mirror of
https://github.com/michaelcmartin/Ophis.git
synced 2024-11-19 18:33:33 +00:00
191 lines
2.9 KiB
HTML
191 lines
2.9 KiB
HTML
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
||
|
|
<HTML
|
||
|
|
><HEAD
|
||
|
|
><TITLE
|
||
|
|
>Advanced Memory Segments</TITLE
|
||
|
|
><META
|
||
|
|
NAME="GENERATOR"
|
||
|
|
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
|
||
|
|
REL="HOME"
|
||
|
|
TITLE="Programming with Ophis"
|
||
|
|
HREF="book1.html"><LINK
|
||
|
|
REL="UP"
|
||
|
|
TITLE="Using the Ophis Assembler"
|
||
|
|
HREF="p50.html"><LINK
|
||
|
|
REL="PREVIOUS"
|
||
|
|
TITLE="Expressions"
|
||
|
|
HREF="c395.html"><LINK
|
||
|
|
REL="NEXT"
|
||
|
|
TITLE="The Solution"
|
||
|
|
HREF="x454.html"></HEAD
|
||
|
|
><BODY
|
||
|
|
CLASS="CHAPTER"
|
||
|
|
BGCOLOR="#FFFFFF"
|
||
|
|
TEXT="#000000"
|
||
|
|
LINK="#0000FF"
|
||
|
|
VLINK="#840084"
|
||
|
|
ALINK="#0000FF"
|
||
|
|
><DIV
|
||
|
|
CLASS="NAVHEADER"
|
||
|
|
><TABLE
|
||
|
|
SUMMARY="Header navigation table"
|
||
|
|
WIDTH="100%"
|
||
|
|
BORDER="0"
|
||
|
|
CELLPADDING="0"
|
||
|
|
CELLSPACING="0"
|
||
|
|
><TR
|
||
|
|
><TH
|
||
|
|
COLSPAN="3"
|
||
|
|
ALIGN="center"
|
||
|
|
>Programming with Ophis</TH
|
||
|
|
></TR
|
||
|
|
><TR
|
||
|
|
><TD
|
||
|
|
WIDTH="10%"
|
||
|
|
ALIGN="left"
|
||
|
|
VALIGN="bottom"
|
||
|
|
><A
|
||
|
|
HREF="c395.html"
|
||
|
|
ACCESSKEY="P"
|
||
|
|
><<< Previous</A
|
||
|
|
></TD
|
||
|
|
><TD
|
||
|
|
WIDTH="80%"
|
||
|
|
ALIGN="center"
|
||
|
|
VALIGN="bottom"
|
||
|
|
></TD
|
||
|
|
><TD
|
||
|
|
WIDTH="10%"
|
||
|
|
ALIGN="right"
|
||
|
|
VALIGN="bottom"
|
||
|
|
><A
|
||
|
|
HREF="x454.html"
|
||
|
|
ACCESSKEY="N"
|
||
|
|
>Next >>></A
|
||
|
|
></TD
|
||
|
|
></TR
|
||
|
|
></TABLE
|
||
|
|
><HR
|
||
|
|
ALIGN="LEFT"
|
||
|
|
WIDTH="100%"></DIV
|
||
|
|
><DIV
|
||
|
|
CLASS="CHAPTER"
|
||
|
|
><H1
|
||
|
|
><A
|
||
|
|
NAME="AEN443"
|
||
|
|
></A
|
||
|
|
>Advanced Memory Segments</H1
|
||
|
|
><P
|
||
|
|
> This is the last section of the Ophis tutorial. By now we've
|
||
|
|
covered the basics of every command in the assembler; in this
|
||
|
|
final installment we show the full capabilities of
|
||
|
|
the <TT
|
||
|
|
CLASS="LITERAL"
|
||
|
|
>.text</TT
|
||
|
|
> and <TT
|
||
|
|
CLASS="LITERAL"
|
||
|
|
>.data</TT
|
||
|
|
> commands
|
||
|
|
as we produce a final set of Commodore 64 header files.
