Seagate STT8000A - Manual (Page 44)

Chapter 5 ATAPI Interface
Page 36 STT8000A Product Manual
Issuing PIO and DMA transfer modes does not actually select these operations;
however, issuing these modes selects the rate of either type of transfer, as selected
by the DMA bit (bit 0) of the ATAPI Features register.
ATAPI Identify Device (A1h)
The protocol and timing of this command conforms to a standard ATA type
command as defined in ATA-2.
Note: This command is similar to the ATA Identify Device command except it uses
a different op-code. The ATA Identify Device command is aborted.
This command is generally intended to be used by a low-level ATAPI driver to
determine the number and type of ATA/ATAPI devices attached to the interface.
This driver might be able to program transfer rates and other parameters in the host
ATA (IDE) interface.
The following table defines the values returned by the drive.
Word Description Value Meaning
0 General Configuration 81C0h ATAPI Streaming Tape, Removable
Accelerated DRQ, 12 byte packets
1-3 Disk info: cylinders, heads 0000h Unsupported
4-6 Disk info: track, sector sizes 0000h Unsupported
7-9 Reserved 0000h —
10-19 Serial Number (20 ASCII characters) "N...N" Serial Number
20 Buffer Type 4002h Cap & Mech Sts bytes 6 and 7
21 Buffer Size 02D8h 14 frames of 52 data blocks=728
22 ECC Bytes Available 0000h Unsupported
23-26 Firmware Revision (8 ASCII
characters) "N.NN" Firmware Revision
27-46 Model Number (40 ASCII characters) Model Number. "Seagate STT8000A"
47,48 Disk info: mult-xfer, double word I/O 0000h Unsupported
49 Capabilities 0F00h IORDY supported. Logical Blocks
Addressing and DMA supported
50 Reserved 0000h —
51 PIO Data Transfer Cycle Timing 0200h Mode 2
52 DMA Data Transfer Cycle Timing 0200h Mode 2