mirror of
https://github.com/cc65/cc65.git
synced 2024-11-18 00:07:21 +00:00
bb9aa7558f
Those tags have two attributes: "url=" and "name=". In the non-HTML output formats, <url> shows both fields, while <htmlurl> shows only the name field (as the HTML format always does.) Thus, the general rules are 1. If the two attributes are different, then use <url>. 2. If they are similar, then use <htmlurl>. 3. If they are the same, then consider using <url> without the "name=" attribute. (The reason for rules 2 and 3 is that the same text shouldn't be shown twice.) There can be exceptions. Example: "od65.sgml" has <htmlurl> because the URL would disturb the flow of a sentence.
538 lines
17 KiB
Plaintext
538 lines
17 KiB
Plaintext
<!doctype linuxdoc system>
|
|
|
|
<article>
|
|
|
|
<title>Enhanced Apple //e specific information for cc65
|
|
<author><url url="mailto:ol.sc@web.de" name="Oliver Schmidt">
|
|
<date>2014-04-10
|
|
|
|
<abstract>
|
|
An overview over the enhanced Apple //e 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 enhanced Apple //e runtime system
|
|
as it comes with the cc65 C compiler. It describes the memory layout,
|
|
enhanced Apple //e specific header files, available drivers, and any
|
|
pitfalls specific to that platform.
|
|
|
|
Please note that enhanced Apple //e 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 file format generated by the linker for the
|
|
enhanced Apple //e target is a binary program with a 4 byte DOS 3.3 header
|
|
containing the load address and load length. The default load address is
|
|
$803.
|
|
|
|
<bf/AppleCommander 1.3.5/ or later (available at <url
|
|
url="http://applecommander.sourceforge.net/">) includes the option <tt/-cc65/
|
|
that allows to put binary files with a DOS 3.3 header onto disk images
|
|
containing DOS 3.3 as well as ProDOS 8.
|
|
|
|
For ProDOS 8 system programs the load address is fixed to $2000 so there
|
|
is no need for a header. Thus the linker configuration
|
|
<ref id="apple-sys-cfg" name="apple2enh-system.cfg"> for those programs
|
|
omits the DOS 3.3 header. The right AppleCommander option to put system files
|
|
without a header on a ProDOS 8 disk image is <tt/-p/.
|
|
|
|
|
|
<sect>Memory layout<p>
|
|
|
|
In the standard setup, cc65 generated programs use the memory from
|
|
$803 to $95FF, so 35.5 KB of RAM are available.
|
|
|
|
Special locations:
|
|
|
|
<descrip>
|
|
|
|
<tag/Stack/
|
|
The C runtime stack is located at HIMEM and grows downwards, regardless of
|
|
how your linker config file is setup.
|
|
|
|
<tag/Heap/
|
|
The C heap is located at the end of the program and grows towards the C
|
|
runtime stack.
|
|
|
|
</descrip><p>
|
|
|
|
While running <tt/main()/ the Language Card bank 2 is enabled for read access.
|
|
However while running module constructors/destructors the Language Card is disabled.
|
|
|
|
Enabling the Language Card allows to use it as additional memory for cc65
|
|
generated code. However code is never automatically placed there. Rather code
|
|
needs to be explicitly placed in the Language Card either per file by compiling
|
|
with <tt/--code-name HIGHCODE/ or per function by enclosing in <tt/#pragma
|
|
code-name (push, "HIGHCODE")/ and <tt/#pragma code-name (pop)/. In either case the
|
|
cc65 runtime system takes care of actually moving the code into the Language
|
|
Card.
|
|
|
|
The amount of memory available in the Language Card for generated code depends
|
|
on the chosen <ref id="link-configs" name="linker configuration">.
|
|
|
|
|
|
|
|
<sect>Linker configurations<label id="link-configs"><p>
|
|
|
|
The ld65 linker comes with a default config file for the enhanced Apple //e,
|
|
which is used via <tt/-t apple2enh/.
|
|
The apple2enh package comes with additional secondary linker config files, which
|
|
are used via <tt/-t apple2enh -C <configfile>/.
|
|
|
|
|
|
<sect1>default config file (<tt/apple2enh.cfg/)<p>
|
|
|
|
Default configuration optimized for a binary program running on ProDOS 8 with
|
|
BASIC.SYSTEM. A plain vanilla ProDOS 8 doesn't actually use the Language Card
|
|
bank 2 memory from $D400 to $DFFF.
