The 1130 had 120 power transistors, each wired to the print magnet for one printer column.

The magnet released a lever that engaged a cam with a spinning clutch shaft.

As the set of 120 print wheels spun, the 1130 received an interrupt as each of the possible 48 characters was about to move into position.

This put a big performance burden on the CPU, but resulted in an inexpensive (for the time) printer.

Sometimes a printer output line transistor would fail, resulting in a blank print position.