HP C737990900 Technical Reference Manual page 112

00011b The drive returns a 4-byte descriptor for the buffer identified by the Buffer ID field. Invalid
01010b The drive returns data from the Echo Buffer. The Buffer ID and Offset are ignored.
01011b The drive returns the Echo Buffer descriptor. The Buffer ID and Offset are ignored.
The Buffer ID indicates which buffer is to be read. The buffers are defined as follows:
Buffer ID
Buffer ID
00h
01h
02h
10h
11h
12h
13h
20h
21h
22h
23h
Buffer Offset The Buffer Offset field may be set to any address in the buffer, but must obey the specified Offset
Boundary.
The amount of data to return. Allocation Length + Buffer Offset must be within the buffer size.
Allocation
Length
Main Buffer Memory
112 Commands
buffer IDs will return a buffer descriptor of all zeros.
The Buffer Offset field must be zero.
Memory Area
Main buffer memory
Processor addressable memory
SCSI burst buffer
or FC burst buffer
CM EEPROM
Mechanical EEPROM
Head assembly EEPROM
PCA EEPROM
Main buffer segment 0
Main buffer segment 1
Main buffer segment 2
Main buffer segment 3
Memory Sizes:
Size: 64 MB, reported size FFFFFFh. Because the buffer is greater than 16 MB,
additional buffer IDs have been defined to allow the buffer to be accesssed in 16 MB
segments. these are as follows:
Buffer ID
20h
00000000h + Buffer Offset (same as Buffer ID 00h)
21h 01000000h + Buffer Offset (in other words, +16 MB)
22h 02000000h + Buffer Offset (in other words, +32 MB)
Category Offset Boundary
1 byte
RAM
1 byte
RAM
4 bytes
RAM
512 bytes
1 byte
EEPROM
1 byte
EEPROM
1 byte
EEPROM
1 byte
EEPROM
1 byte
RAM
1 byte
RAM
1 byte
RAM
1 byte
RAM
Address
see below for details
see below for details
see below for details
see below for details