| 摘要 |
<p>Each broadcast page contains a row which is not displayed. In addition to the standard initial bytes CR (clock run in), FC (framing code) and MRAG (magazine number and row number of, there are 4 bytes allocated to a 16-bit cyclic run- dancy check code CRC for the page and 6 groups, of 6 bytes each, NEXT 0 to NEXT 5. Each 6-byte group is a pointer to another page address made up of page tens and page units, hour code tens and units and minute code tens and units. The three spare bits from the tens bytes for hours and minutes contain a number which is normally 0 but, if not 0, is added modulo-B in the decoder to the current magazine number in MRAG to derive the magazine number for the 'next' page. A specific line, not related to any particular page, can be transmitted say once a second and includes a 6-byte group addressing a title page.</p> |
