At least a solution

To fetch the current entry text, use the get method:

s = e.get()

You can also bind the entry widget to a StringVar instance, and set or get the entry text via that variable:

v = StringVar()
e = Entry(master, textvariable=v)
e.pack()

v.set("a default value")
s = v.get()

There, that is what I want, an external byte array. There is no such capability in a text nox, only an entry box. as near as I can tell.  The entry box should have scroll bar handlers, I will see.....

Yes, it does have scroll but they set up a bit differently! N ope, a sinle line of text only.  Keep looking.