Re: What's the IIe's--Arghh!--MHz Speed?

[david@uow.edu.au (David Wilson)]

Patrick Schaefer <pa.schaefer@fz-juelich.de> writes:
>Kent Dickey wrote:

>> The nominal 1MHz clock is derived from a base crystal 14MHz = 14318180.

>...unless you live in Europe. The ][europlus versions have a main
>oscillator with 14.025xxx MHz, therefore our machines are a little
>slower. This was required to get the 50Hz timing for PAL tv.

It is (according to Jim Sather) 14.25 in //e with hybrid oscillators
and 14.25045 in //e with discrete oscillators. This is not to get the
50Hz vertical refresh (this is done by the 50Hz IOU adding 50 scans
[262->312 lines]) but to get the horizontal refresh closer to 64us
[15625Hz instead of 15725Hz]).

I must have a unique collection of //e video systems:

1)	MPF-III (//e clone)	NSTC	50Hz
2)	//e			PAL	60Hz
3)	//e			PAL	50Hz
4)	platinum //e		NTSC	50Hz (I think - has RGB card & mon)

#2 is to fix the Meg80z problem with 50Hz systems. I have run #1..3
into a multistandard TV and #1 gives the best colors.
--
David Wilson  School of IT & CS, Uni of Wollongong, Australia  david@uow.edu.au