1. Introduction

Welcome to the Calypsi C compiler tool chain for the 6502. This guide provides reference information to help you optimize your use of the compiler toolchain suite. It also offers coding technique suggestions and insights into design and implementation choices made for this C compiler.

1.1. Using this guide

This guide is aimed for those programming the 6502 and provides in depth reference information on how to use the the Calypsi C compiler tool chain.

You should have a working knowledge of:

• The 6502 architecture

• The C programming language

• The operating system of your computer

• The text editor or IDE of your choice

1.2. Copyright notice

Copyright Håkan Thörngren.

This document is under copyright and may not be reproduced without the written consent from Håkan Thörngren.

The Calypsi C compiler tool chain is licensed and must be used according to its terms.

The C library runtime is based on NuttX, which is under the Apache license. The license can be found in "Licenses/C Library License" within the installation directory. Assembly-written runtime parts are covered by the the Calypsi C compiler tool chain license, imposing no royalties or obligations when used with this product.

The Calypsi C compiler tool chain internally uses several open source components. Their licenses are in the "Licenses/Internal component licenses/" directory within the installation directory. These licenses do not impose obligations on any application built with the Calypsi C compiler tool chain.

The 64-bit floating-point library routines are implemented using the Berkeley SoftFloat library. Its license is found in Licenses/Berkeley SoftFloat License in the installation directory. This license applies only when using the long double type or the --64bit-doubles command-line option. It carries the obligation to include its copyright and license with any product that uses the Berkeley SoftFloat library.

Note

The runtime library does not contain any GPL licensed code and does not impose any royalty. Some components as outlined above do carry some obligations, e.g. to mention that they are included in a final product.

1.3. Disclaimer

What is described in this document is subject to change without notice and does not represent any commitments. While what is described in this document is believed to be accurate, Håkan Thörngren takes no responsibility for any errors or omissions.

In no event shall Håkan Thörngren, its employees, its contractors, or the authors of this document be liable for special, direct, indirect, or consequential damage, losses, costs, charges, claims, demands, claim for lost profits, fees, or expenses of any nature or kind.