I read few months ago: driver update from the original USB-serial converter chip manufacturer kill the chinese clone chips.

In the Arduino documentation it is recommended to use only one of the +5v sources, the USB(PC programming side) or the host(the EP). But the adapter still works connected to the Enterprise so, I have left both the EP and the USB connected and then I've heard the familiar sound of Windows finding a new  device...

At the end the Chinese Arduino is not completely dead. I still can program it....

I was thinking of optocouplers, as them will give us total isolation of the Enterprise side, then it can see mere switches connected to its Joy1 port.

The program needs little modifications to light the leds, it can run almost the same.

I remember a Midi adapter with optocouplers I made for my Amiga 500+, and Midi operates at 31250 baud, fast enough for this project.

For the  STROBE signal(RTS) it can be connected directly as it can be referenced to +5v or 0v the same with the 10k and 82k resistors like in the Boxsoft's.

Then I need 6 optocouplers(4 ways and two buttons), but I need advice to select the best type for this task.

Zozo please, what optocoupler can I use to do it?

Ok, thanks. I will search the best option.

Another option, the PS2501.

Or the pc817.

Or TLP521.

Here you have the work in process of a mini-Boxsoft made with optocouplers.

This is the simplified schematic of my project.

Observe that in the case of the second fire button I am using "Keyboard K" on pin A2 of the Control 1 port instead of "Keyboard J" on pin A1.

Yes, it is.

It doesn't need logical gates and the uncommon EP side is perfectly isolated.

The operation as a joystick port is working.

I have limited time but I'll try putting a D-sub 9 pin connector to test the Neos mouse on it this night....