Babbage's Difference Engine and other historic computers

Seven vertical counting mechanisms

Difference Engine No. 2 had seven vertical counting mechanisms. Each with a column of 31 numbered gears.

Photo credit: Jitze Couperus


Bill Detwiler is Managing Editor of TechRepublic and Tech Pro Research and the host of Cracking Open, CNET and TechRepublic's popular online show. Prior to joining TechRepublic in 2000, Bill was an IT manager, database administrator, and desktop supp...