Mitsubishi Electric LS Pro Hardware Technical Reference page 49

System Board
The contents of each of the RTC RAM locations which requires further explanation
is described in the following table.
Location/Title
0E
Diagnostic
status
0F
Shutdown
code
10
Diskette
drive type
12
Fixed disk
drive type
13
Power on
password
14
Equipment
byte
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Bit(s) Function
7 1 = Real time clock lost power
6 1 = CMOS checksum bad
5 1 = Invalid configuration at POST
4 1 = Memory size error at POST
3 1 = Fixed disk fails initialization
2 1 = CMOS time found invalid
1, 0 Reserved
7-0 00h = Normal execution of POST
01h = Chipset initialization for real mode re-entry.
05h = Issue an EOI and JMP to 40:67h
06h = JMP to 40:67h without an EOI
07h = Return to INT 15h function AH=87h block move
08h = Return to POST memory test
09h = Return to INT 15h function AH=87h block move
0Ah = JMP to 40:67h without an EOI
7-4 Drive type of diskette drive 0
0000 = No drive
0001 = Not used (360k)
0010 = Not used (1.2MB)
0011 = Not used (720k)
0100 = 1.44MB
0101-1111 are Reserved
3-0 Reserved (no second drive)
7-4 Drive type for drive 0 (0-14) if 15 look at byte 19h
3-0 Reserved
7-1 Reserved
0 1 = Power on password enabled
7-6 Diskette drives installed
00h = 1
01-03h Reserved
5-4 Primary display adapter
00h = VGA
01h = Not used (40 column colour)
02h = Not used (80 column colour)
03h = Not used (Monochrome)
3-2 Reserved
1 1 = 80387 installed
0 1 = Diskette drive available for boot