Hi Erv, my son works with me, and he is well into the electronic age. He uses his cell for everything that is out there, right in the customers home etc. Codes you name it, its all on line and I know as he is showing me how to just use the cell or tablet, to get the information I need. We also have all the manuals that AJ on this site has available, good reliable information.
My son uses just his cell, he pays 61.00 per month, unlimited everything, and that is all he uses to get the information he needs. I am slowly getting used to mine, and it has everything available if you know how and what your are after.
You say you have been into Commercial Refrigeration for many years. I also spent a good part of my life working on Ammonia and Freon plants etc. Am in my 28 years doing domestic refrigeration in the Major Appliance section. Only do drop offs at the shop now, my son does the inhome service. Am 68 and am not to active from the waiste down, old body is slowing down. Above the waiste, still 20 years old.
You will learn a pile on AJ's site here, lots of information, and a great bunch of techs here that are always willing to help. Good luck Erv.