SCSI Operation Code Table Format Explanation

The following shows several a small section of operation code table entries with each column of the table identified in detail.

|-> Operation Code value (in hexadecimal)
||
||  |-> Codes identifying how devices the operation code
||  |-> value.  (See detailed description below.)
||  |
||  |            |  |-> SCSI Command represented by the operation code
||  |------------|  |-------------------------------------------------|
    DTLPWROMAEBKVF
00  MMMMMMMMMMMMMM  TEST UNIT READY
02  VVVVVV V
04  M    O O        FORMAT UNIT
04   O              FORMAT MEDIUM

The DTLPWROMAEBKVF letters head one column each for the several standardized SCSI device types. In the hyper-text tables, you will note that the DTLPWRSOMCAEBK column heading letters are repeated frequently. This should help you correlate column entries with the SCSI device types that the represent.

The DTLPWROMAEBKVF letters stand for specific SCSI device types as follows:

In each DTLPWROMAEBKVF column, a letter (or blank) indicates the usage of the listed operation code by each specific SCSI device type. A blank in a column indicates that the listed operation code does not represent the listed command for the specific SCSI device type.

One operation code can represent different SCSI commands for different SCSI device types. The example shows this for the FORMAT UNIT and FORMAT MEDIUM commands. The FORMAT UNIT command uses operation code 04h for disk devices, while the FORMAT MEDIUM command uses operation code 04h for tape devices.

The letters in the DTLPWROMAEBKVF columns describe the requirements placed on the specific SCSI device type for the listed operation code and SCSI command. The following letters are used and have the noted meanings: