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Model 618 & 620 Adapters
C.2.4 Write Configuration Word
This function allows writing individual words to the configuration space of a
specific device. The offset must be a multiple of two. The specific PCI device
is indicated together with the offset and byte data to be written.
ENTRY:
[AH]
[AL]
[BH]
[BL]
[DI]
[CX]
0xB1
0x0C
Bus Number (0. . . 255)
Device Number in upper five bits,
Function Number in lower three bits
Register Number (0, 2, 4, . . . 254)
Byte Value to Write
EXIT:
[AH]
[CF]
Return Code:
0x0 successful
0x87 - bad register number
Completion Status, set = error, cleared = success
The Bus Number, Device Number, and Function Number are found by
calling the Find PCI Device BIOS function with the Device and Vendor
ID of the Model 618 adapter.
204 PCI BIOS Functions