Atapi Interface - Seagate STT20000A Product Manual

Chapter 5

ATAPI interface

Page 38
The following table lists the ATAPI interface commands for the drive. In this table,
DSC restrictive means that the host should wait for DSC to be set before issuing the
command for minimum IDE bus overhead. Note that all ATAPI commands are 12
bytes in length. The command descriptions show only the first 6 or 10 bytes of these
commands, even though the commands are actually 12 bytes long.
Code DSC Command
Restrictive
00h
Y TEST UNIT
READY
01h Y REWIND
03h N REQUEST
SENSE
08h buffer READ
0Ah buffer WRITE
10h
Y WRITE
FILEMARK
11h
Y SPACE
12h N INQUIRY
15h — MODE
SELECT
19h Y ERASE
1Ah — MODE
SENSE
1Bh Y LOAD/UNL
OAD
2Bh Y LOCATE
34h Y READ
POSITION
3Bh — WRITE
BUFFER
Comments
Not DSC restrictive on some other drives.
Null status if DSC not set.
Delay occurs if first READ is not READ 0 blocks.
Write 0 not required to initialize DSC.
Flush always. WFM 0 to flush.
Space forward/reverse Filemarks and space to
EOD only.
DSC not affected.
Select speed, FDP, page 2B updates only.
Constitutes a logical erase; accepted at BOP0/1
or EOD only.
UNLOAD to make not ready; LOAD to return to
Ready. LOAD w/Retension any time. (All LOADS
imply REWIND and select partition 0.)
Locates logically only; can also select partition.
Also used to wait for previous command done.
Use for download only. Drive must be "unloaded".
STT20000A Product Manual
ATAPI Interface