Port Allocations

HUNTER uses the NSC800 port map for all its I/O functions, including the keyboard, RS-232, etc. The following gives a list of the most useful ports which can be controlled from Basic using OUT or INP verbs or from machine code.

Address Decimal	Hex	Name	Description
1	1H	DSR	Bit seven is the DSR Input bit. 1 = Inactive, 2 = Active
2	2H	INPUTS	This port has a number of input functions: Bit 0 is Data In (Inverted from RS-232 line). Bit 1 = DCD. Bit 2 = Power low warning (1 = Power O.K., 0 = Power low). Bit 3 = TXCLK - also the Single Bit Input Port.
96	60H	ANGLE	Controls display viewing angle. Input value in the range 0-1FH
129	81H	V24OUT	Directly outputs to the V24 data line signal on bit 0. The output is voltage inverted i.e. 0 = +Ve, 1 = -VE
130	82H	RTS	RTS output bit
131	83H	POWHLD	Power control. bit 0 = 1 : HUNTER on, bit 0 = 0 : HUNTER off
132	84H	INVCON	V24 inverter control. bit 0 = 1 : Inverter on, bit 0 = 0: inverter off
133	85H	DTR	DTR output bit
135	87H	AUXPWR	Turns on the auxilary power to pin 10 on the D type connector. 1 = Power on, 0 = Power off
187	BBH	ICRPFG	NSC800 internal interrupt mask register. See NSC800 hand book.
224	EOH	PAGE	Memory paging register