Mode line versions

[dalekmoore2007]

Reading up on the forum about getting modeline program trying to get it to work with my graphic chip and the procedure to make it work .
I have noticed in one procedure i have found on the forum that a composite box is ticked I don't have this box but it's the same version of the program?

As in screen grabs below?

[peter_scott]

Perhaps the Nvidia card doesn't allow for composite sync.

I think the Modeline images you have seen are with ATI graphics card.

Peter

[peter_scott]

Here's a set of Modelines that I have used that includes one for 625 that I think you are planning to use.

Peter

[dalekmoore2007]

Hi Peter
Thanks for the reply ...i think understand now it depends on what graphic chip you are using and it will show up in the menu if i am right?
Yes I am planning just 625 line as a test to see if the thing works with my computer and monitor.
I have always wanted to make a 405 line television just for the hell of it but needed a test video signal reason i went looking what was possible .
I rather home brewing gear takes the fun out of it for me just buying every thing ..
But i am also making a multi system monitor to do line numbers mainly 64 lines up it can do 32 also but i am trying for non standard 128 256 512 .
If that works out i will try another idea i have to make it do all the early Tv standards .
Harry

[peter_scott]

Hi Harry,

I've made some minor tweeks to my 405 modelines and the broadpulse monostable that now give a rather better approximation to the spec.

See: http://golbornevintageradio.co.uk/fo...74306#pid74306

You may need to refresh your browser / clear its cache to see the updated version.

Peter

[dalekmoore2007]

Thanks Peter for the link there it looks really good i can't wait to try it when i get the correct graphics card .
I was meaning to ask is the PCI nVidia Quadro NVS 285 graphics adapter the one you are using ?
Also is there a list of other PCI graphic cards that work ,is there one better than the other ?
I picked up an old Pentium 4 for a start to try it happened to have a vga and 625 line composite out video card and that works i looked if it might work with mode line but no goer there!
It also had a old tv card but the program drivers on the hard drive were long gone..any case i just got the computer for the future compatible graphic's card for mode line .

[rambo1152]

I initially had success with the nVidia Quadro NVS 285 under Windows XP
to get it working under Windows 7, I had to change the card to a ATI Radeon HD 2400 Pro.
The results on the 405 line picture were exactly the same in both cases.

I understand from a brief email exchange I had with Jeroni Paul, that for each given graphics driver, he has to incorporate certain code mappings into Winmodelines.

I don't know what the situation is with later Windows versions

Peter had a longer email exchange with Jeroni, so he can probably say more,

[peter_scott]

Originally Posted by dalekmoore2007

I was meaning to ask is the PCI nVidia Quadro NVS 285 graphics adapter the one you are using ?

No, like Graham I changed to an ATI Radeon HD 2400 Pro after consulting Jeroni Paul so that I could use Windows 7.

Peter

[dalekmoore2007]

Thanks Graham and Peter for the replies ,i am glad i asked !
i will look into ordering a ATI Radeon HD 2400 Pro , i put windows 7 on the desk top i just got so that's good to !
i know it can do 240 line and 405 has any one tried the german 180 line ,i know it comes down to a monitor to view it ,but Peter i suppose you could do it on a scope tv or what i hope to do with The Thylacine higher line rate monitor Link here
http://www.taswegian.com/NBTV/forum/...=2436&start=45
i also wonder what the lowest limits are on mode line working ? might be also be able to do below 100 lines in the NBTV area ?
I have a monitor here as well The tasmanian devil that will do lower line rates
http://www.taswegian.com/NBTV/forum/...hp?f=31&t=2391

[peter_scott]

Originally Posted by dalekmoore2007

i know it can do 240 line and 405 has any one tried the german 180 line

I think the answer is yes. I haven't bothered to sort the sync pulse widths but you can see my modeline is the last in my set. I am displaying the image on my HMV901 but without component changes I can't run the line timebase slow enough so I have two frames side by side.

Peter

[peter_scott]

Sorry! There must be something wrong with this. I'll give it some more thought.

Peter

[peter_scott]

The modeline editor accepted my modeline but my graphics card refused to respond correctly with the rather low pixel clock rate involved. I've tried various modelines now but the lowest line rate that I can get to work is 200 as shown below.

Peter

[rambo1152]

The line whistle must be annoying.

[peter_scott]

When you don't have a line output stage with flyback EHT generation line whistle is inaudible. (Or perhaps I'm just deaf as a post.)

Peter

[dalekmoore2007]

Thanks again here Peter and Graham ..
So about 200 lines are the limit in mode line ? is that with 50 or 25hz framing ?
I wonder why i would think it would be the other way around trying higher line rates .
Its a pity we could not test different brands to see unless some one else on the forum has a different one to test this .
Graham as you know most tvs use the horizontal for the eht generation ,i went a different way with my monitor i am constructing ,has its own inverter which is independent of the horizontal so just a matter of what the yoke can cope with frequency wise which is wider than i would of expected but do have to put up with adjusting screen size raster position .
Peter so if 200 lines is the lowest limit we would need some thing like my circuit Steve Anderson came up with for me on my monitor feeding this to a 4040 ic out put would divide by 2 4 8 16 so on to get the lower line rate's down to the NBTV standards 256 lines or higher would be some thing to try this way to get down to 64 and 32 lines .
Chart showing line frequency left with frame rate top resulting line numbers
Can the framing be dropped to 12.5 hz ?
again a divide by 2 circuit can fix this and mix the sync to a composite video or just feed to a scope circuit as think you did for the 240 line experiment.
so one way or another electronics will find a way
I looked into the video card some sellers a pretty cheap i should be able to order one in a week or 2 .

[peter_scott]

I don't think the lower limit is due to the modeline generation. When discussing this with Jeroni Paul he suggested that the pixel clock rate of my graphics card was the limiting factor at about 8MHz. Other cards may offer lower clock rates but I don't know enough to suggest one.

The 200 line image was generated with a 25Hz frame rate so flickering nicely just like the Baird 240 lines.

Peter

[dalekmoore2007]

OH i forgot does any one know if the splitter cable comes with the graphics card or its some thing i have to buy as well ...i will have to look into this when looking at whats for sale .

[dalekmoore2007]

Originally Posted by peter_scott

I don't think the lower limit is due to the modeline generation. When discussing this with Jeroni Paul he suggested that the pixel clock rate of my graphics card was the limiting factor at about 8MHz. Other cards may offer lower clock rates but I don't know enough to suggest one.

The 200 line image was generated with a 25Hz frame rate so flickering nicely just like the Baird 240 lines.

Thanks Peter i now know what to expect with whats on offer with your card so least i know this now .
I suppose its pot luck what works or not ,i would stick with what i know you guy's are using or i might end up getting something thats doesn't work at all .

[peter_scott]

Originally Posted by dalekmoore2007

OH i forgot does any one know if the splitter cable comes with the graphics card or its some thing i have to buy as well ...i will have to look into this when looking at whats for sale .

On eBay I've seen sellers offering cards both with and without the splitter. I bought mine separately but the advert will definitely say if it includes the cable.

Peter

[julie_m]

Just thinking out loud, TV resolution is hardly beyond the ken of a pure software solution, running on the main CPU -- there's no real need anymore for it to be done with dedicated hardware. If the motherboard has a header for a printer port, this could be used with just a few resistors and an NPN transistor to output the video signal.