Re: No colour video from Apple II Europlus

["David Wilson" <mcs6502@gmail.com>]

Kallikak wrote:
> It seems that Tom is right, and the NTSC hack that gives colour smiply
> doesn't work with PAL, and the Europlus PAL adjustment is really only
> an adjustment of the frequency down to 50Hz.

Yes, I agree as well.

> I've been watching that ebay link, but pretty much everything that guy
> has been selling is being bought by one person who seems to be
> unhindered by such mundane concerns such as cost!  :-)

I think I have a spare PAL color card if you want one.

> So my question is now, does anyone have specific details for switching
> the Apple II back to NTSC?  There are some soldered jumpers that need
> to be changed - that's no problem (as long as I know which ones), but
> if it also needs an oscillator changed, I may have more problem finding
> an appropriate part.

Revert jumper changes to change number of scanlines from 312 (PAL) to
262 (NTSC).
Change main oscillator crystal from 14.25MHz to 14.18318MHz to change
horizontal scan rate from 15625Hz to 15725Hz.
That should be it.