Here is the archive of EWD memos. The last one is numbered 1318, that's one thousand three hundred and eighteen:
https://www.cs.utexas.edu/~EWD/
Many are hand-written in ink, in his distinctive handwriting. They have no cross-outs or corrections. Some are quite long, with pages of mathematical notation. They must have taken a lot of time to prepare. Here is a sample chosen at random, which turned out to be a very nice example: