--- /dev/null
+<!doctype linuxdoc system>
+
+<article>
+
+<title>Nintendo Entertainment System specific information for cc65
+<author>Ullrich von Bassewitz, <htmlurl url="mailto:uz@cc65.org" name="uz@cc65.org">
+Stefan A. Haubenthal, <htmlurl url="mailto:polluks@sdf.lonestar.org" name="polluks@sdf.lonestar.org">
+<date>2005-07-17
+
+<abstract>
+An overview over the NES runtime system as it is implemented for the
+cc65 C compiler.
+</abstract>
+
+<!-- Table of contents -->
+<toc>
+
+<!-- Begin the document -->
+
+<sect>Overview<p>
+
+This file contains an overview of the NES runtime system as it comes
+with the cc65 C compiler. It describes the memory layout, NES specific header
+files, available drivers, and any pitfalls specific to that platform.
+
+Please note that NES specific functions are just mentioned here, they are
+described in detail in the separate <htmlurl url="funcref.html" name="function
+reference">. Even functions marked as "platform dependent" may be available on
+more than one platform. Please see the function reference for more
+information.
+
+
+<sect>Binary format<p>
+
+The standard binary output format generated by the linker for the NES target
+is a machine language program with an INES cartridge header. It is of course
+possible to change this behaviour by using a modified startup file and linker
+config.
+
+<sect>Memory layout<p>
+
+cc65 generated programs with the default setup run with the I/O area and a
+CHR bank enabled, which gives a usable memory range of $8000 - $FFF3.
+All boot ROM entry points may be called directly without additional code.
+
+Special locations:
+
+<descrip>
+ <tag/Text screen/
+ The text screen is located at VRAM $2000.
+
+ <tag/Stack/
+ The C runtime stack is located at $7FFF and growing downwards.
+
+ <tag/Heap/
+ The C heap is located at the end of the program and grows towards the C
+ runtime stack.
+
+</descrip><p>
+
+
+
+<sect>Platform specific header files<p>
+
+Programs containing NES specific code may use the <tt/nes.h/ header file.
+
+
+<sect1>NES specific functions<p>
+
+<itemize>
+<item>waitvblank
+</itemize>
+
+
+
+<sect1>Hardware access<p>
+
+The following pseudo variables declared in the <tt/nes.inc/ include file do
+allow access to hardware located in the address space.
+
+<descrip>
+
+ <tag><tt/PPU/</tag>
+ The <tt/PPU/ defines allow access to the PPU chip.
+
+ <tag><tt/APU/</tag>
+ The <tt/APU/ defines allow access to the APU chip.
+
+</descrip><p>
+
+
+
+<sect>Loadable drivers<p>
+
+<sect1>Graphics drivers<p>
+
+No graphics drivers are currently available for the NES.
+
+<sect1>Extended memory drivers<p>
+
+No extended memory drivers are currently available for the NES.
+
+
+<sect1>Joystick drivers<p>
+
+A joystick driver for the standard buttons is available, but must be
+statically linked, because no file I/O is available. See the documentation for
+the <htmlurl url="co65.html" name="co65 utility"> for information on how to do
+that.
+
+<sect1>Mouse drivers<p>
+
+No mouse drivers are currently available for the NES.
+
+
+<sect1>RS232 device drivers<p>
+
+No serial drivers are currently available for the NES.
+
+
+
+<sect>Limitations<p>
+
+<sect1>Disk I/O<p>
+
+The existing library for the NES doesn't implement C file
+I/O. There are no hacks for the <tt/read()/ and <tt/write()/ routines.
+
+To be more concrete, this limitation means that you cannot use any of the
+following functions (and a few others):
+
+<itemize>
+<item>fclose
+<item>fopen
+<item>fread
+<item>fprintf
+<item>fputc
+<item>fscanf
+<item>fwrite
+<item>...
+</itemize>
+
+
+
+<sect>Other hints<p>
+
+
+
+<sect>Bugs/Feedback<p>
+
+If you have problems using the library, if you find any bugs, or if you're
+doing something interesting with it, I would be glad to hear from you. Feel
+free to contact me by email (<htmlurl url="mailto:uz@cc65.org"
+name="uz@cc65.org">).
+
+
+
+<sect>License<p>
+
+This software is provided 'as-is', without any expressed or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+<enum>
+<item> The origin of this software must not be misrepresented; you must not
+ claim that you wrote the original software. If you use this software
+ in a product, an acknowledgment in the product documentation would be
+ appreciated but is not required.
+<item> Altered source versions must be plainly marked as such, and must not
+ be misrepresented as being the original software.
+<item> This notice may not be removed or altered from any source
+ distribution.
+</enum>
+
+</article>
+
+
+
projects / cc65 / blobdiff