Pinout on Agnus?
6 messages in this thread
Does anyone have schematics for the A500. I'm attempting to speedup mmy
A500 using Leslie Aylings hack, I need to know which pin on Agnus is Pin
34. Do I start counting at the dot (located at the center of one side, one
being the pin that corresponds to the dot and the two pin starting
counterclockwise. Thanx John
The method you gave is the standard way to count PLCC pins. And I do have
A500 schematics in my A500 manual. If you e-mail me your address I'll
(u.s.)mail you a copy of them (plus the short appendices on each of the
chips).
– Eric Staubly
John,
Yes…pin #1 is in the center…by the dot. And you count
counter-clockwise (looking at the chip from the top).
Pin #34 is the 2nd pin from the left on the "bottom" …that is,
the side opposite pin 1.
Don
Don and John,
I have (on page F-3 of the A500 manuel, for the FAT agnus) pin 34 being the
THIRD up from the bottom. The 28Mhz clock input. The manuel was printed in
'87.
David,
Hummm…interesting. I've got it from the insert that came with
the original A2000's. I never counted the pins on the chip, but it shows
it as an 84 pin PLCC chip. Thus, it'd have 21 pins per side. With pin #1
being in the middle of the "top"…pin #11 would be the top leftmost pin.
Add 21 and pin 32 would be the left bottom pin, 33 would be the first pin
on the bottom left, and 34 (which is 28Mhz clock input) the 2nd from the
left on the bottom.
Well..actually, I just remembered I do have an extra Agnus chip
sitting here in my drawer. So looking at it…and counting…pin #34 is
definately the 2nd from the left on the bottom of the chip…as described
in the insert I have.
That does make sence. Looking back over the diagram, I relised that I was
not looking at a true pin-out, but a wiring diagram. Pg A-16 on the Fat
Agnus, agree's with your insert. I'm glad I wasn't the FIRST to respond
to the question <G>.
David D.