@FellippeHeitor Well I got back, read the posts, and dug up the old Win 7. I didn't save the code from before, so I typed it back in QuickBasic, and ran it in DOSBox. So this time, the program with DIM ran to completion. So whatever happened before to make it throw a subscript out of range error did not happen this time, and as we all know with computers, that means whatever I did last time was not the same. So my apologies. I don't know if this was some senior moment or eyesight situation, because my DOSBox renders a very small IDE. Now I wished I saved the damn snippet, so I could see what happened. My best guess is I may have typed a different variable like a1$(11) instead of a$(11). Anyway, a "blonder" moment indeed.
Conclusion. QB and QB64 act exactly the same way in the situations described.
Pete