+
+This file contains an overview of the Atari 7800 runtime system as it
+comes with the cc65 C compiler. It describes the memory layout, Atari
+7800 specific header files and any pitfalls specific to that platform.
+
+
+
+The default binary output format generated by the linker for the Atari
+7800 target is a 48K cartridge image.
+
+
+
+There is lots of different cart hardware available for the atari7800.
+Some carts have ROM, RAM, sound hardware, non-volatile high score chips.
+In order to know what kind of hardware the cart build requires there is
+a header file of 128 bytes in front of the binary.
+
+The default build creates a cart file for a 48K rom cart without any
+extra features like the pokey audio chip or extra RAM.
+
+In order to make cc65 more user friendly the build will add the a78
+header automatically. This allows you to run the binary on emulators
+and flash carts on the real console.
+
+
+
+In order to boot the game in a mode that supports atari7800 functions
+the cart must be encrypted after the linking phase.
+There is a program called sign7800 that can be used to sign the cart.
+The encryption is not required for running the cart on emulators.
+You can also run atari2600 games without encryption.
+
+
+
+cc65 generated programs with the default setup can use RAM from
+from $1800 to $203f.
+The 4k RAM is then mapped to zero page area.
+$2040 to $20ff is visible as zero page.
+After that we have a vero small RAM area that is unused.
+$2100 to $213f.
+Then we mirror a second block from the RAM to become the hardware stack.
+This would be from $2140 to $21ff.
+
+The C-stack starts at $2800 and it can grow down to $2200.
+
+size of the system stack can be customized by defining the
+__STACKSIZE__ linker variable.
+
+Special locations:
+
+
+
+
+
+When powered-up, the Atari 7800 TIA registers contain random
+values. During the initialization phase, the start-up code needs to
+initialize the TIA registers to sound values (or else the console has
+an unpredictable behavior). In this implementation, zeros are written
+to all of TIA registers during the start-up phase.
+
+Note that RIOT registers (mostly timers) are left uninitialized, as
+they don't have any consequence on the console behavior.
+
+
+
+Programs containing Atari 7800 specific code may use the
+
+
+
+
+
+
+
+There are no drivers for the Atari 7800.
+
+
+
+
+TBD
+
+
+
+
+One may write a custom linker configuration file to tune the memory
+layout of a program. See the License
+
+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:
+
+