INT 0C - IRQ4 - SERIAL COMMUNICATIONS (COM1)
Notes:  on many PC's, COM3 shares this interrupt
may be masked by setting bit 4 on I/O port 21h
this vector is modified but not restored by Direct Access v4.0, and
may be left dangling by other programs written with the same version
of compiled BASIC
SeeAlso: INT 54"DESQview",INT 5C"DoubleDOS",INT 7C"GO32"

See also: 0B

0C - IRQ4 - SERIAL COMMUNICATIONS (COM1)