Seagate STT8000A, Руководство по эксплуатации продукта

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ATAPI Interface Chapter 5
STT8000A Product Manual Page 49
Mode Parameter Header
The following table describes the Mode Parameter header.
Byte Description Value Meaning
0 Mode Data Length NN Select: Reserved
Sense: Length of Available Following Data
1 Medium Type NN Tape type
2 Device Specific Parameters WP,001,Speed Bit 7 = Write Protect, Bits 6-4 = 001, Bits 3-
0 = Speed Selection
3 Block Descriptor Length 00/08h If 8, Block Descriptor follows
The only supported Buffered Mode (bits 6-4 of byte 2) is 001, indicating that write
operations are buffered. Only the Speed Selection field can be changed.
The following table defines the tape speeds supported with QIC-3095 tapes.
Speed Tape Speed Transfer Rate
0000b Automatic Automatic
0001b 46 ips 489 Kbytes/sec
0010b 69 ips 733 Kbytes/sec
0011b 92 ips 1,000 Kbytes/sec
Mode Block Descriptor
The Block Descriptor is returned to the MODE SENSE command unless the DBD bit
in the command packet is set to one. If the Block Descriptor is not sent, the Block
Descriptor Length field (in the Mode Parameter Header) is 0.
Byte Description Value Meaning
4 Density Code NN Current Density
5-7 Number of Blocks 000000h Zero
8 Reserved 00h —
9-11 Block Length 000200h Always 512 byte blocks
The Number of Blocks is 0, indicating that all blocks in the media match this
descriptor, (the blocks are fixed 512 byte blocks).
None of the Block Descriptor parameters may be changed (Block Length is fixed).