|
||
|
|
</P
|
||
|
|
><DIV
|
||
|
|
CLASS="SECTION"
|
||
|
|
><H1
|
||
|
|
CLASS="SECTION"
|
||
|
|
><A
|
||
|
|
NAME="AEN448"
|
||
|
|
>The Problem</A
|
||
|
|
></H1
|
||
|
|
><P
|
||
|
|
> Our <TT
|
||
|
|
CLASS="LITERAL"
|
||
|
|
>print'str</TT
|
||
|
|
> routine
|
||
|
|
in <A
|
||
|
|
HREF="x1014.html"
|
||
|
|
><I
|
||
|
|
><I
|
||
|
|
>hello6.oph</I
|
||
|
|
></I
|
||
|
|
></A
|
||
|
|
> accesses
|
||
|
|
memory locations $10 and $11 directly. We'd prefer to have
|
||
|
|
symbolic names for them. This reprises our concerns back in
|
||
|
|
<A
|
||
|
|
HREF="c353.html"
|
||
|
|
>the Chapter called <I
|
||
|
|
>Local variables and memory segments</I
|
||
|
|
></A
|
||
|
|
> when we concluded that we wanted two
|
||
|
|
separate program counters. Now we realize that we really need
|
||
|
|
three; one for the text, one for the data, and one for the zero
|
||
|
|
page data. And if we're going to allow three, we really should
|
||
|
|
allow any number.
|
||
|
|
</P
|
||
|
|
></DIV
|
||
|
|
></DIV
|
||
|
|
><DIV
|
||
|
|
CLASS="NAVFOOTER"
|
||
|
|
><HR
|
||
|
|
ALIGN="LEFT"
|
||
|
|
WIDTH="100%"><TABLE
|
||
|
|
SUMMARY="Footer navigation table"
|
||
|
|
WIDTH="100%"
|
||
|
|
BORDER="0"
|
||
|
|
CELLPADDING="0"
|
||
|
|
CELLSPACING="0"
|
||
|
|
><TR
|
||
|
|
><TD
|
||
|
|
WIDTH="33%"
|
||
|
|
ALIGN="left"
|
||
|
|
VALIGN="top"
|
||
|
|
><A
|
||
|
|
HREF="c395.html"
|
||
|
|
ACCESSKEY="P"
|
||
|
|
><<< Previous</A
|
||
|
|
></TD
|
||
|
|
><TD
|
||
|
|
WIDTH="34%"
|
||
|
|
ALIGN="center"
|
||
|
|
VALIGN="top"
|
||
|
|
><A
|
||
|
|
HREF="book1.html"
|
||
|
|
ACCESSKEY="H"
|
||
|
|
>Home</A
|
||
|
|
></TD
|
||
|
|
><TD
|
||
|
|
WIDTH="33%"
|
||
|
|
ALIGN="right"
|
||
|
|
VALIGN="top"
|
||
|
|
><A
|
||
|
|
HREF="x454.html"
|
||
|
|
ACCESSKEY="N"
|
||
|
|
>Next >>></A
|
||
|
|
></TD
|
||
|
|
></TR
|
||
|
|
><TR
|
||
|
|
><TD
|
||
|
|
WIDTH="33%"
|
||
|
|
ALIGN="left"
|
||
|
|
VALIGN="top"
|
||
|
|
>Expressions</TD
|
||
|
|
><TD
|
||
|
|
WIDTH="34%"
|
||
|
|
ALIGN="center"
|
||
|
|
VALIGN="top"
|
||
|
|
><A
|
||
|
|
HREF="p50.html"
|
||
|
|
ACCESSKEY="U"
|
||
|
|
>Up</A
|
||
|
|
></TD
|
||
|
|
><TD
|
||
|
|
WIDTH="33%"
|
||
|
|
ALIGN="right"
|
||
|
|
VALIGN="top"
|
||
|
|
>The Solution</TD
|
||
|
|
></TR
|
||
|
|
></TABLE
|
||
|
|
></DIV
|
||
|
|
></BODY
|
||
|
|
></HTML
|
||
|
|
>
|