)
Values for COMM-DRV error code:
 00h	no error
 01h	buffer not set or attempted to change buffer for active port
 02h	port not active
 03h	transmit buffer full
 04h	receive buffer full
 05h	syntax error
 06h	invalid buffer size
 07h	invalid port
 08h	handler changed
 09h	invalid baud rate
 0Ah	invalid parity setting
 0Bh	invalid data length
 0Ch	invalid number of stop bits
 0Dh	invalid protocol number
 0Eh	IRQ changed
 0Fh	port changged
 10h	invalid threshold setting
 11h	invalid IRQ number
 12h	interrupts not enabled
 13h	invalid break syntax
 14h	fatal error
 15h	CTS error
 16h	invalid RS232 I/O port address
 17h	environment variable not set
 18h	error on IOCTL call
 19h	error during atexit cleanup
 1Ah	error mapping for direct calls
 1Bh	error opening device
 1Ch	unable to allocate memory
 1Dh	error on external micro card
 1Eh	card changed error
 1Fh	card type error
 20h	not supported
 21h	parent port error
 22h	card command buffer full
 23h	no subdevice for this port
 24h	unknown error
 25h	external card busy
 26h	no more timers available
 27h	INT 14 vector changed
 28h	INT 08 vector changed
 29h	DPMI error
 2Ah	TSR buffer too small (or nonexistent)
 2Bh	out of asynchronous resources
 2Ch	out of timer resources
 2Dh	out of "other" timer resources
 2Eh	file I/O error
 2Fh	hardware memory > 64K