Re: [stella] PAL Sound Conversion

Subject: Re: [stella] PAL Sound Conversion
From: erik@xxxxxxxxxx
Date: Sat, 09 Feb 2002 23:31:00 -0500
>I'm trying to make a PAL version of the Synthcart.  The colors are not a 
>problem.  The main problem is the pitch and tempo.
>The tempo is calculated by counting TV frames.  For example, one setting is 
>that a beat occurs every 3 frames.  My understanding is that even if I 
>leave it at 262 lines, the tempo will be different because the clock runs 
>at a slightly different speed.  By my calculation, a TV frame of 262 lines 
>will take 16841 microseconds on a PAL system (vs 16686 on NTSC.)  If this 
>is correct, I should be able to calculate the tempos fairly accurately.

That is correct, by my calculations as well.  According to Google, the
NTSC color clock is 3.579545 MHz and PAL is 3.546894 MHz.
228*262*NTSC = 16688.15 microsec (although you said 16686), and
228*262*PAL = 16841.78 microsec.

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