<!doctype linuxdoc system>
<article>
-
-<title>Commodore 64 specific information for cc65
-<author>Ullrich von Bassewitz, <htmlurl url="mailto:uz@cc65.org" name="uz@cc65.org">
-<date>2003-09-23
+<title>Commodore 64-specific information for cc65
+<author><url url="mailto:uz@cc65.org" name="Ullrich von Bassewitz"><newline>
+<url url="mailto:greg.king5@verizon.net" name="Greg King">
<abstract>
An overview over the C64 runtime system as it is implemented for the cc65 C
<sect>Overview<p>
This file contains an overview of the C64 runtime system as it comes with the
-cc65 C compiler. It describes the memory layout, C64 specific header files,
+cc65 C compiler. It describes the memory layout, C64-specific header files,
available drivers, and any pitfalls specific to that platform.
-Please note that C64 specific functions are just mentioned here, they are
-described in detail in the separate <htmlurl url="funcref.html" name="function
+Please note that C64-specific functions are just mentioned here, they are
+described in detail in the separate <url 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 C64 target
-is a machine language program with a one line BASIC stub. This means that a
-program can be loaded as BASIC program and started with RUN. It is of course
-possible to change this behaviour by using a modified startup file and linker
-config.
+is a machine language program with a one line BASIC stub, which calls the
+machine language part via SYS. This means that a program can be loaded as
+BASIC program and started with RUN. It is of course possible to change this
+behaviour by using a modified startup file and linker config.
<sect>Memory layout<p>
</descrip><p>
+<sect>Linker configurations<p>
+
+The ld65 linker comes with a default config file for the Commodore 64,
+which is used via <tt/-t c64/. The
+c64 package comes with additional secondary linker config files, which are
+used via <tt/-t c64 -C <configfile>/.
+
+
+<sect1>default config file (<tt/c64.cfg/)<p>
+
+The default configuration is tailored to C programs. It supplies the load
+address and a small BASIC stub that starts the compiled program using a SYS
+command.
+
+
+<sect1><tt/c64-asm.cfg/<p>
+
+This configuration is made for assembler programmers who don't need a special
+setup. The default start address is $801. It can be changed with the
+linker command line option <tt/--start-addr/. All standard segments with the
+exception of <tt/zeropage/ are written to the output file and a two byte load
+address is prepended.
+
+To use this config file, assemble with <tt/-t c64/ and link with <tt/-C
+c64-asm.cfg/. The former will make sure that correct character translation is
+in effect, while the latter supplies the actual config. When using <tt/cl65/,
+use both command line options.
+
+Sample command line for <tt/cl65/:
+
+<tscreen><verb>
+cl65 -o file.prg -t c64 -C c64-asm.cfg source.s
+</verb></tscreen>
+
+To generate code that loads to $C000:
+
+<tscreen><verb>
+cl65 -o file.prg --start-addr $C000 -t c64 -C c64-asm.cfg source.s
+</verb></tscreen>
+
+It is also possible to add a small BASIC header to the program, that uses SYS
+to jump to the program entry point (which is the start of the code segment).
+The advantage is that the program can be started using RUN.
+
+To generate a program with a BASIC SYS header, use
+
+<tscreen><verb>
+cl65 -o file.prg -u __EXEHDR__ -t c64 -C c64-asm.cfg source.s
+</verb></tscreen>
+
+Please note that in this case a changed start address doesn't make sense,
+since the program must be loaded to the BASIC start address.
+
+<sect>Extras<p>
+
+<sect1>80 Columns conio driver<p>
+
+The C64 package comes with an alternative software driven 80 columns
+module <tt/c64-soft80.o/ which uses the memory under I/O between $D000
+and $FF3F.
+
+In memory constrained situations the memory from $400 to $7FF
+can be made available to a program by calling <tt/_heapadd ((void *) 0x0400, 0x0400);/
+at the beginning of <tt/main()/. Doing so is beneficial even if the program
+doesn't use the the heap explicitly because loading a driver uses the heap implicitly.
+
+Using <tt/c64-soft80.o/ is as simple as placing it on the linker command
+line like this:
+
+<tscreen><verb>
+cl65 -t c64 myprog.c c64-soft80.o
+</verb></tscreen>
+
+Note that the soft80 conio driver is incompatible with the
+<tt/c64-ram.emd (c64_ram_emd)/ extended memory driver and the
+ <tt/c64-hi.tgi (c64_hi_tgi)/ graphics driver.
