While I was still running the station I had wanted to buy a computer to improve the business — not just for bookkeeping, but to track car maintenance services by time and mileage, send reminders to customers when an oil change or tuneup was due, and build the kind of systematic customer relationship that would grow the business over time. I did buy an address-making machine and tried to build a manual file system to do some of this, but it was slow and labor-intensive. Any computer, even the smallest PDP-11, was too expensive at the time.