Function Name: UNTLK

Purpose: Serial - send untalk
Call address: $FFAB (hex) 65451 (decimal)
Preparation:

	Registers:	none
	Memory:		system map
	Flags:		none
	Calls:		none

	Registers:	.A used
	Memory:		STATUS ($90)
	Flags:		none

Description: UNTLK is a low-level Kernal serial bus routine that sends and UNTALK command to all serial bus devices. It commands all TALKing devices to sop sending data. (Most applications should us the higher-level I/O routines; see CLRCHN).

EXAMPLE:

	JSR	$FFAB	;UNTALK serial device