-<sect
>Platform specific header files<p>
+<sect
2>80 Columns conio driver (monochrome)<p>
-Programs containing C64 specific code may use the <tt/c64.h/ or <tt/cbm.h/
+In an (even more) memory constrained situation, a size optimized version of the
+software driven 80 columns module may be used, which only supports one common
+text color for the whole screen.
+
+<tscreen><verb>
+cl65 -t c64 myprog.c c64-soft80mono.o
+</verb></tscreen>
+
+<sect>Platform-specific header files<p>
+
+Programs containing C64-specific code may use the <tt/c64.h/ or <tt/cbm.h/
header files. Using the later may be an option when writing code for more than
one CBM platform, since it includes <tt/c64.h/ and declares several functions
common to all CBM platforms.
-<sect1>C64
specific functions<p>
+<sect1>C64
-specific functions<p>
-The functions listed below are special for the C64. See the <htmlurl
+The functions listed below are special for the C64. See the <url
url="funcref.html" name="function reference"> for declaration and usage.
<itemize>
</itemize>
-<sect1>CBM specific functions<p>
+<sect1>C64-specific accelerator functions<p>
+
+The functions listed below are accelerator functions for the C64. See the <url
+url="funcref.html" name="function reference"> for declaration and usage.
+
+<itemize>
+<item>detect_c128
+<item>detect_c64dtv
+<item>detect_c65
+<item>detect_chameleon
+<item>detect_scpu
+<item>detect_turbomaster
+<item>get_c128_speed
+<item>get_c64dtv_speed
+<item>get_c65_speed
+<item>get_chameleon_speed
+<item>get_scpu_speed
+<item>get_turbomaster_speed
+<item>set_c128_speed
+<item>set_c64dtv_speed
+<item>set_c65_speed
+<item>set_chameleon_speed
+<item>set_scpu_speed
+<item>set_turbomaster_speed
+</itemize>
+
+
+<sect1>CBM-specific functions<p>
Some functions are available for all (or at least most) of the Commodore
-machines. See the <htmlurl url="funcref.html" name="function reference"> for
+machines. See the <url url="funcref.html" name="function reference"> for
declaration and usage.
<itemize>
<item>cbm_k_basin
<item>cbm_k_bsout
<item>cbm_k_clrch
+<item>cbm_k_tksa
+<item>cbm_k_second
<item>cbm_load
<item>cbm_open
<item>cbm_opendir
<sect>Loadable drivers<p>
+The names in the parentheses denote the symbols to be used for static linking of the drivers.
+
+
+<label id="graphics-drivers">
<sect1>Graphics drivers<p>
<em>Note:</em> All available graphics drivers for the TGI interface will use
-the space below the I/O area and kernal ROM, so you can have hires graphics in
-the standard setup without any memory loss or need for a changed
-configuration.
+the space below the I/O area and Kernal ROM; so, you can have hires graphics in
+the standard setup without any memory loss or need for a changed configuration.
+
+You can use a mouse driver at the same time that you use a TGI driver. But, if
+you want to see the default mouse pointer on the graphics screen, then you
+explicitly must link a special object file into your program. It will put the
+arrow into the "high RAM" area where the bitmaps are put. Its name is
+"<tt/c64-tgimousedata.o/". Example:
+
+<tscreen><verb>
+cl65 -t c64 -o program-file main-code.c subroutines.s c64-tgimousedata.o
+</verb></tscreen>
<descrip>
- <tag><tt/c64-hi.tgi/</tag>
+ <tag><tt/c64-hi.tgi (c64_hi_tgi)/</tag>
This driver features a resolution of 320*200 with two colors and an
adjustable palette (that means that the two colors can be chosen out of a
palette of the 16 C64 colors).
</descrip><p>
+Note that the graphics drivers are incompatible with the
+<tt/c64-ram.emd (c64_ram_emd)/ extended memory driver and the
+ <tt/c64-soft80.o/ software 80-columns conio driver.
+
<sect1>Extended memory drivers<p>
<descrip>
- <tag><tt/c64-georam.emd/</tag>
- A driver for the GeoRam cartridge. The driver will always assume 2048 pages
- of 256 bytes each. There are no checks, so if your program knows better,
- just go ahead.
+ <tag><tt/c64-65816.emd (c64_65816_emd)/</tag>
+ Extended memory driver for 65816 (eg SCPU) based extra RAM.
+ Written and contributed by Marco van den Heuvel.
