Instruct: Classify the given review into positive or negative sentiment.
Query: Very handy!

I'm a device driver programmer, and I've owned the 3rd edition (1990) of this for years. I seriously use it at least once per week. Sometimes, it's just for the ASCII table (which one can find lots of places), but I also use many other things, such as the ISA pinout, 16550 register map, I/O map, etc. It's a very simple book, but it's small and very handy.