[求助]简单的c语言，但编译不通过

提示内容：

//=====================================================
Build target 'Target 1'
compiling LEDtest2.C...
linking...
*** ERROR L121: IMPROPER FIXUP
    MODULE:  LEDtest2.obj (LEDTEST2)
    SEGMENT: ABSOLUTE
    OFFSET:  000BH
Program Size: data=12.0 xdata=0 code=210
Target not created

编译环境是KEIL 51

源程序

#include<reg51.h>
#define LED P0
#define count 50000
#define TH_M1 (65636-count)/256
#define TL_M1 (65636-count)%256
char bdata mark50;
sbit mark_0=mark50^0;
int intcount=0;

main()
{
 IE=0x82;
 TMOD&=0xf1;
 TMOD|=0x01;
 TH0=TH_M1;
 TL0=TL_M1;
 TR0=1;
 LED=0xf0;
 while(1)
 {
if(mark_0==1)
mark_0=0;
if(++intcount==5)
{
 LED=~LED;
 intcount=0;
 }
  }
 }

//=====================================================
void timer0(void)interrupt 1
{
 TF0=0;
 TH0=TH_M1;
 TL0=TL_M1;
 mark50=0xff;
}