That's hard - I do have scans of most of Byte, but I don't have many of PCW, so it's hard to remember. I still have a lot of printed PCW magazines stored somewhere, but I can't exactly go and look through them where they are.
But I think Byte was all good until at least 1986-1987, and PCW almost as long but I'm uncertain about the latter.
I subscribed to PCW from issue no. 2 (after finding issue no. 1 in a local shop, and the shop had a system where you could get them to set up the subscription for you - so I did that on the spot. Those were the days..)
And I stopped subscribing at some point, after the aforementioned "review commercial business software" change of focus. But I can't remember when that happened. I may also have dumped the later issues already (because of that), so even if I go look up the stored mags I may not be able to tell. Unlike Byte it's hard to find scanned complete PCW issues.