HP 5961-0509 manual Command Byte

Table 15-7

Command Byte

7 5 4 0

Number of bytes to replace (1-8)

Relative offset from last untreated byte

If more than eight replacement (delta) bytes are needed, additional command byte/replacement bytes may be added, as shown below:

EC*3m#W [(Command Byte)(1 to 8 Replacement Bytes)][(Command Byte)(1 to 8 Replacement Bytes)]. . .

In the command byte, the upper three bits identify the number of replacement (delta) bytes (which can be 1 to 8 bytes). The lower five bits identify the location the replacement bytes are to be positioned. This position is identified as some number of bytes in, from the first untreated byte, referred to as the offset. For example, if there are 5 replacement bytes and the offset is 7, then the replacement bytes replace byte 7, 8, 9, 10, and 11 (the five bytes beginning at byte 7 from the seed row).

If there is more than one replacement in a row, the second offset is counted from the next untreated byte in the row: the first byte following the last replacement byte.

Figure 15-9

EN Set Compression Method Command 15-21