* Changed the way that Atmos programs are started.
- Put a BASIC-language stub at the beginning. - Removed the Autostart flag. Those changes make it easy to give command-line arguments to a program. * Made the Atmos configure file accept a special symbol definition on ld65's command line. We can use "__RAMEND__" to increase the amount of RAM that's available to programs.
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@@ -7,7 +7,7 @@
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<url url="mailto:uz@cc65.org" name="Ullrich von Bassewitz">,<newline>
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<url url="mailto:polluks@sdf.lonestar.org" name="Stefan A. Haubenthal">,<newline>
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<url url="mailto:greg.king5@verizon.net" name="Greg King">
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<date>2014-03-27
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<date>2014-09-23
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<abstract>
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An overview over the Atmos runtime system as it is implemented for the cc65 C
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@@ -32,27 +32,37 @@ more than one platform. Please see the function reference for more
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information.
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<sect>Binary format<p>
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The standard binary output format generated by the linker for the Atmos target
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is a machine language program with a 17 byte tape header including a cc65 tag.
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The standard load and autostart address is $500.
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is a machine language program with a one-line BASIC stub that jumps to the
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machine-language part through <tt/CALL/. It has a 24-byte tape header.
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It means that a file can be loaded as a BASIC program, and started with RUN.
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The standard load address is $501.
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<sect>Memory layout<p>
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In the standard setup, cc65 generated programs use the memory from
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$500 to $9800, so nearly 37K of memory (including the stack) is
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In the standard setup, cc65-generated programs use the memory from
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$0501 to $9800; so, nearly 37K of memory (including the stack) is
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available. ROM calls are possible without further precautions.
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If your program needs more memory, and it won't use TGI graphics, then you can
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use the ld65 command-line option, <tt/-D __RAMEND__=$B400/, when building the
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program, to "grab" the graphics screen RAM. Then, nearly 44K of memory is
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available.
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Special locations:
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<descrip>
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<tag/Stack/
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The C runtime stack is located at $97FF and growing downwards.
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The C runtime stack is located at $97FF (or $B3FF), and grows
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downwards.
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<tag/Heap/
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The C heap is located at the end of the program and grows towards the C
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The C heap is located at the end of the program, and grows towards the C
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runtime stack.
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</descrip><p>
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@@ -117,7 +127,8 @@ The names in the parentheses denote the symbols to be used for static linking of
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<sect1>Graphics drivers<p>
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The default drivers, <tt/tgi_stddrv (tgi_static_stddrv)/, point to <tt/atmos-240-200-2.tgi (atmos_240_200_2_tgi)/.
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The default drivers, <tt/tgi_stddrv (tgi_static_stddrv)/,
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point to <tt/atmos-240-200-2.tgi (atmos_240_200_2_tgi)/.
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<descrip>
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@@ -175,13 +186,14 @@ No mouse drivers are currently available for the Atmos.
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<sect1>Disk I/O<p>
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The existing library for the Atmos doesn't implement C file
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I/O. There are hacks for the <tt/read()/ and <tt/write()/ routines in
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place, which will make functions work that read from and write to <tt/stdout/
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(like <tt/printf()/). However, those functions have some shortcomings which
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won't be fixed, because they're going to be replaced anyway.
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The existing library for the Atmos doesn't implement C file I/O. There are
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hacks for the <tt/read()/ and <tt/write()/ routines in place, which will make
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functions work that read from <tt/stdin/ and write to <tt/stdout/ and
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<tt/stderr/ (such as <tt/printf()/). However, those functions have some
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shortcomings which won't be fixed, because they're going to be replaced
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anyway.
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To be more concrete, the limitation means that you cannot use any of the
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To be more concrete, that limitation means that you cannot use any of the
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following functions (and a few others):
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<itemize>
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@@ -202,7 +214,13 @@ following functions (and a few others):
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<sect1>Function keys<p>
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These are defined to be FUNCT + number key.
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They are defined to be FUNCT + a number key.
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<sect1>Capitals Lock<p>
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The "CAPS Lock" mode is turned off while the program is running. The previous
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mode (usually turned on) is restored when the program stops.
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<sect1>Passing arguments to the program<p>
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@@ -211,10 +229,12 @@ Command-line arguments can be passed to <tt/main()/. Since that is not
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supported directly by BASIC, the following syntax was chosen:
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<tscreen><verb>
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CALL#500:REM ARG1 " ARG2 IS QUOTED" ARG3 "" ARG5
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RUN:REM arg1 " ARG2 IS QUOTED" ARG3 "" ARG5
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</verb></tscreen>
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<enum>
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<item>You must turn <tt/CAPS/ lock off (tap CTRL-T) when you want to type
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lower-case arguments.
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<item>Arguments are separated by spaces.
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<item>Arguments may be quoted.
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<item>Leading and trailing spaces around an argument are ignored. Spaces within
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