+
+ <tag><tt/c64-c256k.emd (c64_c256k_emd)/</tag>
+ A driver for the C64 256K memory expansion. This driver offers 768 pages of
+ 256 bytes each. Written and contributed by Marco van den Heuvel.
+
+ <tag><tt/c64-dqbb.emd (c64_dqbb_emd)/</tag>
+ A driver for the Double Quick Brown Box cartridge. This driver offers
+ 64 pages of 256 bytes each. Written and contributed by Marco van den Heuvel.
- <tag><tt/c64-ram.emd/</tag>
- A driver for the hidden RAM below the I/O area and kernal ROM. Supports 48
+ <tag><tt/c64-georam.emd (c64_georam_emd)/</tag>
+ A driver for the Berkeley Softworks GeoRam cartridge. The driver will
+ determine the available RAM from the connected cartridge. It supports 64KB
+ up to 2048KB of RAM.
+
+ <tag><tt/c64-isepic.emd (c64_isepic_emd)/</tag>
+ A driver for the ISEPIC cartridge. This driver offers just 8 pages of 256
+ bytes each. Written and contributed by Marco van den Heuvel.
+
+ <tag><tt/c64-ram.emd (c64_ram_emd)/</tag>
+ A driver for the hidden RAM below the I/O area and kernal ROM. Supports 47
256 byte pages. Please note that this driver is incompatible with any of the
- graphics drivers!
+ graphics drivers, or the soft80 conio driver!
- <tag><tt/c64-ramcart.emd/</tag>
+ <tag><tt/c64-ramcart.emd (c64_ramcart_emd)/</tag>
A driver for the RamCart 64/128 written and contributed by Maciej Witkowiak.
Will test the hardware for the available RAM.
- <tag><tt/c64-reu.emd/</tag>
- A driver for the CBM REUs. The driver will determine from the connected REU
- if it supports 128KB of RAM or more. In the latter case, 256KB are assumed,
- but since there are no range checks, the application can use more memory if
- it has better knowledge about the hardware than the driver.
+ <tag><tt/c64-reu.emd (c64_reu_emd)/</tag>
+ A driver for the CBM REUs. The driver will test the connected REU to find
+ out how much RAM is present.
- <tag><tt/c64-vdc.emd/</tag>
+ <tag><tt/c64-vdc.emd (c64_vdc_emd)/</tag>
A driver for the VDC memory of the C128. Written and contributed by Maciej
- WitkowiakCan be used if the program is running in C64 mode of the C128.
+ Witkowiak. Can be used if the program is running in C64 mode of the C128.
Autodetects the amount of memory available (16 or 64K) and offers 64 or 256
pages of 256 bytes each.
+ <tag><tt/dtv-himem.emd (dtv_himem_emd)/</tag>
+ A driver for the C64 D2TV (the second or PAL version). This driver offers
+ indeed 7680 pages of 256 bytes each.
+
</descrip><p>
<sect1>Joystick drivers<p>
+The default drivers, <tt/joy_stddrv (joy_static_stddrv)/, point to <tt/c64-stdjoy.joy (c64_stdjoy_joy)/.
+
<descrip>
- <tag><tt/c64-hitjoy.joy/</tag>
- Driver for the Digital Excess & Hitmen adapter contributed by Groepaz. See
- <htmlurl url="http://www.digitalexcess.de/downloads/productions.php"
- name="http://www.digitalexcess.de/downloads/productions.php"> on
+ <tag><tt/c64-hitjoy.joy (c64_hitjoy_joy)/</tag>
+ Driver for the Digital Excess & Hitmen adapter contributed by Groepaz.
+ See <url url="http://www.digitalexcess.de/downloads/productions.php"> on
instructions how to build one. Up to four joysticks are supported.
- <tag><tt/c64-ptvjoy.joy/</tag>
+ <tag><tt/c64-ptvjoy.joy (c64_ptvjoy_joy)/</tag>
Driver for the Protovision 4-player adapter contributed by Groepaz. See
- <htmlurl url="http://www.protovision-online.de/hardw/hardwstart.htm"
- name="http://www.protovision-online.de/hardw/hardwstart.htm"> for prices and
- building instructions. Up to four joysticks are supported.
+ <url url="http://www.protovision-online.de/hardw/4_player.php?language=en"
+ name="Protovision shop"> for prices and building instructions. Up to four
+ joysticks are supported.
- <tag><tt/c64-stdjoy.joy/</tag>
+ <tag><tt/c64-stdjoy.joy (c64_stdjoy_joy)/</tag>
Supports up to two standard joysticks connected to the joysticks port of
the C64.
