Some quick clarifications :
1. I tried to mirror or cast my phone screen to another screen and the lag time was too great. The one screen was constantly behind the other and it made working annoying.
That's why I wanted to hardwire the 2 devices. To eliminate the lag.
And hard wiring the 2 devices would NOT be mirroring or casting, as those terms imply that the 2 devices are tied together wirelessly, I believe.
2. The dumb screens I have are older and have a VGA input. Using an HDMI cable makes NO sense as it would NOT connect the screens.
Because I didn't get a quick, definitive answer to my question, I went ahead and bought the inexpensive cables that tied my phone to the screens and tried the arrangement. Here are the results :
1. It worked immediately and without any additional hardware or software being needed and without a lag time.
2. Samsung phones starting at the Galaxy 8 and all higher models, have a built-in app/utility called Dex, which manages the linking of the phone to another screen/device.
Dex has quite a few settings and tweaks to make the second screen work well with the phone and I honestly haven't found the time yet to tweak all of the settings. I am going to guess that when I find the time, the arrangement will suit my needs very well.
3. Dex gets very good reviews online for its operation, so I haven't bothered to look for other apps that might be better. I also don't know if there are similar apps to tie an iPhone to a screen.
4. I have gone from a screen with an 8" diagonal size to one with a 19" diagonal or about 6 times the screen area.
I have 2 dumb screens sitting in different work areas and I can just walk up and plug my phone in and start work.
4. I wanted to use my phone and the apps on it because I find my phone and those apps much faster and more reliable, than either my laptop or my tablet.
I was an early adopter of Palm devices and have always had a Bluetooth keyboard and mouse to facilitate work on my phone. The screen is just small and the eye and back strain it causes, makes full-time work on it wearing.
5. Prior to coming up with the phone cable idea, I spoke to my IT person about all of this and he said :
- a tablet (Samsung or otherwise) would NEVER replicate the speed and reliability of a quality phone. Same thing for a laptop, same thing for iPad (which he owns)
- he recommended a Chromebook or Chromebook tablet so that I could use the phone apps on it. The primary issue with a Chromebook is that it doesn't have the phone capability that my phone does
- I didn't talk to him about tying my phone to the screens. It just occurred to me and it seems to be the best solution I have discovered
My primary computer needs are email and a to-do type app, to keep everything organized. The very best apps/programs for each (IMO) are Android phone apps, so I can use them on just my phone, my tablet or on a Chromebook if I bought one.
I believe that what I have set up is the best SW / HW solution for me.