IBM Personal System/2 60 Technical Reference page 43

Bit 4 When set to 1, this bit indicates the power-on check
determined that the memory size is not the same as in the
configuration record.
Bit 3 When set to 1, this bit indicates that the controller or drive
C failed initialization, which prevents the system from
attempting a power-on reset.
Bit 2 When set to 0, this bit indicates the time is valid. When
set to 1, this bit indicates the time is invalid.
Bit 1 This bit indicates if the installed adapters match the
configuration information. When this bit is set to 1, the
adapters do not match the configuration information.
Bit 0 When set to 1, this bit indicates a time-out occurred while
an adapter 10 was being read.
Shutdown Status Byte (Hex OOF): This byte is defined by the
power-on diagnostic programs.
Diskette Drive Type Byte (Hex 010): This byte indicates the type of
diskette drive installed.
BII Function
7 - 4 First Diskette Drive Type
3 - 0 Second Diskette Drive Type
Figure 3-15. Diskette Drive Type Byte
Model 60 System Board 3-17