Interesting. I think the real question about "is it the same language?" is whether modern readers can still understand it.
For early modern English (think Shakespeare) then most modern speakers can. You'd probably have a basic understanding from reading, although missing some nuance. A lot of the jokes in Shakespeare come out better when they're performed, so you'd probably have a better understanding of it in the theatre.
For middle English (think Chaucer) then you'd struggle a bit. Vocabulary and grammar have changed a lot. Might have a few passages in the Canterbury Tales that make sense unaided, but in general, not really.
For early English (think Beowulf) ha ha, fat chance. Even scholars of early languages don't understand everything in it, there's a few words the meaning of which are lost, but in general about one word in fifty even looks familiar and it's probably a false friend.
So I'd probably put English at 'about 500 years old'.
How far back modern French speakers can understand French would be interesting. I can understand a fair amount of Latin from my knowledge of Spanish; and unlike eg. William the Bastard invading England and introducing a whole pile of new vocabulary, the French have the advantage of never having been invaded by the French ;-)

The industrial design has improved enormously since then, as well. The days of using the same connector for different voltages, or connectors which can be rotated are gone. Everything has a keyed connector or similar pokayoke that means it only fits to the correct place, and only one way around. CPUs don't suicide if you forget to attach their system cooler, they just throttle. Much better, and obvious in retrospect that it should always have been that way.
Apart from the front panel connectors on a motherboard, of course. Those fiddly little bastards can get straight to hell.