Function 21, subfunction 1 - set MPU MIDI base port.
Parameters:
eax = 21 - function number
ebx = 1 - subfunction number
ecx = number of base port
Returned value
eax = 0 - success
eax = -1 - erratic number of a port
Remarks:
Number of a port must satisfy to conditions 0x100≤ecx≤0xFFFF.
The installation of base is necessary for
function 20
.
To get base port use
subfunction 1 of function 26
.