184 lines
2.8 KiB
HTML
184 lines
2.8 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/loose.dtd">
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<HTML
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><HEAD
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><TITLE
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>Advanced Memory Segments</TITLE
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><META
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NAME="GENERATOR"
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CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
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REL="HOME"
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TITLE="Programming with Ophis"
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HREF="book1.html"><LINK
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REL="PREVIOUS"
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TITLE="Expressions"
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HREF="c371.html"><LINK
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REL="NEXT"
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TITLE="The Solution"
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HREF="x430.html"></HEAD
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><BODY
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CLASS="CHAPTER"
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BGCOLOR="#FFFFFF"
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TEXT="#000000"
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VLINK="#840084"
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><TR
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><TH
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COLSPAN="3"
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ALIGN="center"
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>Programming with Ophis</TH
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></TR
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><TR
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><TD
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WIDTH="10%"
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ALIGN="left"
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WIDTH="10%"
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ALIGN="LEFT"
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WIDTH="100%"></DIV
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><DIV
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CLASS="CHAPTER"
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><H1
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><A
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NAME="AEN419"
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></A
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>Advanced Memory Segments</H1
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><P
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> This is the last section of the Ophis tutorial. By now we've
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covered the basics of every command in the assembler; in this
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final installment we show the full capabilities of
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the <TT
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CLASS="LITERAL"
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>.text</TT
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> and <TT
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CLASS="LITERAL"
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>.data</TT
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> commands
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as we produce a final set of Commodore 64 header files.
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</P
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><DIV
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CLASS="SECTION"
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><H1
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CLASS="SECTION"
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><A
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NAME="AEN424"
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>The Problem</A
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></H1
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><P
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> Our <TT
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CLASS="LITERAL"
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>print'str</TT
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> routine
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in <A
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HREF="x493.html"
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><I
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><I
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>tutor6.oph</I
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></I
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></A
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> accesses
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memory locations $10 and $11 directly. We'd prefer to have
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symbolic names for them. This reprises our concerns back in
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<A
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HREF="c329.html"
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>the Chapter called <I
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>Local variables and memory segments</I
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></A
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> when we concluded that we wanted two
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separate program counters. Now we realize that we really need
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three; one for the text, one for the data, and one for the zero
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page data. And if we're going to allow three, we really should
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allow any number.
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</P
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></DIV
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></DIV
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><TR
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WIDTH="33%"
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VALIGN="top"
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><A
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HREF="c371.html"
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ACCESSKEY="P"
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><<< Previous</A
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></TD
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WIDTH="34%"
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VALIGN="top"
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>Home</A
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HREF="x430.html"
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>Next >>></A
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></TD
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><TR
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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>Expressions</TD
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><TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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> </TD
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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>The Solution</TD
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></TR
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></BODY
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></HTML
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> |