Apple // europlus
ard at p850ug1.demon.co.uk
Tue Feb 19 15:28:13 CST 2008
> Roger Holmes wrote:
> > On 19 Feb, 2008, at 18:00, cctalk-request at classiccmp.org wrote:
> >> From: Tim Riker <Tim at Rikers.org>
> >> I'm not sure what a europlus version of the machine is though.
> > The euro means 110/240 volt switchable power supply. I don't think there
> > was any other change, though it was common to have a colour card (in
> > slot 7?) which took the NTSC signal, decoded it and re-coded into PAL. I
> > guess there was a corresponding SECAM card for France. As you probably
> > know, the plus mean floating point Basic.
> That is odd -- years ago when I studied the video logic in the II+,
> there were jumper options for PAL that changed the video timing.
> Perhaps it wasn't good enough and thus the NTSC->PAL conversion boards,
> but the cut & jump traces were certainly there.
Those jumpers certainly exist (on all mainboards other than very early
ones iIRC) amd are documented in the reference manual. And yes, on a
Eruoplus (AFAIK) they've been cut/soldered to give 50Hz video timing.
But note, an Apple ][ with this done does not output PAL video. What it
outputs is 50Hz vertical video, but with an NTSC-like colour encoding.
One of the colour difference cignals is _not_ inverted every other line,
as it should be for PAL.
And that's what the PAL converter board in slot 7 does. It outputs a true
PAL signal. But you have to fo the cut and jumper mod too, to get 50Hz
> I could be mistaken, but I think another feature added by the + was the
> "color killer" feature -- a control bit that removed the color burst
> signal so that you'd get true B&W video when you just want straight text.
I thought that was on all mainboards other than the very early ones
(along with the decoding of the MSB of the grahpics memory area to give
the orange/blue colours). 'Plus' to me maean Applesoft BASIC in ROM
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