Remember test patterns in the middle of the night?

My earliest memories are from the black and white television era of the late 1950s. Our first television was housed in a large wooden console that took up a sizeable portion of the living room.  In those days, if you wanted to change to any of the five channels that were available at the time, you had to actually get out of your chair and manually turn the channel selector knob - every time.  Now you only need do that when you run down the batteries in your remote.  Our television was high tech.  The channel changer was a rotary dial and when you pressed the button of the desired channel it started to automatically change to each channel until it reached the number you had depressed.  Oooo - aaahhhh.  We kids almost wore it out, pressing the buttons and enjoying the wonders of automation.

There wasn't as much programmed viewing in those days and each evening the stations eventually signed off with the recital of the Television Code, the playing of the national anthem, and the screen went to a test pattern with an annoying test tone. I have read up a little on this (I love Google!), and learned that the purpose of the test pattern design was to help you adjust your vertical and horizontal linearity.  Duh!  Who knew?  We always did that in the middle of the program!