Dot Matrix X 74HC595

Dot Matrix drive by two 74HC595

int latchpin = 8; // connect to pin 12 on the '595
int clockpin = 13; // connect to pin 11 on the '595
int datapin = 11; // connect to pin 14 on the '595
int matrixrow[8] = {1,2,4,8,16,32,64,128};
int matrixcolumn[8] = {1,2,4,8,16,32,64,128};

void pixeldisplay(int row, int column, int holdtime) // turns on and off a pixel at row, column - with delay 'holdtime'
{
 digitalWrite(latchpin, LOW);
 shiftOut(datapin, clockpin, MSBFIRST, matrixcolumn[column-1]); // sets the digit to address
 shiftOut(datapin, clockpin, MSBFIRST, matrixrow[row-1]); // clears the digit
 digitalWrite(latchpin, HIGH);
 delay(holdtime);
}
void rowdisplay(int row, int holdtime)// turns on and off a row of LEDs with delay 'holdtime'
{
 digitalWrite(latchpin, LOW);
 shiftOut(datapin, clockpin, MSBFIRST, 255); // we want all the cathodes on, which is 11111111 in binary, 255 decimal
 shiftOut(datapin, clockpin, MSBFIRST, matrixrow[row-1]); // clears the digit
 digitalWrite(latchpin, HIGH);
 delay(holdtime);
} 
void columndisplay(int column, int holdtime)
// turns on and off a column of LEDs with delay 'holdtime'
{
 digitalWrite(latchpin, LOW);
 shiftOut(datapin, clockpin, MSBFIRST, matrixcolumn[column-1]); 
 shiftOut(datapin, clockpin, MSBFIRST, 255); // we want all the anodes on, which is 11111111 in binary, 255 decimal
 digitalWrite(latchpin, HIGH);
 delay(holdtime);
} 
void setup()
{
 pinMode(latchpin, OUTPUT);
 pinMode(clockpin, OUTPUT);
 pinMode(datapin, OUTPUT);
}
void loop()
{
 for (int a=1; a<9; a++)
 {
 for (int b=1; b<9; b++)
 {
 pixeldisplay(a,b,50);
 }
 }
 for (int a=1; a<9; a++)
 {
 for (int b=1; b<9; b++)
 {
 pixeldisplay(b,a,50);
 }
  }
 for (int zz=1; zz<11; zz++)
 {
 for (int a=1; a<9; a++)
 {
 rowdisplay(a, 50);
 }
 for (int a=1; a<9; a++)
 {
 columndisplay(a, 50);
 }
 }
}