Digital-logic ag, Cmos map – Compaq MSB900 User Manual
Page 31
DIGITAL-LOGIC AG
MSB900/L Detailed Technical Manual V1.0
31
CMOS Map
continued...
Location
Description
0Eh
CMOS Location for Bad CMOS and Checksum Flags
Bit 7
= Flag for CMOS Lost Power
0
=
Power OK
1
=
Lost Power
Bit 6
= Flag for CMOS checksum bad
0
=
Checksum is valid
1
=
Checksum is bad
0Fh
Shutdown Code
10h
Diskette Drives
Bits 7-4 = Diskette Drive A
0000
= Not installed
0001
= Drive A = 360 kB
0010
= Drive A = 1.2MB
0011
= Drive A = 720 kB
0100
= Drive A = 1.44MB
0101
= Drive A = 2.88MB
Bits 3-0 = Diskette Drive B
0000
= Not installed
0001
= Drive B = 360 kB
0010
= Drive B = 1.2MB
0011
= Drive B = 720 kB
0100
= Drive B = 1.44MB
0101
= Drive B = 2.88MB
11h
Reserved
12h
Fixed (Hard) Drives
Bits 7-4 = Hard Drive 0, AT Type
0000
= Not installed
0001-1110 = Types 1-14
1111
= Extended drive types 16-44.
See location 19h.
Bits 3-0 = Hard Drive 1, AT Type
0000
= Not installed
0001-1110 = Types 1-14
1111
= Extended drive types 16-44.
See location 2Ah.
13h
Reserved
14h
Equipment
Bits 7-6 = Number of Diskette Drives
00
=
One diskette drive
01
=
Two diskette drives
10, 11 =
Reserved
Bits 5-4 = Primary Display Type
00
=
Adapter with option ROM
01
=
CGA in 40 column mode
10
=
CGA in 80 column mode
11
=
Monochrome
Bits 3-2 = Reserved
Bit 1
= Math Coprocessor Presence
0
=
Not installed
1
=
Installed
Bit 0
= Bootable Diskette Drive
0
=
Not installed
1
=
Installed
Continued...