COMPUTER MEMORIES, Chapter 28

MICROWAVE DATA TRANSMISSION
A project that I had nothing to do with, but watched with interest from across the room, was the installation of a Microwave Dish to transmit data from a computer at the Rocketdyne facility in the San Fernando Valley, to the headquarters of North American Aviation, near the LA airport, 25 miles to the south. There was a mountain in between that blocked line of sight, so a relay dish was installed on Oat Mountain, a higher mountain to the north, and the data was bounced from that dish, across the Santa Monica mountains, to the installation near LAX. I have not the slightest idea what the data rate was, or any other information about this system. I don’t have the exact date, but it was in the late 1950s.

A CONFLICT WITH THE ALL STAR GAME
Back in the mid-50’s modified keypunches could read an 80 column IBM card, then send that information over telephone lines to another modified keypunch. It seems the data rate was 240 bits per second, but maybe it was still 120, or perhaps it had increased to 480 by now. Don’t remember that detail exactly.

One day I was trying to send some very important rocket engine data from Rocketdyne in Canoga Park, CA, to a plant in Neosho, Missouri. Data would be sent for a few minutes, then we would be off the air. I would make a call to the telephone company and complain, then a few minutes later, we would be back on the air again, then in a few minutes, off.

Finally I got hold of the telephone company in Missouri and discovered that we were trying to use the same telephone line that the radio network was using to broadcast the Baseball All Star Game. When they were on the air, we were off. After some complaint, we would get the telephone line until they complained and took over. What a mess, but there just weren’t all that many telephone lines that were good enough to transmit data, even as crude as our equipment was in those days.