Mode line versions

[rambo1152]

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 .

When I looked at UK sellers in lowest BIN ebay sales, they were about £6 without, and £10 with. Including postage in many cases.

[rambo1152]

Originally Posted by 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.)

Our first TV was either an HMV1802 or an 1805 I remember Andy Pandy, The Woodentops, Testcard C, and even the black on white cruciform "Art Bars", but not the line whistle, but would I have noticed at seven years old (me, not the TV) when it was replaced with an HMV1871?

That set certainly whistled, and was phenomenally reliable throughout its 20 year lifetime.

I don't seem to be able to hear 10,125Hz now though.

[peter_scott]

Graham,

I think young people generally have a better frequency range than adults. It's funny that you don't hear 10.125kHz now, I hear it all the time regardless of where I am.

Peter

[rambo1152]

I do hear it all the time, just not via my ear canals

I have started a new thread.

[dalekmoore2007]

Originally Posted by peter_scott

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.

Thanks Peter i will check, i think i am right now working out what to look for and order.
BTW is there a link if you ever posted it on your scope tv for 240 line circuit ?

[dalekmoore2007]

Originally Posted by 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.

Wow that's interesting and a great idea ,its the programming that is the main problem for most of us like me ..wonderful idea for sure Julie !

[peter_scott]

Originally Posted by 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.

I was wrong about the lower line rate limit. The modeline editor does reject some inputs but if you save them (with reboot) then they can be accepted.

Here for example is 120 lines with 25Hz frame rate.

Modeline "1500x100_25 3.0kHz" 8.840 1500 2828 2938 2948 100 105 110 120 -hsync -vsync

Peter

[dalekmoore2007]

Great news Peter ! how far down can you go out of interest !
it sounds like it at least can do every thing 100 lines above to 625 or more ?
Below is something of interest what is possible .
Also can it do 12.5 frame rate ?

[peter_scott]

I think with my graphics card the Dot-Clock needs to be greater than 8.000 and the HTotal needs to be less than 3000.

So 107 lines is about the lower limit for me operating at 25 Hz frame rate, and if I halved the frame rate I think the line count would need to double.

Dot-Clock = Frame rate * HTotal * VTotal

Modeline "String description" Dot-Clock HDisp HSyncStart HSyncEnd HTotal VDisp VSyncStart VSyncEnd VTotal

Modeline "1500x100_25 2.7kHz 25.0Hz" 8.020 1500 2828 2938 2999 100 103 105 107 -hsync -vsync

Peter

[dalekmoore2007]

Thanks Peter now i know the low end for sure with this method the low end.