1 <!doctype linuxdoc system>
5 <title>cc65 Library Overview
6 <author>Ullrich von Bassewitz, <htmlurl url="mailto:uz@cc65.org" name="uz@cc65.org">
7 <date>2000-12-02, 2002-11-26
10 An overview over the runtime and C libraries that come with the cc65 compiler,
11 including a discussion of the differences to the ISO standard.
14 <!-- Table of contents -->
17 <!-- Begin the document -->
21 This file contains a short overview of the libraries available for the cc65 C
22 compiler. Please have a look at the <htmlurl url="funcref.html" name="function
23 reference"> for a list function by function. Since the function reference is
24 not complete (I'm working on that) it may happen that you don't find a
25 specific function. In this case, have a look into the header files. All
26 functions, that are not defined by the ISO C standard have a short comment in
27 the headers, explaining their use.
31 <sect>ISO C compatible library<p>
33 The C library contains a large subset of the ISO C library. Functions are
34 usually missing in areas, where there is no support on typical 6502 systems.
35 Wide character sets are an example for this.
37 I will not go into detail about the ISO functions. If a function is not
38 mentioned here explicitly, expect it to be available and to behave as defined
41 Functions that are <em/not/ available:
44 <item><tt>tmpfile/tmpnam</tt>
48 <item>All functions that handle floating point numbers in some manner.
50 <item>The <tt/ldiv/ function (cc65 is currently not able to return structs
51 with a size not equal to 1, 2 or 4 bytes by value).
53 <item>All functions handling wide character strings.
55 <item>Signals and all related functions (having <tt/SIGSEGV/ would be
58 <item><tt>setbuf/setvbuf</tt>
61 Functions not available on all supported systems:
64 <item><tt>fopen/fread/fwrite/fclose/fputs/fgets/fscanf</tt>: The functions
65 are built on open/read/write/close. These latter functions are not available
68 <item><tt>ftell/fseek/fgetpos/fsetpos</tt>: Support depends on the
69 capabilities of the target machine.
71 <item><tt>rename/remove/rewind</tt>: Support depends on the capabilities of
74 <item><tt>time</tt>: Since many of the supported systems do not have a real
75 time clock, which means that the <tt/time/ function is not available. Please
76 note that the other functions from <tt/time.h/ <em/are/ available.
80 Functions that are limited in any way:
83 <item><tt>strcspn/strpbrk/strspn</tt>: These functions have a length
84 limitation of 256 for the second string argument. Since this string gives a
85 character set, and there are only 256 distinct characters, this shouldn't be
88 <item><tt>getenv</tt>: Since there is no such thing as an environment on all
89 supported systems, the <tt/getenv/ function will always return a <tt/NULL/
92 <item><tt>locale</tt>: There is no other locale than the "C" locale. The
93 native locale is identical to the "C" locale.
97 In addition to these limitations, some more functions are limited if inlined
98 versions are requested by using -Os:
101 <item>The <tt/strlen/ function only works for strings with a maximum length
104 <item>The <tt/isxxx/ character classification functions from
105 <tt/<ctype.h>/ will give unpredictable results if the argument is not
106 in character range (0..255). This limitation may be removed by #undef'ing
107 the function name (when using <tt/-Os/, the functions are actually macros
108 that expand to inline assembler code, but the real functions are still
109 available if the macro definition is removed).
114 <sect>CPU specific stuff - 6502.h<p>
116 The header file 6502.h contains some functions that make only sense with the
117 6502 CPU. Examples are macros to insert more or less useful instructions into
118 your C code, or a function to call arbitrary machine language subroutines,
119 passing registers in and out.
123 <sect>Target specific stuff<p>
125 For each supported system there's a header file that contains calls or defines
126 specific for this system. So, when programming for the C64, include c64.h, for
127 the C128, include c128.h and so on. To make the task for the Commodore systems
128 easier, there is also a header file named cbm.h that will define stuff common
129 for all CBM systems, and include the header file for the specific target
132 The header files contain
136 <item>Defines for special keys (like function keys)
138 <item>Defines for special characters (like the graphics characters)
140 <item>Variables with a fixed address in memory that may be used to access
141 special hardware. For the C64 and C128 there is a variable struct named
142 <tt/SID/. Writing to the fields of this struct will write to the SID device
143 instead. Using these variables will make your program more readable and more
144 portable. Don't fear ineffective code when using these variables, the
145 compiler will translate reads and writes to these structs into direct memory
148 <item>Other routines that make only sense for a specific system. One example
149 are routines to write memory locations in the system bank for the CBM PET-II
155 <sect>Direct console I/O - <tt/conio.h/<p>
157 The <tt/conio.h/ header file contains a large set of functions that do screen
158 and keyboard I/O. The functions will write directly to the screen or poll the
159 keyboard directly with no more help from the operating system than needed.
160 This has some disadvantages, but on the other side it's fast and reasonably
161 portable. conio implementations exist for the following targets:
168 <item>c16 (works also for the c116 with up to 32K memory)
171 <item>plus4 (or expanded c16/c116)
172 <item>cbm510 (40 column video)
173 <item>cbm610 (all CBM series-II computers with 80 column video)
177 <item>pet (all CBM PET systems except the 2001)
181 The conio.h header file does also include the system specific header files
182 which define constants for special characters and keys.
186 <sect>Using the joystick - <tt/joystick.h/<p>
188 For systems that have a joystick, <tt/joystick.h/ will define a subroutine to
189 read the current value, including constants to evaluate the result of this
190 function. To help in writing portable code, the header file will define the
191 symbol <tt/__JOYSTICK__/ on systems that have a joystick.
195 <sect>Using a mouse - <tt/mouse.h/<p>
197 Some target machines support a mouse. Mouse support is currently available for
198 the following targets:
209 The available functions are declared in <tt/mouse.h/ To help writing portable
210 code, the header file will define the symbol <tt/__MOUSE__/ in systems that
214 <sect>Bugs/Feedback<p>
216 If you have problems using the library, if you find any bugs, or if you're
217 doing something interesting with it, I would be glad to hear from you. Feel
218 free to contact me by email (<htmlurl url="mailto:uz@cc65.org"
219 name="uz@cc65.org">).
225 This C runtime library implementation for the cc65 compiler is (C)
226 Copyright 1998-2002 Ullrich von Bassewitz. For usage of the binaries
227 and/or sources the following conditions do apply:
229 This software is provided 'as-is', without any expressed or implied
230 warranty. In no event will the authors be held liable for any damages
231 arising from the use of this software.
233 Permission is granted to anyone to use this software for any purpose,
234 including commercial applications, and to alter it and redistribute it
235 freely, subject to the following restrictions:
238 <item> The origin of this software must not be misrepresented; you must not
239 claim that you wrote the original software. If you use this software
240 in a product, an acknowledgment in the product documentation would be
241 appreciated but is not required.
242 <item> Altered source versions must be plainly marked as such, and must not
243 be misrepresented as being the original software.
244 <item> This notice may not be removed or altered from any source