|
|
|
|
<descrip>
|
|
|
|
<tag><tt/RAM:/ Main memory area</tag>
|
|
From $803 to $95FF (35.5 KB)
|
|
|
|
<tag><tt/LC:/ Language Card memory area</tag>
|
|
From $D400 to $DFFF (3 KB)
|
|
|
|
<tag><tt/STARTADDRESS:/ Program start address</tag>
|
|
Variable (default: $803)
|
|
|
|
<tag><tt/HEADER:/ Binary file header</tag>
|
|
DOS 3.3 header (address and length)
|
|
|
|
</descrip><p>
|
|
|
|
|
|
<sect1><tt/apple2enh-dos33.cfg/<p>
|
|
|
|
Configuration optimized for a binary program running on DOS 3.3. A plain
|
|
vanilla DOS 3.3 doesn't make use of the Language Card at all.
|
|
|
|
<descrip>
|
|
|
|
<tag><tt/RAM:/ Main memory area</tag>
|
|
From $803 to $95FF (35.5 KB)
|
|
|
|
<tag><tt/LC:/ Language Card memory area</tag>
|
|
From $D000 to $FFFF (12 KB)
|
|
|
|
<tag><tt/STARTADDRESS:/ Program start address</tag>
|
|
Variable (default: $803)
|
|
|
|
<tag><tt/HEADER:/ Binary file header</tag>
|
|
DOS 3.3 header (address and length)
|
|
|
|
</descrip><p>
|
|
|
|
|
|
<sect1><tt/apple2enh-system.cfg/<label id="apple-sys-cfg"><p>
|
|
|
|
Configuration for a system program running on ProDOS 8.
|
|
|
|
<descrip>
|
|
|
|
<tag><tt/RAM:/ Main memory area</tag>
|
|
From $2000 to $BEFF (39.75 KB)
|
|
|
|
<tag><tt/LC:/ Language Card memory area</tag>
|
|
From $D400 to $DFFF (3 KB)
|
|
|
|
<tag><tt/STARTADDRESS:/ Program start address</tag>
|
|
Fixed ($2000)
|
|
|
|
<tag><tt/HEADER:/ Binary file header</tag>
|
|
None
|
|
|
|
</descrip><p>
|
|
|
|
|
|
<sect1><tt/apple2enh-loader.cfg/<label id="apple-load-cfg"><p>
|
|
|
|
Configuration optimized for a binary program running on ProDOS 8 without
|
|
BASIC.SYSTEM. Intended to be used with <bf/LOADER.SYSTEM - an
|
|
Apple ][ ProDOS 8 loader for cc65 programs/, which is available
|
|
in the cc65 User Contributions section.
|
|
|
|
A program loaded by LOADER.SYSTEM works like a ProDOS 8 system program but
|
|
isn't tied to the start address $2000. Thus with the default start
|
|
address $800 the main memory area is increased by 6 KB.
|
|
|
|
<descrip>
|
|
|
|
<tag><tt/RAM:/ Main memory area</tag>
|
|
From $800 to $BEFF (45.75 KB)
|
|
|
|
<tag><tt/LC:/ Language Card memory area</tag>
|
|
From $D400 to $DFFF (3 KB)
|
|
|
|
<tag><tt/STARTADDRESS:/ Program start address</tag>
|
|
Variable (default: $800)
|
|
|
|
<tag><tt/HEADER:/ Binary file header</tag>
|
|
DOS 3.3 header (address and length)
|
|
|
|
</descrip><p>
|
|
|
|
|
|
<sect1><tt/apple2enh-reboot.cfg/<p>
|
|
|
|
Configuration optimized for a binary program running on ProDOS 8 without
|
|
BASIC.SYSTEM. Intended to be used with <bf/LOADER.SYSTEM - an
|
|
Apple ][ ProDOS 8 loader for cc65 programs/ (see above) together
|
|
with the function <tt/rebootafterexit()/.
|
|
|
|
If a ProDOS 8 system program doesn't quit to the ProDOS 8 dispatcher but rather
|
|
reboots the machine after exit then a plain vanilla ProDOS 8 doesn't make use of
|
|
the Language Card bank 2 at all.
|
|
|
|
This setup makes nearly 50 KB available to a cc65 program - on a 64 KB machine!
