IBM ThinkPad 560Z, Дополнительное руководство

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Bits 3–2 These bits are reserved.
Bit 1 If set to 1, this bit indicates that a coprocessor is
installed.
Bit 0 If set to 1, this bit indicates that physical diskette drive 0
is installed.
Low and High Base Memory Bytes (X ' 015 ' and X ' 016 ' ): The
low and high base memory bytes define the amount of memory
below the 640-KB address space.
The value in these bytes represents the number of 1-KB blocks of
base memory. For example, X
'
0280
'
indicates 640 KB. The low
byte is X
'
015
'
; the high byte is X
'
016
'
.
Low and High Expansion Memory Bytes (X
'
017
'
and X
'
018
'
):
The low and high expansion memory bytes define the amount of
memory above the 1-MB address space.
The value in these bytes represents the number of 1-KB blocks of
expansion memory. For example, X
'
0800
'
indicates 2048 KB. The
low byte is X
'
017
'
; the high byte is X
'
018
'
.
Reserved Bytes (X
'
01D
'
–X
'
02D
'
): These bytes are reserved.
Configuration Checksum Bytes (X
'
02E
'
and X
'
02F
'
): The
configuration checksum bytes contain the checksum character for
bytes X
'
010
'
through X
'
02D
'
of the 64-byte CMOS RAM. The high
byte is X
'
02E
'
; the low byte is X
'
02F
'
.
Low and High Usable Memory Bytes (X
'
030
'
and X
'
031
'
): The
low and high usable memory bytes define the total amount of
contiguous memory from 1 MB to 20 MB.
The hexadecimal values in these bytes represent the number of
1-KB blocks of usable memory. For example, X
'
0800
'
is equal to
2048 KB. The low byte is X
'
30
'
; the high byte is X
'
31
'
.
Date-Century Byte (X
'
032
'
): Bits 7 through 0 of the date-century
byte contain the binary-coded decimal value for the century. For
information about reading and setting this byte, refer to the
IBM
Personal System/2 and Personal Computer BIOS Interface.
Reserved Bytes (X
'
033
'
–X
'
07F
'
): These bytes are reserved.
2-26 ThinkPad 560Z System Board