Re: [stella] playfield on-the-fly updates

Subject: Re: [stella] playfield on-the-fly updates
From: Chris Wilkson <cwilkson@xxxxxxxxxxxxxxxx>
Date: Mon, 18 May 1998 11:34:23 -0700 (PDT)
> I have just opened one of my PAL junior VCSs to see what frequency
> they are running at. I don't know much about electronics, but I think
> the clock is in a part labeled 'PIC 3.546896 MHz'. There is another
> part like this, which is labeled 'HOORAY 4.433618', but I don't know
> what it is for. The numbers were a bit hard to read, but I believe
> I got them right. So, what speed do NTSC VCSs run at?

Sounds like you have 2 clock cystals.  Could one be for SECAM? It's
interesting to note that 3.54 is 80% of 4.43.  Sounds like it's a dual
standard machine.  NTSC runs at 3.5795MHz.  Actually, if you use the the
3.54MHz crystal, that's "close enough" to NTSC.  And if you use the 4.43MHz
cystal, you can get 324 scanlines at 60Hz, or 388 scanlines at 50Hz.
Sounds kinda "convenient" to me.  If anyone here has an extra PAL 2600 jr,
and could send it to the states, I'd really like to disect one.

-Chris


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