Subject: Re: [stella] Zero-Page Memory Addressing.. (Still a newbie, but getting there.) From: Erik Mooney <erik@xxxxxxxxxx> Date: Fri, 02 Nov 2001 10:27:03 -0500 |
11/2/2001 10:13:52 AM, "Joel Park" <joelp@xxxxxxxxxxxxxxxxxx> wrote: >Thank you for the Answers. You totally confirmed any assumptions I may >have had. It really helps to picture Stella as a whole. > >I've got to say that I'm getting excited about this stuff. >I'm a Visual Basic Programmer by profession, it's fantastic to find >something I can do that is so far from programming Visual Basic. Heh, Me Too. I write VB for a living, and Stella is a totally different experience. Give me VB or give me assembler; none of this wussy inbetween stuff like C++. :) >Thanks again for all your help, y'all never let me down. A further note: >> The second half is the famous 128 byte RAM. As you >> already found out, it's ranging from $80 - $FF. >> >> So all RAM access is actually in the zeropage, which >> means there's very fast access here. (Any serious C64 >> coder would sell his grandma for 128 Bytes free zeropage >> RAM, BTW :-)) That RAM is also mirrored (access the same bytes through different addresses) at $180-$1FF. When RAM is accessed via the stack manipulation instructions (PHA/PLA/PHP/PLP/JSR/RET), the 6502 uses the $180-$1FF addresses -- that is, the stack is in page 1. ---------------------------------------------------------------------------------------------- Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/
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