I should have added to my original comment that I wasn't criticising the article, which I really enjoyed. Glad it was taken that way! It's really interesting t

I should have added to my original comment that I wasn't criticising the article, which I really enjoyed. Glad it was taken that way! It's really interesting that those early systems really did deal with deltas. Unbelievable that ideas from systems that have been and gone before people's lifetimes still prevail today. When was the last time users needed to know about deltas? Possibly skipping ahead impatiently here...