四位七段数码管怎么接三极管做驱动电路啊，还有如何写一个c51程序实现分和秒的动态扫描啊？

第1，用NPN三极管（比如9012）做数码管列输入驱动滑尘
第2，用NPN或者PNP三极管（随你选）简让肢做数拦世码管行输入驱动
第3，#include

#define uint unsigned int

#define uchar unsigned char

sbit _led=P2^7;

sbit key1=P2^0;

sbit key2=P2^1;

sbit key3=P2^2;

uchar num=0,temp=0,count=0;

uchar aa;

uchar hour,min,sec;

uchar code table[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90};

void delay(uint z);

void display(uchar a,uchar b,uchar c,uchar d,uchar e,uchar f,uchar aa);

void read_key();

void led();

void time_change();

/****************** 主函数 *******************/

void main()

{

P2=0xff;

hour=12;

min=0;

sec=0;

TMOD=0x11;

TH0=(65536-50000)/256;

TL0=(65536-50000)%256;

TH1=(65536-50000)/256;

TL1=(65536-50000)%256;

EA=1;

ET0=1;

ET1=1;

TR0=1;

TR1=1;

aa=0xff;

while(1)

{

time_change();

display(table[hour/10],table[hour%10],table[min/10],

table[min%10],table[sec/10],table[sec%10],0xff);

}

}