C64 RS232 User port

Note: Availble on the Commodore C64/C128. Software emulated. The signals do not have true RS232 levels. It's TTL level, and RXD/TXD is inverted. It's just the normal User Port, used as a RS232 port.

Pin Function RS232 Details

A	GND	GND	Protective Ground
B+C	FLAG2+PB0	RxD	Receive Data
D	PB1	RTS	Ready To Send
E	PB2	DTR	Data Terminal Ready
F	PB3	RI	Ring Indicator
H	PB4	DCD	Data Carrier Detect
K	PB6	CTS	Clear To Send
L	PB7	DSR	Data Set Ready
M	PA2	TxD	Transmit Data
N	GND	GND	Signal Ground

**Must be applied to both pins

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