Why Is It Called Chock-a-Block?

The name "chock-a-block" was derived from the machine's ability to read data from "blocks" - which were just that, physical blocks painted different colours.

What is the origin of the term chock a block?

Chockablock started out as a nautical term. A block is a metal or wooden case with one or more pulleys inside. Sometimes, two or more blocks are used (as part of a rope and pulley system called a "block and tackle") to provide a mechanical advantage - as, for example, when hoisting a sail on a traditional sailing ship.

Is chock full slang?

full to the limit; crammed. Also chock-ful, chuck-full, choke-full.