Bombs away!

If a customer sent us a disk with drilling hole data this made our job easy, but many times they only sent us artwork on film, or worse. In this case it was up to Daniel Donoso (a very nice guy from Chile) to digitize all the drilling locations for a board. You take a different color permanent magic marker for each hole size, and then you connect the dots making a track that leads through all the drilling positions.

Then you place the artwork on a large digitizing machine called an OPIC II made by Excellon. This had a large polished granite platform, and on top rested a platform on top of felt pads. The artwork is placed on the table, and then using two control wheels the table is moved with several decimal places of precision through the course laid out in marker. Daniel would sit and peer into a "bombsight" down at the table and drop imaginary bombs on each position with a foot pedal. Each time he did this the X and Y position of the table was recorded to paper tape. This could take a while to do, and it took practice.

One really cool thing about the OPIC II was the digital display for showing the X, Y coordinates. It didn't have an LED display. Instead each digit position had one of those little vacuum tubes that had incandescent filaments shaped like each digit. I guess this might have been a plasma display, and not incandescent, I'm not sure. If you looked carefully you saw that the different digits were not all the same exact distance from your eyes because they were all packed into the tube in a row, one behind the other.

The OPIC II could not be called a computer, but later on we would find a way to use a computer with this machine.