Abstract: An improvement to a chart recorder where the chart paper is driven by a motor responsive to pulses counted by a microprocessor makes it possible for the operator to return the pen at any time to the starting point of the last chart scan by merely pressing a key. Using a programmed counter the microprocessor keeps track constantly of the number of counts since the start of the scan. On key command the microprocessor directs the motor to return through this number of counts plus 50; then to go forward 50 counts thus taking up any backlash in the chart drive so as to return exactly to the initial point of the scan. The subroutine also raises the pen during return and lowers it at the starting point.