74HC595 7‑segment display with 8 digits and Arduino

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/*
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 * Pin connections for a 7‑segment display driven by 74HC595
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 * Display[+5V]
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 * Display[SCLK] → PIN6
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 * Display[DIO]  → PIN5
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 * Display[RCLK] → PIN4
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 * Display[GND]
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 */
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const int Latch = 4;  // RCK
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const int Clock = 6;  // SCK
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const int Digits = 8; // Number of digits
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const int Start = 1 << (Digits - 1);
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/*
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 * Encode the segments for each numeral
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 */
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//   Digits          0     1     2     3     4     5     6     7     8     9
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byte symbolsEncoded[10] = {0xC0, 0xF9, 0xA4, 0xB0, 0x99,
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                            0x92, 0x82, 0xF8, 0x80, 0x90};
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/*
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 * Decimal point for a digit
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 */
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byte pointDigit = 0x80;
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// Screen buffer, left‑to‑right
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byte screenBuffer[8] = {1,2,3,4,5,6,7,9};
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void setup()
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{
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  // Set all used pins as outputs
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  pinMode(Latch, OUTPUT);
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  pinMode(Clock, OUTPUT);
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  pinMode(Data, OUTPUT);
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  Serial.begin(9600);
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}
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void loop()
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{
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  for (int i = 0; i < Digits; i++) {
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    // To start communication with the display we pull the latch pin low.
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    // While the latch is low we can shift out the value that encodes
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    // the required segments for the desired digit position.
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    digitalWrite(Latch, LOW);
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    // First we send the byte that encodes the numeral from our buffer
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    shiftOut(Data, Clock, MSBFIRST, symbolsEncoded[screenBuffer[i]]);
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    // Then we send the byte that encodes its position
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    shiftOut(Data, Clock, MSBFIRST, Start >> i);
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    // Finally we “latch” the data: set the latch pin high.
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    // If you don’t do this the display will show a garbled “mash”
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    // of lit segments.
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    digitalWrite(Latch, HIGH); // [!code focus]
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  }
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}