Apple // europlus

[Tony Duell]

> 
> 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 
timing.

 
> 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

-tony