IBM 5170 Technical Reference page 74

01 Primary display is attached to the
Color/Graphics Monitor Adapter in the
40-column mode.
10 Primary display is attached to the
Color / Graphics Monitor Adapter in the
80-column mode.
~
11 Primary display is attached to the
Monochrome Display and Printer Adapter.
Bit 3-Bit 2
Not used.
Bit 1
Math Coprocessor presence bit:
o
Math Coprocessor not installed.
1 Math Coprocessor installed.
Bit 0
The set condition of this bit indicates that
diskette drives are installed.
Note: The equipment byte defines basic equipment in the
,~
system for power-on diagnostics.
Low and High Base Memory Bytes (Hex 15 and 16)
Bit 7-Bit 0 Address hex 15-Low-byte base size
Bit 7-Bit 0 Address hex 16-High-byte base size
Valid Sizes:
0100H 256Kb system-board RAM
0200H 512Kb system-board RAM
0280H 640Kb 512Kb system board RAM
and the IBM Personal Computer AT
128KB Memory Expansion Option
1-52 System Board