be sure you can take-off again ;-) BTW: I type as I'm thinking, so please don't take any offense at my writing style
ok, thanks simonl, maybe it's also the fact that 10Mhz * 16 = 160Mhz internal pll'd not overly sure, or like you say, could be the cheap Saka 5" TV [noparse]:)[/noparse]
either way, cheers for the feedback [noparse]:D[/noparse]
I'll try again with the LCD TV in my lounge - but will have to wait 'til my better half's gone to bed LOL!
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Cheers,
Simon
www.norfolkhelicopterclub.co.uk
You'll always have as many take-offs as landings, the trick is to be sure you can take-off again ;-) BTW: I type as I'm thinking, so please don't take any offense at my writing style
Yeah, I know 10Mhz * 8 = 80Mhz operation, but I was more referencing the fact that the internal PLL goes to 16*, and that maybe that was something to do with it? but I guess we'll have to wait til your better half goes to bed [noparse]:)[/noparse]
Gosh Mrs simonl, is that the time? lol yawn, don't you feel tired? [noparse]:)[/noparse]
Hi People, I promise is really my last chime in on these PAL issues. Perhaps we should tune up the tv object and have two hundred different ones to account for every different TV screen. We could test here with a works for me... etc But then two people might have the same TV and could get different results due to internal changes within the circuits that happen through even simplistic manufacturing changes that happen.
This is really like you buy a brand new car and have to tune it up to get the performance you wish, consumption or other parameters. I'd never expect to have to do a conversion in software from Petrol to Diesel. This without also the details of how to make the conversion.
What about if the video generation hardware was a locked design that could not be tweaked to any major extent? What about if the desingers took short cuts, just to make
the PAL aspect even a possibility. May be for the next generation we should take NTSC as a second best quick fix. you can all have the fun of bit fiddling to get an even half
decent display. I wanted a reasonable display only, and not something outside of the alledged specs of the device. I've found the dot crawl and colour crawl to be really bad - Hey I must have landed in a good thread then after all.
I was just trying to use the PAL50 TV driver with TV text and my newly scrounged old fashioned tube Sony TV. Very disappointing.
OK, we have nice white text on a blue background but the back ground has diagonal bands of brighter/darker blue racing sideways across the screen and horizontal bands of lighter/darker blue slowly scrolling upwards.
The text itself looks OK but is a bit flickery.
I know nothing of PAL or the TV driver but thinking that the diagonal bands might be due to some beating of not quite matched frequencies or some such I started tweaking the PAL color frequency constant in tv.spin (fpal). Surprisingly it works over a large range of values of fpal each of which changes the angle and rate of our diagonal lines. Setting it to 4_433_280 instead of the original 4_433_618 extinguishes the lines visibly. Hurray!
As for the vertical scrolling bands that seems to be something to do with my Props power supply. It injects those bands onto normal channels even when not running any TV driver. As well as a lot of audio hum. No idea how to fix that except that a friend of mine eliminated hum from his TV to computer connection by putting a transformer between the TV and the cable TV wall socket.
The last thing required to avoid epilepsy when using PAL50 is double buffering to get rid of flicker when updating/scrolling.
As a bonus though setting cols = 50 and rows = 15 (as opposed to 40,13) works and gives lots more characters on the screen.
P.S. Why do most of the animated parts of graphicsDemo not move with this package?
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
For me, the past is not over yet.
So in a particularly sadistic moment I jammed my hot soldering iron tip onto my propellers crystal for about a minute. Pretty much nothing happened as it started to fry until eventually, and suddenly, the background went all multicolour stripes. The text remained OK. Poking a moist finger on the crystal pins has much the same effect.
More seriously, would it help to drive the Prop with a PAL colour frequency crystal, 4_433_618Hz? This way the fpal frequency would be spot on and everything else going on in the Prop would be in synch with it.
Or is all this to do with my home made Prop Demo Board style board built on a generic prototyping card with a DIP Prop and through hole resistors etc?
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For me, the past is not over yet.
hm well, i've been testing the TV-Pal-Output. I can see the color, but it flickers a bit an, whats the main Problem for my use: The created image doesn't fill the screen completely. There's room at the top/bottom and the left/right side! How can i expand the picture?
propwell, can you explain a little more?
What tile sizes are you using? does it create a res of 256x192? if so, yes, PAL image will have room on top/bottom and left and right
You can increase the HX values, to get wider pixels, to help sort out the edges.
but as for top and bottom borders, that's because PAL has more raster lines than NTSC.
Can you post pics?
When I started to play with the prop, a couple of months ago, I went for the OBEX NTSC objects just to test things out. My monitor will autosence the incoming standard but PAL was what I wanted.
