#NTSC/PAL Jumper?
3 messages in this thread
I was lead to understand that Obese Agnes would allow my Amy to switch from
NTSC to PAL based on the placement of jumper J102. Today I discovered that
there is no J102 on my machine (rev 4.2 B2000), just a couple of solder
spots and the letters 'J102'. Since I understood that the absence of the
jumper set PAL, the solder spots appear to be unconnected, and my machine
is definitely NTSC, does this mean that PAL is unachievable on a rev 4.2
machine?
A quote from Dave Haynie (the designer of the A2000):
J102 controls whether the 1 Meg Agnus powers up in NTSC or PAL
mode. If the jumper is closed (as shipped) you get NTSC, if open PAL. The
old style Agnus used this pin for some test function and we required
separate chips for PAL and NTSC.
In other words…it has nothing to do with the rev of the
motherboard. I also seem to recall that the Amiga autosenses 50Hz or 60Hz
power lines and based on that sets NTSC or PAL mode (I could be wrong on
that though).
I have a rev 4.2 motherboard and there is a spot labeled J102, but
there isn't any jumper there, just a pair of solder patches where I would
expect it to be installed. Looking from the top of the motherboard it
looks as if the patches are unconnected, which is why I was wondering if
there was a difference. If there isn't a difference between revisions I
expect that there is a connection of some sort on the bottom of the
motherboard where I can't see it without a bit more work.