Two days after installing the replacement hard disk the computer is showing the same symptoms again-odd scraping and rebounding noises from the HDD, Windows XP blue screen errors ( some with stop code 0x00000024, some disappear too quickly to note ), and occasionally programs unable to find a particular file.
12.
It is critical that the encoder and decoder agree on which variety of LZW is being used : the size of the alphabet, the maximum table size ( and code width ), whether variable-width encoding is being used, the initial code size, whether to use the clear and stop codes ( and what values they have ).
13.
Further refinements include reserving a code to indicate that the code table should be cleared and restored to its initial state ( a " clear code ", typically the first value immediately after the values for the individual alphabet characters ), and a code to indicate the end of data ( a " stop code ", typically one greater than the clear code ).