I tried the original 5MHz and got severe coarse diagonal bacground patterning, with 6MHz, with appropriate corrections, it was a nice clear pic. So I though use 4.43 (with code corrections) and hopefully gove the internals some nice easy sums to do, this did not work all I got was an unlocked mess. The same was true with 8.86 (w.c.c)
I thought it was due to a minimum "80Mhz" clock sort of thing and gave up (I suppose 17.74 would be classed as a crime against silicon)
Look at the archive below, I have modified it to fill as much as the PAL display area as possible.
It's more of an example of what can be done just by tweaking the existing settings.
I have tested this on a Parallax demoboard and on my setup which is a 3" LCD (From Brillidea) and my Hybrid board that runs with a 6MHz crystal.
The archive attached is setup for the Parallax demoboard.
There is some dot crawl when running with a 5MHz crystal but I'm sure with a few tweaks this could be overcome.
Regards,
Coley
NOTE that the attached file will need to renamed to .zip as the forum wouldn't let me upload the zipped archive for some reason
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ PropGFX - The home of the Hybrid Development System and PropGFX Lite
There will always be some dot crawl, it is built into the whole system. The 1135/4 +25 formula that gives the 4.43 figure was always the best fudge that they could handle. On normal resolution, moving TV pic it was bearable. Start drawing fine coloured lines on CRTs with poor triad pitch and there will be greif. We have got used to 1024X768 as being normal and it hurts to go backwards. Imagine still having a 8088 feeding CGA, fantastic 20 years ago, retro now.
My original problems were the beating of the background blue.
Comments
Seeing as you have the most expertise amongst us wrt PAL video signals, perhaps you could supply us with the defacto definition and breakdown of it.
That way we could construct a more accurate driver.
Coley
Regards
Mike.
Regards,
Coley
This one is for you my friend.
I think the strobing effect is in fact the interlace so I have created a 50 * 7 text display and turned off the interlace just to see if we can get PAL50 on your display.
It works just fine on all my tv sets and 4" LCD (Picture Attached)
Coley
Leon
·
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Amateur radio callsign: G1HSM
Suzuki SV1000S motorcycle
Post Edited (Leon) : 1/12/2008 12:40:17 PM GMT
I think it was never a matter of "what TV monitor to buy" for the Propeller. This is a misunderstanding and total overkill!
You use a TV or similar screen because it's there!
If you have to calculate budget you:
- either buy (bundle) a true VGA monitor (with a thicker cord)
- or use an alphanumeric display (77480,...)
- or use a graphics display (OLED, KS0108,..)
What any customer expects today is the crystal clear quality of cell phon, pda, or laptop displays.
I aggree there can be special situations where to use compound video due to transmission constraints or needs of the final device... But in those cases NTSC will be fine.
I have expressed my critizism of the incompatibilty of PAL and QVGA screen so many times now, that I shall not repeat this here again
Edit:
I checked some hundred combinations of "lpal", "vvis", and "_xinfreq" last June - without upsetting the whole world - but with little success. I shall not use PAL with the Propeller
Post Edited (deSilva) : 1/12/2008 1:13:23 PM GMT
I don't think I've been reticent in making my own views about PAL support known. The Parallax provided PAL drivers are certainly good enough to get information on screen, superb for debugging and diagnostics ( a genuine USP ), but if I were selling a Propeller-based product I would feel compelled to add a caveat that "PAL video display may not meet all your expectations".
The Propeller doesn't do video at all until WAITVID is wrapped up in some sort of driver so there's always some hoop jumping involved, but thankfully that's largely avoided for us developers by someone else kindly handing us a driver on a plate.
My measure of successful PAL generation would be when every potential PAL-using customer would be expected to turn round and say, "that works for me and I am happy with what I see". NTSC and PAL60 fails that test, but the latest driver is much closer and perhaps even there.
Yes, true PAL compliance as per the PAL spec is the desirable goal, but everyone happy with what they get, whether genuine PAL or not, is equally good enough for me. If everyone is happy, the market is wide-open. Even if a small minority of PAL-users are not happy with the display, it's still massively open. I feel the PAL market is much more conquerable than it was a couple of weeks ago, and the effort to get us there deserves much praise.
I think that pre-judges what a product will be, NTSC will not be fine in all cases and PAL50 is definitely needed. If nothing else there is a marketing advantage to being PAL50. In some cases ( a few products I'm thinking of ) TV output is fundamental to its low-cost and success and being PAL is a necessity.
Not every Propeller product will need composite video output, not all will require PAL50, but some do, and that's key to those products' existence and success.
The proposed commercial products I'm involved with aren't entirely a no-goer without decent PAL50 but not having that limits their attractiveness, devalues their worth, will increase criticism of the sold product, reduces potential market size aimed for and ultimately doesn't make them economically viable.
Like being fluent only in Esperanto wouldn't stop me writing credible and amazing applications for a PC, but it would limit their appeal, the market and ultimately not make a lot of money nor gain fame and fortune in a largely non-Esperanto speaking world.
