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The 6502 CPU contains a
status register and each
individual bit is a
FLAG.
A flag indicates the
result of the previous
operation.
N result is negative
V result too big,
causing an overflow
B set by software BRK
command
D in decimal mode
I an interrupt has
occurred
Z result zero
C carry
The flags are tested by
the CPU and, depending
on their state,
determine which part of
the program the CPU will
jump to.
This is how computers
are able to make
decisions.
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