Commodore Amiga A500 Technical Reference Manual page 80

High Voltage Supply
( + 12V)
Negative High Supply
(-12V)
CLOCK SIGNALS
/C1 Clock
/C3 Clock
CDAC Clock
E Clock
Higher voltage supply, useful for communications cards and other
devices requiring greater than digital voltage levels. This is intended
for small loading only; there's a total of 8 Amps for the entire
A2000 system, much of which is normally devoted to floppy and
hard disk drive motors. Pound on all instances of the Expansion Bus,
though the available currents may vary. Pin: 10.
Negative version of the high voltage supply, also commonly used in
communications applications, and similarly intended for small loads
only; there is a total of 03 Amp for the entire A2000 system. This
pin is an extension of the original Zorro specification, and is found in
all A2000 machines. Pin: 20.
The Expansion Bus provides clock signals for expansion boards. They
are generally used to allow clocked logic to be used in designs
instead of delay lines. See p. 39 for bus loading specs.
This is a 3.58 MHz clock synched to the falling edge of the 7.16
MHz system clock. Also known as /CCK in some places. Pin 16.
This is a 3.58 MHz clock synched to the rising edge of the 7.16
MHz system clock. Also known as /CCKQ in some places. Pin 14.
This is a 7.16 MHz clock that leads the 7.16 MHz system clock by
70ns (90 degrees). Pin 15.
This is the 68000 generated "E" clock, used for 6800 family peri-
pherals driven by "E" and 6502 peripherals driven by PHI2. This
clock is six 7.16 MHz clocks high, four clocks low. as per the 68000
spec. Pin 50.
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