1 Sep
2011
1 Sep
'11
5:28 p.m.
On 01/09/2011 22:47, Tony Duell wrote:
I remember the warning, I just didn't remember there being different
crystals. So I dug out my Europlus, and sure enough, I misremembered.
The crystal is 14.25045MHz instead of 14.31818MHz.
Oops, sorry!
--
Pete Peter Turnbull
Network Manager
University of York
>> Silly question of the day: I'm guessing
no-one would have any idea where
>> I'd find a 14.25045MHz crystal in New Zealand...
No, but the
standard crystal in an Apple ][ is a 14.318MHz crystal, and
that's a standard so should be very easy to find. I wonder if yours is
a special value for a non-US market? But AFAIR even the Apple Europlus
used 14.318MHz.
I've not batteld throught the timing circuitry, but the Apple ][
Reference Manual includes a section entitled 'Eurapple (50Hz)
Modification' which describes the cut-n-jumper pads on the mainboard. It
ends with 'Warning : This modification will void the warranty on your
Apple and requires the installation of a different main crystal. This
modification is not for beginners'. So it appears the crystal is
different for US and European models.