|
|
|
|
<descrip>
|
|
|
|
<tag><tt/RAM:/ Main memory area</tag>
|
|
From $800 to $BEFF (45.75 KB)
|
|
|
|
<tag><tt/LC:/ Language Card memory area</tag>
|
|
From $D000 to $DFFF (4 KB)
|
|
|
|
<tag><tt/STARTADDRESS:/ Program start address</tag>
|
|
Variable (default: $800)
|
|
|
|
<tag><tt/HEADER:/ Binary file header</tag>
|
|
DOS 3.3 header (address and length)
|
|
|
|
</descrip><p>
|
|
|
|
|
|
|
|
<sect>ProDOS 8 system programs<p>
|
|
|
|
ProDOS 8 system programs are always loaded to the start address $2000.
|
|
For cc65 programs this means that the 6 KB from $800 to $2000 are
|
|
by default unused. There are however several options to make use of that memory
|
|
range.
|
|
|
|
|
|
<sect1>LOADER.SYSTEM<p>
|
|
|
|
The easiest (and for really large programs in fact the only) way to have a cc65
|
|
program use the memory from $800 to $2000 is to link it as binary
|
|
(as opposed to system) program using the linker configuration
|
|
<ref id="apple-load-cfg" name="apple2enh-loader.cfg"> with start address
|
|
$803 and load it with the targetutil LOADER.SYSTEM. The program then works
|
|
like a system program (i.e. quits to the ProDOS dispatcher).
|
|
|
|
Using LOADER.SYSTEM is as simple as copying it to the ProDOS 8 directory of the
|
|
program to load under name <program>.SYSTEM as a system program. For
|
|
example the program <tt/MYPROG/ is loaded by <tt/MYPROG.SYSTEM/.
|
|
|
|
|
|
<sect1>Heap<p>
|
|
|
|
If the cc65 program can be successfully linked as system program using the linker
|
|
configuration <ref id="apple-sys-cfg" name="apple2enh-system.cfg">, but
|
|
uses the heap either explicitly or implicitly (i.e. by loading a driver) then
|
|
the memory from $800 to $2000 can be added to the heap by calling
|
|
<tt/_heapadd ((void *) 0x0800, 0x1800);/ at the beginning of <tt/main()/.
|
|
|
|
|
|
<sect1>ProDOS 8 I/O buffers<p>
|
|
|
|
ProDOS 8 requires for every open file a page-aligned 1 KB I/O buffer. By default
|
|
these buffers are allocated by the cc65 runtime system on the heap using
|
|
<tt/posix_memalign()/. While this is generally the best solution it means quite
|
|
some overhead for (especially rather small) cc65 programs which do open files
|
|
but don't make use of the heap otherwise.
|
|
|
|
The apple2enh package comes with the alternative ProDOS 8 I/O buffer allocation
|
|
module <tt/apple2enh-iobuf-0800.o/ which uses the memory between $800 and
|
|
the program start address for the 1 KB I/O buffers. For system programs (with
|
|
start address $2000) this results in up to 6 I/O buffers and thus up to 6
|
|
concurrently open files.
|
|
|
|
While using <tt/_heapadd()/ as described in the section above together with the
|
|
default I/O buffer allocation basically yields the same placement of I/O buffers
|
|
in memory the primary benefit of <tt/apple2enh-iobuf-0800.o/ is a reduction in code
|
|
size - and thus program file size - of more than 1400 bytes.
|
|
|
|
Using <tt/apple2enh-iobuf-0800.o/ is as simple as placing it on the linker command
|
|
line like this:
|
|
|
|
<tscreen><verb>
|
|
cl65 -t apple2enh -C apple2enh-system.cfg myprog.c apple2enh-iobuf-0800.o
|
|
</verb></tscreen>
|
|
|
|
|
|
|
|
<sect>Platform specific header files<p>
|
|
|
|
Programs containing enhanced Apple //e specific code may use the
|
|
<tt/apple2enh.h/ header file.
|
|
|
|
|
|
<sect1>Enhanced Apple //e specific functions<p>
|
|
|
|
The functions listed below are special for the enhanced Apple //e. See
|
|
the <url url="funcref.html" name="function reference"> for declaration and
|
|
usage.
