No it not a misspelling of this;
The Computation Book.
For my Swords & Wizardry campaign up at Gold Star Anime I been having a lot of fun coming up with new adventure using these old maps. Although I am sure the three characters that got turned to stone last Wednesday wouldn't agree.
Computation Books are still being widely used and can found at various office supply stores on the internet or in your town. They are inexpensive, Amazon has one here for little under 12 dollars.
Even after 20 years of having this book, only half of the pages are full so you get a lot of use out of it.