Re: [stella] Ruffin Bailey's Disassembly of missile.bin

Subject: Re: [stella] Ruffin Bailey's Disassembly of missile.bin
From: Chris Wilkson <ecwilkso@xxxxxxx>
Date: Mon, 24 Jun 2002 22:17:25 -0400 (EDT)
On Mon, 24 Jun 2002, Ruffin Bailey wrote:

> Here are my guesses for what's going on:
> If you want to load zero into Y, you'll need to have this line:
>         LDY    #$00
> There's an outside chance that you left off the $ before the 00.  If you
> leave out the "#", it'll read from address 00 (does that even exist?).
> Leaving out the $ -- I'm not sure what that does.  :^)  I just tried

The "#" tells the assembler than the operand is an actual piece of data,
not an address.  This is the "immediate" addressing mode.  The "$" tells
the assembler that the operand is a hexadecimal value.  Leaving it out
tells the assembler that is is a decimal value.  So in the case of 0-9,
they are the same with or without the "$".  But things get crazy if you
type "#80" (meaning 80 hex = 128 decimal) and the compiler assumes
80 decimal.  The default varies of course with the assembler used, but
you get the idea.


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