INT 15 - Intel System Management Bus - RETRIEVE CRITICAL MESSAGES
AX = 53B0h
BH = 07h
CX = 6941h ('iA')
Return: CF clear if successful
AH = 00h (SMBus OK)
AL = device address
BX = device message
CF set if error
AH = error code (05h,07h,08h,09h,0Ah,86h) (see #00484)
Desc: retrieves oldest queued critical message from an SMBus device to the
host
Notes: up to five messages are queued; if the queue is full, messages will be
lost and error 09h returned