Hard Disk Drive Type Byte (X
'
012
'
): This byte defines the type of
hard disk drive installed. X
'
00
'
indicates that no hard disk drive is
installed.
Figure
2-26. Hard Disk Drive Type Byte
Bit
Drive Type
7–4
Hard disk drive 0
3–0
Hard disk drive 1
Reserved Bytes (X
'
013
'
): These bytes are reserved.
Equipment Byte (X
'
014
'
): This byte defines the basic equipment
in the system for the power-on diagnostic tests.
Figure 2-27. Equipment Byte
Bit
Description
7, 6
Number of diskette drives
5, 4
Display operating mode
3, 2
Reserved
1
Coprocessor presence
0
Diskette drive 0 presence
Bits 7, 6
These bits indicate the number of installed diskette
drives.
Figure
2-28. Installed Diskette Drive Bits
Bits 7,6
Number of Diskette Drives
0 0
One drive
0 1
Reserved
1 0
Reserved
1 1
Reserved
Bits 5, 4
These bits indicate the operating mode of the display
attached to the video port.
Figure
2-29. Display Operating Mode Bits
Bits 5,4
Display Operating Mode
0 0
Reserved
0 1
40-column mode
1 0
80-column mode
1 1
Monochrome mode
ThinkPad 560Z System Board
2-25
