C Language Program for calculator Based on 51 Single-Chip Microcomputer

For the electronic major, although I don't plan to eat this dinner later, I still have to do my homework at the end of the course-"A simple calculator program ". Because of the time, I have never been concerned about sorting it out. I will post it here today to share it with you. It is also a bit of memory for my beautiful youth ...... hee hee 1   The program code is as follows:

# Include <reg51.h>
# Define uchar unsigned char
# Define uintUnsigned int
BitNumsem; // mutex semaphores of the frontend and backend operands
BitEqu; // equal sign judgment
BitCLR; // clear the flag
BitAdd; // Add a flag
BitDec; // minus sign
BitMul; // multiplication mark
BitDiv; // remove the flag
BitOP; // arithmetic sign
UcharKeynum; // key value
UintResult; // Calculation Result
UintPrenum, latnum; // The first and last operands of the two operands.
UcharKeypos;
UcharDisled [] = {0xc0, 0xf9, 0xa4, 0xb0, 0x99, // LED digital seven-segment table
                0x92,0x82, 0xf8, 0x80, 0x90 };
UcharNumbufe [] = {0, 0, 0 };
// Sbit P10 = p1 ^ 0;
// Sbit P11 = p1 ^ 1;
// Sbit p12 = p1 ^ 2;
// Sbit P13 = p1 ^ 3;
VoidT0intal (void); // timer 0 initialization program
Void display (void); // display program
Void resultnum (void); // calculation result of the calculator
Void clear (void); // clears the program
Void delay_510 (void); // compile the 510us program with the latency
Void changenum (uchar * P, uchar ncount); // numbufe [] shift Program
Void main (void)
{
  T0intal ();
  While (1)
  {
    If (numsem)
    {
       Prenum = numbufe [3] * 1000 + numbufe [2] * 100 + numbufe [1] * 10 + numbufe [0];
  Numbufe [4] = 0;
   Numsem = 0;
    }
 If (OP)
 {
   If (Prenum! = 0)
   {
      If (numbufe [4] = 0)
   {
   Numsem = 1;
   }
         If (equ)
   {
      If (numbufe [4]! = 0)
   {
      Latnum = numbufe [3] * 1000 + numbufe [2] * 100 + numbufe [1] * 10 + numbufe [0];
    // Disled [] = 0;
    Keypos = 0;
   }
     Resultnum (); // calculator Result Calculation
           // Display (); // display the calculation result
   }
   
   }
   Else clear ();
 
 }
   If (CLR)
 {
  Clear ();
   }
 Display (); // display the computing result
  }

}
VoidT0intal (void)
{
  Tmod = 0x01;
  Th0 = (65536-20000)/256;
  Tl0 = (65536-20000) % 256;
  Ea = 1;
  Et0 = 1;
  Tr0 = 1;
}
Void display (void)
{
  // Uchar one, two, three, four;
  // One = Result/1000;
  P2 = disled [numbufe [3];
  P0 = 0xfe;
  Delay_510 ();
  // Two = (result-one * 1000)/100;
  P2 = disled [numbufe [2];
  P0 = 0xfd;
  Delay_510 ();
  // Three = (result-one * 1000-two * 100)/10;
  P2 = disled [numbufe [1];
  P0 = 0xfb;
  Delay_510 ();
  // Four = (result-one * 1000-two * 100) % 10;
  P2 = disled [numbufe [0];
  P0 = 0xf7;
  Delay_510 ();

}
Void resultnum (void)
{
  If (OP)
  {
    If (ADD)
 {
 Result = Prenum + latnum;
 }
    If (DEC)
 {
 Result = Prenum-latnum;
 }
 If (Mul)
 {
 Result = Prenum * latnum;
 }
 If (Div)
 {
 Result = Prenum/latnum;
 }
  }
  // Return result;
  // Unsigned char
  // Uchar One, Two, Three;
  // One = Result/1000;
  Numbufe [3] = Result/1000;
  Numbufe [2] = (result-numbufe [3] * 1000)/100;
  // Numbufe [2] = two;
  Numbufe [1] = (result-numbufe [3] * 1000-numbufe [2] * 100)/10;
  // Numbufe [1] = three;
  Numbufe [0] = (result-numbufe [3] * 1000-numbufe [2] * 100) % 10;
}
Void clear (void)
{
 // If (clear)
 //{
    Numbufe [0] = 0;
 Numbufe [1] = 0;
 Numbufe [2] = 0;
 Numbufe [3] = 0;
    Prenum = 0;
 Latnum = 0;
 Result = 0;
 Numsem = 0;
 Keypos = 0;
 CLR = 0;
 Equ = 0;
    Add = 0;
 Dec = 0;
 Mul = 0;
 DIV = 0;
 OP = 0;
 //}
}
VoidChangenum (uchar * P, uchar ncount)
{
 If (ncount <4)
 {
   Uchar ncount;
 Ncount = ncount;
 While (ncount> 0)
 {
    * (P + ncount) = * (p + nCount-1 );
 Ncount --;
  }
 }
}
Void delay_510 (void) // The latency is 510 microseconds.
{
# Pragma ASM
 MoV r0, # 7dh
 MoV R1, #02 h
 Tsr1:
 Djnz r0, tsr1
 MoV r0, # 7dh
 Djnz R1, tsr1
# Pragma endasm
}
 
Void time0_isr_int (void)Interrupt 1 // timer 0 interrupt service subroutine
{
  Th0 = (65536-20000)/256;
  Tl0 = (65536-20000) % 256;
  P1 = 0xf0;
  If (P1 & 0xf0 )! = 0xf0)
  {
     Delay_510 ();
  If (P1 & 0xf0 )! = 0xf0)
  {
     P1 = 0xfe;
  If (P1 & 0xf0) = 0xe0) // number key 0
  {
     Keynum = 0;
   Changenum (numbufe, keypos );
   Keypos ++;
   }
  If (P1 & 0xf0) = 0xd0)
  {
  Keynum = 1;
   Changenum (numbufe, keypos );
   Keypos ++;
  }
     If (P1 & 0xf0) = 0xb0)
  {
    Keynum = 2;
    Changenum (numbufe, keypos );
    Keypos ++;
  }
  If (P1 & 0xf0) = 0x70)
  {
  Keynum = 3;
  Changenum (numbufe, keypos );
   Keypos ++;
  }
  P1 = 0xfd;
  If (P1 & 0xf0) = 0xe0)
  {
  Keynum = 4;
   Changenum (numbufe, keypos );
   Keypos ++;
  }
  If (P1 & 0xf0) = 0xd0)
  {
     Keynum = 5;
     Changenum (numbufe, keypos );
   Keypos ++;
  }
     If (P1 & 0xf0) = 0xb0)