This file contains an overview of the PCE runtime system as it comes with the cc65 C compiler. It describes the memory layout, PCE-specific header files, available drivers, and any pitfalls specific to that platform.
Please note that PCE-specific functions are just mentioned here; they are described, in detail, in the separate function reference. Even functions marked as "platform dependent" might be available on more than one platform. Please see the function reference for more information.
The binary output file generated by the linker, for the PCE target, is an image, with no header, that has 8K bytes in the wrong place. That file must be post-processed; the 8K at the end must be moved to the front of the image.
On POSIX systems, the dd command and the shell give a convenient way to do
it. Here is an example of their use:
dd if=conio.bin bs=8K skip=3 > conio.pce
dd if=conio.bin bs=8K count=3 >> conio.pce
+--------+--------+--------+--------+
| Bank 1 | Bank 2 | Bank 3 | Bank 0 | <-- "conio.bin"
+--------+--------+--------+--------+
+--------+--------+--------+--------+
| Bank 0 | Bank 1 | Bank 2 | Bank 3 | <-- "conio.pce"
+--------+--------+--------+--------+
.pce file shows the format of the ROM cartridge that is
plugged into a PC-Engine. But, that .bin file shows what programs
actually see when they execute the code in that cartridge.
cc65-generated programs with the default setup run with the memory map that was used by many PC-Engine games:
Special locations:
The text screen is located at Video RAM (VRAM) address $0000; the Font is located at VRAM address $2000.
The C run-time stack is located in system RAM at $3FFF; and, grows downwards.
The Data (initialized variables) and BSS (uninitialized variables) sections are placed one after the other into system RAM at $2200.
The C heap is located after the end of the BSS section; and, extends up to the C run-time stack.
In an 8K ROM cartridge, code and read-only data are located between $E000 and $FFF5 in the System bank.
In a 16K cartridge, code and read-only data are located between $C000 and $FFF5.
In a 32K cartridge, code and read-only data are located between $8000 and $FFF5.
Programs containing PCE-specific code may use the pce.h header file.
The following constants, defined in the pce.inc include file, do
allow access to hardware that is located in the address space.
PSGThe PSG defines allow access to the PSG (Programmable Sound Generator).
VCEThe VCE defines allow access to the VCE chip (Video Color Encoder).
VDCThe VDC defines allow access to the VDC chip (Video Display Controller).
32K of 16-bit words of Video RAM can be accessed only through this chip.
All drivers must be statically linked because no file I/O is available. The names in the parentheses denote the symbols to be used for static linking of the drivers.
No TGI graphics drivers are currently available for the PCE.
No extended memory drivers are currently available for the PCE.
pce-stdjoy.joy (pce_stdjoy)A joystick driver for the standard two-button joypad is available.
Note that the Japanese 6-button pad currently is not supported.
No mouse drivers are currently available for the PCE.
No serial drivers are currently available for the PCE.
The existing library for the PCE doesn't implement C file
I/O. There are no hacks for the read() and write() routines.
To be more concrete, that limitation means that you cannot use any of the following functions (and a few others):
Some useful resources on PCE coding:
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: