[stella] Brick wall ahead

Subject: [stella] Brick wall ahead
From: Pete Holland <petehollandjr@xxxxxxxxx>
Date: Sun, 24 Oct 1999 10:53:12 -0700 (PDT)
I'm slowly but surely programming, but I need some
help.  Specifically, a branch for zero.  I'm need the
computer to comare a number in RAM with zero and
branch if is 0, otherwise just keep steamrolling
ahead.  Now, the questions:

1) How do I control the zero flag?  I see CLC (CLear
Carry), CLD (CLear Decimal), CLI (CLear Interupt), and
CLV (CLear oVerflow), but nothing like a CLZ (CLear
Zero).  Is there a command to do it and it's just not
listed in this book?  Or do I pull the byte for the
flags into A, AND it to turn off the zero flag bit,
and STA it back in RAM?

2) Is this how I'm supposed to do this:
Somehow clear the zero flag
LDA the number I want to compare into A, do whatever
it is I need to with it there.
CMP #$0
BEQ to the end of where the commands for no-zero are
(no more that 127 bytes)
Clear zero flag, do next comparison, etc.

Any help will be appreciated.  This is taking longer
than I expected.


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