Model 100 Serial Interface

Configuration

Serial Word Format

Port $D8 controls the serial word format.

Bit	Function	Note
0	Stop bits	0 => 1 stop bit; 1 => 2 stop bits
1	Parity	0 => Odd parity; 1 => Even
2	Parity Inhibit	0 => Parity; 1 => No parity
4-3	Character length selected	Number of bits: 00 => 5, 01 => 6, 10 => 7, 11 => 8
7-5	Unused

I/O Map

Name	Direction	Port
TX	Output	$C8
RX	Input	$C8
RTS	Output	$BA, bit 7
CTS	Input	$BB, bit 4
DSR	Input	$BB, bit 5
DTR	Output	$BA, bit 6

Direction indicates both data flow, and whether to use an IN or OUT instruction to read/write to the given pin.