I suspect it's mostly down to the cheap TV tho'
My setup uses a 10MHz Xtal (_clkmode = xtal2 + pll8x, _xinfreq = 10_000_000), on a cheap Saka 5" TV.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Cheers,
Simon
www.norfolkhelicopterclub.co.uk
You'll always have as many take-offs as landings, the trick is to be sure you can take-off again ;-)
BTW: I type as I'm thinking, so please don't take any offense at my writing style
either way, cheers for the feedback [noparse]:D[/noparse]
I'll try again with the LCD TV in my lounge - but will have to wait 'til my better half's gone to bed LOL!
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Cheers,
Simon
www.norfolkhelicopterclub.co.uk
You'll always have as many take-offs as landings, the trick is to be sure you can take-off again ;-)
BTW: I type as I'm thinking, so please don't take any offense at my writing style
Gosh Mrs simonl, is that the time? lol yawn, don't you feel tired? [noparse]:)[/noparse]
Cheers,
Jim.
This is really like you buy a brand new car and have to tune it up to get the performance you wish, consumption or other parameters. I'd never expect to have to do a conversion in software from Petrol to Diesel. This without also the details of how to make the conversion.
What about if the video generation hardware was a locked design that could not be tweaked to any major extent? What about if the desingers took short cuts, just to make
the PAL aspect even a possibility. May be for the next generation we should take NTSC as a second best quick fix. you can all have the fun of bit fiddling to get an even half
decent display. I wanted a reasonable display only, and not something outside of the alledged specs of the device. I've found the dot crawl and colour crawl to be really bad - Hey I must have landed in a good thread then after all.
Mike.
OK, we have nice white text on a blue background but the back ground has diagonal bands of brighter/darker blue racing sideways across the screen and horizontal bands of lighter/darker blue slowly scrolling upwards.
The text itself looks OK but is a bit flickery.
I know nothing of PAL or the TV driver but thinking that the diagonal bands might be due to some beating of not quite matched frequencies or some such I started tweaking the PAL color frequency constant in tv.spin (fpal). Surprisingly it works over a large range of values of fpal each of which changes the angle and rate of our diagonal lines. Setting it to 4_433_280 instead of the original 4_433_618 extinguishes the lines visibly. Hurray!
As for the vertical scrolling bands that seems to be something to do with my Props power supply. It injects those bands onto normal channels even when not running any TV driver. As well as a lot of audio hum. No idea how to fix that except that a friend of mine eliminated hum from his TV to computer connection by putting a transformer between the TV and the cable TV wall socket.
The last thing required to avoid epilepsy when using PAL50 is double buffering to get rid of flicker when updating/scrolling.
As a bonus though setting cols = 50 and rows = 15 (as opposed to 40,13) works and gives lots more characters on the screen.
P.S. Why do most of the animated parts of graphicsDemo not move with this package?
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
For me, the past is not over yet.
So in a particularly sadistic moment I jammed my hot soldering iron tip onto my propellers crystal for about a minute. Pretty much nothing happened as it started to fry until eventually, and suddenly, the background went all multicolour stripes. The text remained OK. Poking a moist finger on the crystal pins has much the same effect.
More seriously, would it help to drive the Prop with a PAL colour frequency crystal, 4_433_618Hz? This way the fpal frequency would be spot on and everything else going on in the Prop would be in synch with it.
Or is all this to do with my home made Prop Demo Board style board built on a generic prototyping card with a DIP Prop and through hole resistors etc?
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
For me, the past is not over yet.
Thanks,
Propwell
What tile sizes are you using? does it create a res of 256x192? if so, yes, PAL image will have room on top/bottom and left and right
You can increase the HX values, to get wider pixels, to help sort out the edges.
but as for top and bottom borders, that's because PAL has more raster lines than NTSC.
Can you post pics?
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http://www.propgfx.co.uk/forum/·home of the PropGFX Lite
·
I tried the original 5MHz and got severe coarse diagonal bacground patterning, with 6MHz, with appropriate corrections, it was a nice clear pic. So I though use 4.43 (with code corrections) and hopefully gove the internals some nice easy sums to do, this did not work all I got was an unlocked mess. The same was true with 8.86 (w.c.c)
I thought it was due to a minimum "80Mhz" clock sort of thing and gave up (I suppose 17.74 would be classed as a crime against silicon)
Look at the archive below, I have modified it to fill as much as the PAL display area as possible.
It's more of an example of what can be done just by tweaking the existing settings.
I have tested this on a Parallax demoboard and on my setup which is a 3" LCD (From Brillidea) and my Hybrid board that runs with a 6MHz crystal.
The archive attached is setup for the Parallax demoboard.
There is some dot crawl when running with a 5MHz crystal but I'm sure with a few tweaks this could be overcome.
Regards,
Coley
NOTE that the attached file will need to renamed to .zip as the forum wouldn't let me upload the zipped archive for some reason
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
PropGFX - The home of the Hybrid Development System and PropGFX Lite
Post Edited (Coley) : 4/11/2009 9:58:48 AM GMT
My original problems were the beating of the background blue.