Sometimes I feel frustrated when my messages are being ignored.
What you have asked have been answered.
I tried to study how to do in VB6.0 for having the idea.
For VB6 solution, as I have written, since it is a desktop windows application, it is easy to do.
You just need to set the Form startup position to x, y point which is on another monitor when the Display settings is set to
Extend.
Let say the first monitor have resolution of 1024 pixels wide, then if you set the second form to display with position let say x = 1028 (adding some buffer gap, this is trial and error) then the second form will be appear in the second monitor. You need to adjust the form size accordingly to fit the screen.
My experience with my previous job is that the software was design in such a way and all the shops are using the same hardware, so there will be no compatibility issue. All terminal will be install (clone) from a workable windows image (Ghost).
But why you want to use VB6?
It won't work for Android! You can only try on a PC with 2 VGA or display ports.
I'm interested in B4A how to do. I don't know how to extend monitor in android device.
In Android OS and hardware, it is a different case.
I have already proposed several solutions.
eg. Bluetooth, WiFi, MQTT or use timer to pull data from a first tablet database
For me, MQTT is a good solution for 2 Android devices.
I don't know why you ask this question at the first place.
If you are just curious, you get short answers.
If you are serious to get a solution for business purpose, then there are much for discussion.
However, I don't see you are keen and easily give up.
Language barrier for me is not an issue at all as we can use translator.
I understand people with low self-esteem or imposter syndrome because I am/were one. I also a shy person and have lack of confidence most of the time.
But if you believe you want to create something, just don't easily give up.
People replied to you because they want to help you.