Seagate STT8000A - Manual (Page 66)

Chapter 5 ATAPI Interface
Page 58 STT8000A Product Manual
Space command
Bit
Byte
7 6 5 4 3 2 1 0
0 Operation code (11h)
1 Reserved Space Code
2 (MSB)
3 Count
4 (LSB)
5 Reserved
The only Space codes that are supported are 001b (Filemarks) and 011b (End of
Data on Current Partition). For Space Filemarks, negative count (2s compliment)
indicates Space Filemarks Reverse.
The DSC bit is reset (0) after this command is accepted and is set (1) when the
command is completed and the drive is ready. REQUEST SENSE can then be used
to verify successful command completion.