-</descrip><p>
+ <tag><tt/c64-numpad.joy (c64_numpad_joy)/</tag>
+ Supports one joystick emulated by the numberpad of the C128 in C64 mode,
+ the firebutton is labeled &dquot;5&dquot; and ENTER.
+</descrip><p>
<sect1>Mouse drivers<p>
-Currently no drivers available (in fact, the API for loadable mouse drivers
-does not exist).
+You can use these drivers in text-mode or graphics-mode (TGI) programs. See
+the description of <ref id="graphics-drivers" name="the graphics drivers">.
+
+The default drivers, <tt/mouse_stddrv (mouse_static_stddrv)/, point to <tt/c64-1351.mou (c64_1351_mou)/.
+
+<descrip>
+
+ <tag><tt/c64-1351.mou (c64_1351_mou)/</tag>
+ Supports a standard mouse connected to port #0 of the C64.
+
+ <tag><tt/c64-inkwell.mou (c64_inkwell_mou)/</tag>
+ Supports the Inkwell Systems lightpens, connected to port #0 of the C64.
+ It can read both the one-button 170-C and the two-button 184-C pens. (It can
+ read other lightpens and light-guns that send their button signal to the
+ joystick left-button pin or the paddle Y [up/down] pin.)
+
+ <tag><tt/c64-joy.mou (c64_joy_mou)/</tag>
+ Supports a mouse emulated by a standard joystick, e.g. 1350 mouse, in port
+ #1 of the C64.
+
+ <tag><tt/c64-pot.mou (c64_pot_mou)/</tag>
+ Supports a potentiometer device, e.g. Koala Pad, connected to port #1 of
+ the C64.
+
+</descrip><p>
<sect1>RS232 device drivers<p>
<descrip>
- <tag><tt/c64-swlink.ser/</tag>
- Driver for the SwiftLink cartridge. Supports up to 38400 baud, hardware flow
- control (RTS/CTS) and interrupt driven receives. Note that because of the
- peculiarities of the 6551 chip together with the use of the NMI, transmits
- are not interrupt driven, and the transceiver blocks if the receiver asserts
+ <tag><tt/c64-swlink.ser (c64_swlink_ser)/</tag>
+ Driver for the SwiftLink cartridge. Supports up to 38400 BPS, hardware flow
+ control (RTS/CTS), and interrupt-driven receives. Note that, because of the
+ peculiarities of the 6551 chip, together with the use of the NMI, transmits
+ are not interrupt driven; and, the transceiver blocks if the receiver asserts
flow control because of a full buffer.
</descrip><p>
<sect>Limitations<p>
+<sect1>Realtime clock<p>
+
+The realtime clock functions use the CIA1 TOD clock. As that clock only stores
+the time but not the date, the date set by <tt/clock_settime()/ is simply stored
+inside the C library for retrieval in the same program via <tt/clock_gettime()/.
+
+
<sect>Other hints<p>
+
+<sect1>Escape code<p>
+
+For an Esc, press CTRL and the <tt/[/ key.
+
+
<sect1>Passing arguments to the program<p>
-Command line arguments can be passed to <tt/main()/. Since this is not
-supported by BASIC, the following syntax was chosen:
+Command-line arguments can be passed to <tt/main()/. Since this is not
+supported directly by BASIC, the following syntax was chosen:
<tscreen><verb>
RUN:REM ARG1 " ARG2 IS QUOTED" ARG3 "" ARG5
<item>Arguments may be quoted.
<item>Leading and trailing spaces around an argument are ignored. Spaces within
a quoted argument are allowed.
-<item>The first argument passed to <tt/main/ is the program name.
+<item>The first argument passed to <tt/main()/ is the program name.
<item>A maximum number of 10 arguments (including the program name) are
supported.
</enum>
<sect1>Interrupts<p>
-The runtime for the C64 uses routines marked as <tt/.CONDES/ type 2 for
+The runtime for the C64 uses routines marked as <tt/.INTERRUPTOR/ for
interrupt handlers. Such routines must be written as simple machine language
subroutines and will be called automatically by the interrupt handler code
when they are linked into a program. See the discussion of the <tt/.CONDES/
-feature in the <htmlurl url="ca65.html" name="assembler manual">.
-
-
-
-<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">).
+feature in the <url url="ca65.html" name="assembler manual">.
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.
+<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>
-
-
-
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