Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Writer/Xls/Worksheet.php
private function writeZoom()
    {
        // If scale is 100 we don't need to write a record
        if ($this->phpSheet->getSheetView()->getZoomScale() == 100) {
            return;
        }

        $record = 0x00A0; // Record identifier
        $length = 0x0004; // Bytes to follow

        $header = pack('vv', $record, $length);
        $data = pack('vv', $this->phpSheet->getSheetView()->getZoomScale(), 100);
        $this->append($header . $data);
    }
private function writeZoom()
    {
        // If scale is 100 we don't need to write a record
        if ($this->phpSheet->getSheetView()->getZoomScale() == 100) {
            return;
        }

        $record = 0x00A0; // Record identifier
        $length = 0x0004; // Bytes to follow

        $header = pack('vv', $record, $length);
        $data = pack('vv', $this->phpSheet->getSheetView()->getZoomScale(), 100);
        $this->append($header . $data);
    }
Store the window zoom factor. This should be a reduced fraction but for
simplicity we will store all fractions with a numerator of 100.