Specifications

64 AMD Geode™ GeodeROM Functional Specification
Non-Removable Media
32087C
42h
1
7 BYTEs PC/XT only disk subsystem command/status bytes.
49h BYTE Current video mode.
4Ah WORD Number of columns in current text page.
4Ch WORD Size of current video page in bytes.
4Eh WORD Current video page start address.
50h 16 BYTEs Row/column of cursor position in each of eight text video pages.
60h WORD Video cursor type, 6845 compatible:
MSB = Startline
LSB = Endline
62h BYTE Video current page number.
63h WORD Video CRT controller base address:
Color = 03D4h
Mono = 03B4h
65h BYTE Video current setting of mode select register 03D8h/03B8h.
66h BYTE Video current setting of CGA palette register 03D9h.
67h DWORD Real mode re-entry address for BIOS shutdown from protected mode sequences.
6Bh BYTE Ordinal value of last spurious interrupt.
6Ch DWORD Number of IRQ0 timer ticks since 12:00AM.
70h BYTE Date rollover flag: Non-zero if timer has overflowed (crossed midnight) since the last INT 1Ah
GET_TIME call.
71h BYTE Ctrl-Break status: Bit 7 = 1 if Ctrl-Break key has been pressed.
72h WORD System reset signature: Contains 1234h during CTRL-ALT-DEL (warm) boot.
74h
1
BYTE Status of last fixed disk operation:
00h = No error
01h = Invalid function requested
02h = Sector address mark not found
03h = Disk is write protected
04h = Sector not found
05h = Reset operation failed
07h = Drive parameters invalid
08h = DMA overrun
09h = Attempt to DMA across 64K page boundary
0Ah = Bad sector error
0Bh = Bad cylinder
0Dh = Invalid number of sectors requested
0Eh = Control data address mark found
0Fh = DMA arbitration error
10h = Unrecoverable CRC error
11h = ECC data correction occurred
20h = General controller failure
40h = Seek operation failed
80h = Drive timed out
AAh = Drive not ready error
BBh = Unknown error
CCh = Error during write
E0h = Unknown error
FFh = Media sense failed
75h
1
BYTE Number of installed fixed disks.
Table 6-3. Format of the BIOS Data Area (Continued)
Offset Size Description