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by Oliver Schmidt. git-svn-id: svn://svn.cc65.org/cc65/trunk@3666 b7a2c559-68d2-44c3-8de9-860c34a00d81
240 lines
6.6 KiB
Plaintext
240 lines
6.6 KiB
Plaintext
<!doctype linuxdoc system>
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<article>
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<title>Apple ][ specific information for cc65
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<author>Ullrich von Bassewitz, <htmlurl url="mailto:uz@cc65.org" name="uz@cc65.org">
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<date>2003-12-16
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<abstract>
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An overview over the Apple ][ runtime system as it is
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implemented for the cc65 C compiler.
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</abstract>
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<!-- Table of contents -->
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<toc>
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<!-- Begin the document -->
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<sect>Overview<p>
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This file contains an overview of the Apple ][ runtime system
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as it comes with the cc65 C compiler. It describes the memory layout,
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Apple ][ specific header files, available drivers, and any
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pitfalls specific to that platform.
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Please note that Apple ][ specific functions are just mentioned
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here, they are described in detail in the separate <htmlurl url="funcref.html"
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name="function reference">. Even functions marked as "platform dependent" may
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be available on more than one platform. Please see the function reference for
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more information.
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<sect>Binary format<p>
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The standard binary output format generated by the linker for the
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Apple ][ target is a machine language program with a 4 byte DOS
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3.3 header. The standard load address is $800.
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The DOS header is in its own segment named <tt/EXEHDR/. If you don't want the
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header for some reason, you can change
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<verb>
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HEADER: start = $0000, size = $4, file = %O;
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</verb>
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to
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<verb>
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HEADER: start = $0000, size = $4, file = "";
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</verb>
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in the linker configuration to have the linker remove it.
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Please note that there is a "Apple ][ ProDOS 8 system program
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for loading binary programs" available in the cc65 User Contributions section.
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It adds all benefits of a ProDOS 8 system program to the standard binary
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program generated by the linker for the Apple ][ target.
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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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$800 to $95FF, so 35.5K of memory are available. ROM calls are
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possible without further precautions.
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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 HIMEM and grows downwards, regardless of
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how your linker config file is setup.
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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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runtime stack.
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</descrip><p>
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<sect>Platform specific header files<p>
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Programs containing Apple ][ specific code may use the
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<tt/apple2.h/ header file.
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<sect1>Apple ][ specific functions<p>
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The functions listed below are special for the Apple ][. See
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the <htmlurl url="funcref.html" name="function reference"> for declaration and
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usage.
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<itemize>
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<item>_dos_type
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<item>get_ostype
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</itemize>
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<sect1>Hardware access<p>
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There's currently no support for direct hardware access. This does not mean
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you cannot do it, it just means that there's no help.
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<sect>Loadable drivers<p>
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<sect1>Graphics drivers<p>
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<descrip>
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<tag><tt/a2.lo.tgi/</tag>
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This driver was written by Stefan Haubenthal. It features a resolution of
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40×40 with 16 colors. At the bottom of the screen, 4 additional text
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lines are available.
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<tag><tt/a2.hi.tgi/</tag>
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This driver was written by Stefan Haubenthal. It features a resolution of
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280×192 with 6 colors. Note that programs using this driver will have
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to be linked with <tt/--start-addr $4000/ to reserve the first hires page.
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</descrip><p>
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<sect1>Extended memory drivers<p>
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<descrip>
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<tag><tt/a2.lc.emd/</tag>
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Gives access to 12KB RAM (48 pages of 256 bytes each) on the
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Apple2 language card. The driver was contributed by Stefan Haubenthal.
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Note that this driver is incompatible with any DOS using the language
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card memory!
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</descrip><p>
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<sect1>Joystick drivers<p>
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<descrip>
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<tag><tt/a2.stdjoy.joy/</tag>
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Supports up to two standard analog joysticks connected to the game port of
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the Apple ][.
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</descrip><p>
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<sect1>Mouse drivers<p>
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Currently no drivers available (in fact, the API for loadable mouse drivers
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does not exist).
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<sect1>RS232 device drivers<p>
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<descrip>
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<tag><tt/a2.ssc.ser/</tag>
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Driver for the Apple2 Super Serial Card. Supports up to 19200 baud,
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hardware flow control (RTS/CTS) and interrupt driven receives. Note
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that because of the peculiarities of the 6551 chip transmits are not
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interrupt driven, and the transceiver blocks if the receiver asserts
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flow control because of a full buffer.
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</descrip><p>
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<sect>Limitations<p>
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<sect>Other hints<p>
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<sect1>Passing arguments to the program<p>
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Command line arguments can be passed to <tt/main()/ after BLOAD. Since this is not
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supported by BASIC, the following syntax was chosen:
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<tscreen><verb>
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]CALL2048:REM ARG1 " ARG2 IS QUOTED" ARG3 "" ARG5
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</verb></tscreen>
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<enum>
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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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a quoted argument are allowed.
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<item>The first argument passed to <tt/main/ is the program name.
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<item>A maximum number of 10 arguments (including the program name) are
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supported.
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</enum>
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<sect1>Interrupts<p>
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The runtime for the Apple ][ uses routines marked as <tt/.CONDES/
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type 2 for ProDOS interrupt handlers. Such routines must be written as simple
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machine language subroutines and will be called automatically by the interrupt
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handler code when they are linked into a program. See the discussion of the
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<tt/.CONDES/ feature in the <htmlurl url="ca65.html" name="assembler manual">.
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<sect>Bugs/Feedback<p>
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If you have problems using the library, if you find any bugs, or if you're
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doing something interesting with it, I would be glad to hear from you. Feel
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free to contact me by email (<htmlurl url="mailto:uz@cc65.org"
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name="uz@cc65.org">).
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<sect>License<p>
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This software is provided 'as-is', without any expressed or implied
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warranty. In no event will the authors be held liable for any damages
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arising from the use of this software.
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Permission is granted to anyone to use this software for any purpose,
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including commercial applications, and to alter it and redistribute it
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freely, subject to the following restrictions:
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<enum>
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<item> The origin of this software must not be misrepresented; you must not
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claim that you wrote the original software. If you use this software
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in a product, an acknowledgment in the product documentation would be
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appreciated but is not required.
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<item> Altered source versions must be plainly marked as such, and must not
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be misrepresented as being the original software.
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<item> This notice may not be removed or altered from any source
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distribution.
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</enum>
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</article>
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