commodore.gen.tr

FEATURES {
    STARTADDRESS: default = $0801;
}
SYMBOLS {
    __LOADADDR__:  type = import;
    __EXEHDR__:    type = import;
    __STACKSIZE__: type = weak, value = $0800; # 2k stack
    __HIMEM__:     type = weak, value = $D000;
}
MEMORY {
    ZP:       file = "", define = yes, start = $0002,           size = $001A;
    LOADADDR: file = %O,               start = %S - 2,          size = $0002;
    HEADER:   file = %O, define = yes, start = %S,              size = $000D;
    MAIN:     file = %O, define = yes, start = __HEADER_LAST__, size = __HIMEM__ - __HEADER_LAST__;
    BSS:      file = "",               start = __ONCE_RUN__,    size = __HIMEM__ - __STACKSIZE__ - __ONCE_RUN__;
}
SEGMENTS {
    ZEROPAGE: load = ZP,       type = zp;
    LOADADDR: load = LOADADDR, type = ro;
    EXEHDR:   load = HEADER,   type = ro;
    STARTUP:  load = MAIN,     type = ro;
    LOWCODE:  load = MAIN,     type = ro,  optional = yes;
#   CODE:     load = MAIN,     type = ro;
    CODE:     load = MAIN, start=$4000     type = ro;
    RODATA:   load = MAIN,     type = ro;
    DATA:     load = MAIN,     type = rw;
    INIT:     load = MAIN,     type = rw;
    ONCE:     load = MAIN,     type = ro,  define   = yes;
    BSS:      load = BSS,      type = bss, define   = yes;
}
FEATURES {
    CONDES: type    = constructor,
            label   = __CONSTRUCTOR_TABLE__,
            count   = __CONSTRUCTOR_COUNT__,
            segment = ONCE;
    CONDES: type    = destructor,
            label   = __DESTRUCTOR_TABLE__,
            count   = __DESTRUCTOR_COUNT__,
            segment = RODATA;
    CONDES: type    = interruptor,
            label   = __INTERRUPTOR_TABLE__,
            count   = __INTERRUPTOR_COUNT__,
            segment = RODATA,
            import  = __CALLIRQ__;
}

CODE:     load = MAIN, start=$4000     type = ro;

#include <stdlib.h>

void main()
{
  unsigned char *pScreen = (unsigned char *)0x2000;
  unsigned char *pColor = (unsigned char *)0x0400;
  unsigned int nByte = 0;

  // Switch to bitmap mode
  __asm__("lda #$3b");
  __asm__("sta $d011");
  __asm__("lda #$08");
  __asm__("sta $d016");

  __asm__("lda $d018");
  __asm__("ora #$8");
  __asm__("sta $d018");


  for(nByte =0; nByte < 0x3ff; nByte++)
  	pColor[nByte] = (unsigned char)(0x0f);

  for(nByte = 0; nByte < 0x1fff; nByte++)
    pScreen[nByte] = (unsigned char)(rand() % 256);

  // Wait for space key
  __asm__("_label:      ");
  __asm__("   lda $dc01 ");
  __asm__("   cmp #$ef  ");
  __asm__("   bne _label");

  // Switch back to text mode
  for(nByte =0; nByte < 0x3ff; nByte++)
  	pColor[nByte] = (unsigned char)(0x20);

  __asm__("lda #$1b");
  __asm__("sta $d011");
  __asm__("lda #$8");
  __asm__("sta $d016");

}