|
|
|
|
<itemize>
|
|
<item>_auxtype
|
|
<item>_dos_type
|
|
<item>_filetype
|
|
<item>get_ostype
|
|
<item>rebootafterexit
|
|
<item>ser_apple2_slot
|
|
<item>textframe
|
|
<item>textframexy
|
|
<item>tgi_apple2_mix
|
|
<item>videomode
|
|
</itemize>
|
|
|
|
|
|
<sect1>Hardware access<p>
|
|
|
|
There's currently no support for direct hardware access. This does not mean
|
|
you cannot do it, it just means that there's no help.
|
|
|
|
|
|
|
|
<sect>Loadable drivers<p>
|
|
|
|
The names in the parentheses denote the symbols to be used for static linking of the drivers.
|
|
|
|
|
|
<sect1>Graphics drivers<p>
|
|
|
|
<descrip>
|
|
|
|
<tag><tt/a2e.lo.tgi (a2e_lo_tgi)/</tag>
|
|
This driver features a resolution of 40×48 with 16 colors.
|
|
|
|
The function <tt/tgi_apple2_mix()/ allows to activate 4 lines of text. The
|
|
function clears the corresponding area at the bottom of the screen.
|
|
|
|
<tag><tt/a2e.hi.tgi (a2e_hi_tgi)/</tag>
|
|
This driver features a resolution of 280×192 with 8 colors and two
|
|
hires pages. Note that programs using this driver will have to be linked
|
|
with <tt/--start-addr $4000/ to reserve the first hires page or with
|
|
<tt/--start-addr $6000/ to reserve both hires pages.
|
|
|
|
Note that the second hires page is only available if the text display is not in
|
|
80 column mode. This can be asserted by calling <tt/videomode (VIDEOMODE_40COL);/
|
|
before installing the driver.
|
|
|
|
The function <tt/tgi_apple2_mix()/ allows to activate 4 lines of text. The
|
|
function doesn't clear the corresponding area at the bottom of the screen.
|
|
|
|
In memory constrained situations the memory from $803 to $1FFF
|
|
can be made available to a program by calling <tt/_heapadd ((void *) 0x0803, 0x17FD);/
|
|
at the beginning of <tt/main()/. Doing so is beneficial even if the program
|
|
doesn't use the the heap explicitly because loading the driver (and in fact
|
|
already opening the driver file) uses the heap implicitly.
|
|
|
|
</descrip><p>
|
|
|
|
|
|
<sect1>Extended memory drivers<p>
|
|
|
|
<descrip>
|
|
|
|
<tag><tt/a2e.auxmem.emd (a2e_auxmem_emd)/</tag>
|
|
Gives access to 47.5 KB RAM (190 pages of 256 bytes each) on an Extended
|
|
80-Column Text Card.
|
|
|
|
Note that this driver doesn't check for the actual existence of the memory
|
|
and that it doesn't check for ProDOS 8 RAM disk content!
|
|
|
|
</descrip><p>
|
|
|
|
|
|
<sect1>Joystick drivers<p>
|
|
|
|
<descrip>
|
|
|
|
<tag><tt/a2e.stdjoy.joy (a2e_stdjoy_joy)/</tag>
|
|
Supports up to two standard analog joysticks connected to the game port of
|
|
the enhanced Apple //e.
|
|
|
|
</descrip><p>
|
|
|
|
|
|
<sect1>Mouse drivers<p>
|
|
|
|
<descrip>
|
|
|
|
<tag><tt/a2e.stdmou.mou (a2e_stdmou_mou)/</tag>
|
|
Driver for the AppleMouse II Card. Searches all Apple II slots
|
|
for an AppleMouse II Card compatible firmware. The default bounding
|
|
box is [0..279,0..191].
|
|
|
|
Note that the enhanced Apple //e default mouse callbacks support
|
|
text mode only.
|
|
|
|
</descrip><p>
|
|
|
|
|
|
<sect1>RS232 device drivers<p>
|
|
|
|
<descrip>
|
|
|
|
<tag><tt/a2e.ssc.ser (a2e_ssc_ser)/</tag>
|
|
Driver for the Apple II Super Serial Card. Supports up to 19200 baud,
|
|
hardware flow control (RTS/CTS) and interrupt driven receives. Note
|
|
that because of the peculiarities of the 6551 chip transmits are not
|
|
interrupt driven, and the transceiver blocks if the receiver asserts
|
|
flow control because of a full buffer.
