Band (MHz)	A	B	C	D	position
50	0	0	0	0	0
144	1	0	0	0	1
222	0	1	0	0	2
432	1	1	0	0	3
903	0	0	1	0	4
1296	1	0	1	0	5
2304	0	1	1	0	6
3456	1	1	1	0	7
5760	0	0	0	1	8
10GHz	1	0	0	1	9
24GHz	0	1	0	1	10
47GHz	1	1	0	1	11
76GHz	0	0	1	1	12

BCD bits go high for the band activated.
Data bit A is the `Least Significant Bit` (LSB) and data bit D is the `Most Significant Bit` (MSB).
N3FTI`s decoder uses bit D for a second function - to select 5760 and up `Microwave setup` stuff.
The logger`s band encoder can be set so 50MHz starts at position 1, non-logical 0.

Decoder inputs are connected to LPT1 as follows:

A	LPT Pin 2
B	LPT Pin 7
C	LPT Pin 8
D	LPT Pin 9
Grnd	LPT Pin 15

When CW is selected on LPT, connections are as follows:

Emitter Q1	LPT Pin 1
Base Q1, with 3K-ohm series resistor	LPT Pin 17
Collector Q1	Rig key jack
Rig CW ground	LPT Pin 18
Q1	2N4401

If a TopTen decoder is used, this setup supports CW to the rear panel RCA jack.

I will try to code PTT to LPT ??

Emitter Q1	Rig Ground
Base Q1, with 3K-ohm series resistor	LPT Pin 16
Collector Q1	Rig PTT jack
Q1	2N4401