The second edition of Niasn ans Schockens's book, The Elements of Computing Systems in the Kindle version became available for purchase and download today. The hard copy edition will apparently begin shipping tomorrow.
Good to see the book update. Looked over the 2nd edition updates. I couldn't tell how much was changed besides the appendices. One thing I'd like to have seen would be advanced extensions or alternative implementation recommendations. The posthumous acknowledgement to Mark Armbrust is quite thoughtful and well deserved.
I am very fond of the 1st edition and having gone through nearly a half of it I don't know how it could be improved. However I will purchase this 2nd edition one day when my 1st edition gets worn out. But I will still keep my 1st edition as I value it greatly.