|
|
|
|
The driver defaults to slot 2. Call <tt/ser_apple2_slot()/ prior to
|
|
<tt/ser_open()/ in order to select a different slot. <tt/ser_apple2_slot()/
|
|
succeeds for all Apple II slots, but <tt/ser_open()/ fails with
|
|
<tt/SER_ERR_NO_DEVICE/ if there's no SSC firmware found in the selected slot.
|
|
|
|
</descrip><p>
|
|
|
|
|
|
|
|
<sect>Limitations<p>
|
|
|
|
|
|
<sect1>DOS 3.3<p>
|
|
|
|
Although the standard binaries generated by the linker for the enhanced Apple //e
|
|
generally run both on DOS 3.3 (with Applesoft BASIC) and on ProDOS 8 (with
|
|
BASIC.SYSTEM) there are some limitations for DOS 3.3:
|
|
|
|
<descrip>
|
|
|
|
<tag>Disk File I/O</tag>
|
|
There's no disk file I/O support. Any attempt to use it yields an error with
|
|
<tt/errno/ set to <tt/ENOSYS/. This implicitly means that loadable drivers
|
|
are in general not functional as they depend on disk file I/O. Therefore the statically
|
|
linked drivers have to be used instead.
|
|
|
|
<tag/Interrupts/
|
|
There's no <tt/interruptor/ support. Any attempt to use it yields the message
|
|
'Failed to alloc interrupt' on program startup. This implicitly means that
|
|
<tt/a2e.stdmou.mou/ and <tt/a2e.ssc.ser/ are not functional as they depend on
|
|
interrupts.
|
|
|
|
</descrip><p>
|
|
|
|
|
|
<sect1>Direct console I/O<p>
|
|
|
|
<descrip>
|
|
|
|
<tag/Color/
|
|
The enhanced Apple //e has no color text mode. Therefore the functions
|
|
textcolor(), bgcolor() and bordercolor() have no effect.
|
|
|
|
<tag/Cursor/
|
|
The enhanced Apple //e has no hardware cursor. Therefore the function
|
|
cursor() has no effect.
|
|
|
|
</descrip><p>
|
|
|
|
|
|
|
|
<sect>Other hints<p>
|
|
|
|
|
|
<sect1>Passing arguments to the program<p>
|
|
|
|
Command line arguments can be passed to <tt/main()/ after BLOAD. Since this is not
|
|
supported by BASIC, the following syntax was chosen:
|
|
|
|
<tscreen><verb>
|
|
]CALL2051:REM ARG1 " ARG2 IS QUOTED" ARG3 "" ARG5
|
|
</verb></tscreen>
|
|
|
|
<enum>
|
|
<item>Arguments are separated by spaces.
|
|
<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>A maximum number of 10 arguments (including the program name) are
|
|
supported.
|
|
</enum>
|
|
|
|
|
|
<sect1>Function keys<p>
|
|
|
|
These are defined to be OpenApple + number key.
|
|
|
|
|
|
<sect1>Interrupts<p>
|
|
|
|
The runtime for the enhanced Apple //e uses routines marked as
|
|
<tt/.INTERRUPTOR/ for ProDOS 8 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 <url
|
|
url="ca65.html" name="assembler manual">.
|
|
|
|
|
|
<sect1>DIO<p>
|
|
|
|
<descrip>
|
|
|
|
<tag/Drive ID/
|
|
The function <url url="dio.html#s1" name="dio_open()"> has the single
|
|
parameter <tt/device/ to identify the device to be opened. Therefore an
|
|
Apple II slot and drive pair is mapped to that <tt/drive_id/ according
|
|
to the formula
|
|
|
|
<tscreen>
|
|
device = slot + (drive - 1) * 8
|
|
</tscreen>
|
|
|
|
so that for example slot 6 drive 2 is mapped to <tt/device/ 14.
|
|
|
|
<tag/Sector count/
|
|
The function <url url="dio.html#s3" name="dio_query_sectcount()"> returns
|
|
the correct sector count for all ProDOS 8 disks. However for any non-ProDOS 8
|
|
disk it simply always returns 280 (which is only correct for a 140 KB disk).
|
|
This condition is indicated by the <tt/_oserror/ value 82.
|
|
|
|
</descrip><p>
|
|
|
|
|
|
|
|
<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>
|