Re: Well, back into a IIe I am

[mjmahon@aol.com (Michael J. Mahon)]

Matt Jenkins wrote:

>On Mon, 08 Dec 2003 19:20:40 +0000, Michael J. Mahon wrote:
>
>> I'd always wondered why the PAL Apples had the AUX slot in line
>> with slot 3--picking up -12v sounds like the answer.
>
>That's the answer, but the machines aren't actually PAL; The video
>frequency has been changed to 50Hz, but the color-burst signal coming
>from the board is the same quasi-ntsc signal generated by US Apple II's.
>The was a modified extended 80 column card for Euro standard markets
>that delivered a PAL signal on a seperate connector on that card. Once
>the platinum IIe was released these became unavailable as the platinum
>IIe shipped with the same minature card here as in the US. Additionally
>Apple's Composite Colour monitor was capable of generating a colour
>picture from the 50Hz Apple's. Although for some reason the pre-platinum
>Euro boards produce 'wrong' colours from their composite port when
>connected to this display (which is I think the real reason the fancy
>80 column card was created)
>
>One thing that's really frustrating these days is that even with
>multi-mode tv's that support either a PAL or NTSC signal, you still can't
>get colour out of the Euro models on a TV set, as most of them seem to
>assume a PAL signal because of the 50Hz refresh. On the original II and
>II+, the 50 Hz version is created by cutting special pads on the
>motherboard (and maybe some other things, can't remember right now, it's
>in the Apple II Reference manual) so you can at least reverse it and
>create a real 60Hz ntsc signal. Unfortunately there's no easy way to do
>this on a IIe.

ISTR that Apple just changed the vertical frequency, but left the color
burst (and implicit subcarrier) at the NTSC 3.58MHz.  I suppose that
a main crystal change could bring the burst frequency to the PAL
standard, by shifting the frequency of everything a bit.

-michael

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