IBM 5170 Technical Reference page 71

Bit 6
Configuration Record-Checksum Status
Indicator-A 0 indicates that checksum is good,
and a 1 indicates it is bad.
Bit 5 Incorrect Configuration Information-This is a
check, at power on time, of the equipment byte
~
of the configuration record. A 0 indicates that
the configuration information is valid, and a 1
indicates it is invalid. Power-on checks require:
• At least one diskette drive to be installed (bit
o
of the equipment byte set to
O.
•
The primary display adapter setting in
configuration matches the system board's
display switch setting and the actual display
hardware in the system.
Bit 4 Memory Size Miscompare-A 0 indicates that
the power-on check determined the same memory
size as in the configuration record and a 1
indicates the memory size is different.
~\
Bit 3
Fixed Disk Adapter/Drive C Initialization
Status-A 0 indicates that the adapter and drive
are functioning properly and the system can
attempt "boot up." A 1 indicates that the
adapter and/or drive C failed initialization, which
prevents the system from attempting to "boot
up."
Bit 2 Time Status Indicator-(POST validity check) A
o
indicates that the time is valid and a 1 indicates
that the time is invalid.
Bit 1-Bit 0
Reserved
Shutdown Status Byte (Hex OF)
The bits in this byte are defined by the power on diagnostics. For
more information about this byte, see "BIOS Listing."
System Board 1-49