Re: [stella] Number of Scanlines

Subject: Re: [stella] Number of Scanlines
From: "Eric Ball" <ericball@xxxxxxxxxxxx>
Date: Sat, 7 Dec 2002 16:20:23 -0500
Just my two cents on the matter:

>From a horizontal perspective, the 2600 creates a slightly out-of-spec
signal since it is 228 pixels wide, with the pixel clock being equal to the
colourburst.  But NTSC colourburst is 227.5 x FH (horizontal frequency,
which is 60Hz * 1000/1001 * 525/2).  And except for the recent interlacing
demos, the 2600 doesn't create separate fields.

When it comes to number of lines, it is possible to have up to 240 active
lines (DVDs have 480 using both fields).  You would have 4 VBLANK lines
before and 15 lines after the 3 lines of VSYNC.

This is for NTSC, of course, PAL is a different beast entirely.

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