Before the advent of microprocessors on lab machines it was usual to manually digitise graphical output by fixing the chart paper
to a digitisation table and clicking a mouse at the required locations of the data curve. On the original D-Mac machine this produced paper tape output. I think this relpacement transferred
data directly to a nominated disk file.
Nick Williams at the controls. Keith Woods wrote a suite of user interface routines so the system could be used easily by UEA scientists from FORTRAN codes.
A typical example is shown here.