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 Imput 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