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Hello :)

I can see that other emulator than mine (not only for SMS, yet also for others systems) can produce images like an original arcade game. It´s an effect that I know that is called scanlines.

The quiestion is: How to make scanlines with my emulator?

Thanks

Quote

> The quiestion is: How to make scanlines with my emulator?

There's two ways to do it, I'll explain both.

The easy way is to use a video mode that has double the
vertical resolution. If you are displaying a 256x192 image in
a 320x200 display, then you'd use 320x400, and copy every line
of the source image to every *other* line of the screen.
This makes single black line between each visible line of the
display.

Remember that unless you've changed the border color, any
modifications to color zero will affect the area between
display lines. What I do is set the border color to 0xFF, then
set that color to black.

The other method is by tweaking the display to have less scan
lines, which has the side effect of boosting the vertical
refresh rate. Then you can use your monitor settings to
'stretch out' the display to fit the monitor, and you'll get
real 'scanlines', that is, space between each line of the
physical display. The advantage of this method is that
you don't need to alter the way you copy data to the screen,
since it's all done in hardware by the VGA for you.

Doing this is a bit complex, but the basic premise is to
set the vertical display end and blanking start to 255 lines, alter vertical retrace
so the display is near the bottom of the screen, then reduce
the vertical total and vertical blank end until you reach
the desired refresh rate. I find setting both of those values
to between 0x20-0x40 works well for the scanlines trick, and
gives a decent refresh rate most multisync monitors can handle.

Hope that helps.

Author	Message
Jose Manuel Delgado Mendi Guest	Scanlines Posted: Wed Dec 08, 1999 11:22 am
Jose Manuel Delgado Mendi Guest	Hello :) I can see that other emulator than mine (not only for SMS, yet also for others systems) can produce images like an original arcade game. It´s an effect that I know that is called scanlines. The quiestion is: How to make scanlines with my emulator? Thanks

Charles MacDonald Joined: 28 Sep 1999 Posts: 1197	Posted: Thu Dec 09, 1999 9:22 pm
Charles MacDonald Joined: 28 Sep 1999 Posts: 1197	Quote > The quiestion is: How to make scanlines with my emulator? There's two ways to do it, I'll explain both. The easy way is to use a video mode that has double the vertical resolution. If you are displaying a 256x192 image in a 320x200 display, then you'd use 320x400, and copy every line of the source image to every other line of the screen. This makes single black line between each visible line of the display. Remember that unless you've changed the border color, any modifications to color zero will affect the area between display lines. What I do is set the border color to 0xFF, then set that color to black. The other method is by tweaking the display to have less scan lines, which has the side effect of boosting the vertical refresh rate. Then you can use your monitor settings to 'stretch out' the display to fit the monitor, and you'll get real 'scanlines', that is, space between each line of the physical display. The advantage of this method is that you don't need to alter the way you copy data to the screen, since it's all done in hardware by the VGA for you. Doing this is a bit complex, but the basic premise is to set the vertical display end and blanking start to 255 lines, alter vertical retrace so the display is near the bottom of the screen, then reduce the vertical total and vertical blank end until you reach the desired refresh rate. I find setting both of those values to between 0x20-0x40 works well for the scanlines trick, and gives a decent refresh rate most multisync monitors can handle. Hope that helps.

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