The disk drives on the DEC2060 were the size of a small washing machine and held about 450 megabytes of data. If the file was correct, the plotter produced a page every 20 minutes or so. If there was an error the file had to be searched to discover the problem. We’re talking 1 colour monitors – no visuals on the screen – just code. It could have been a “91” typed instead of a “19” that caused the problem.