SMPTE color bars: common NTSC test pattern
PM5544: common PAL test pattern
A test card, also known as a test pattern or start-up/closedown test, is a television test signal, typically broadcast at times when the transmitter is active but no program is being broadcast (often at sign-on and sign-off). - from Wikipedia
I've had so much happen in the last few months that everything outside of work has been put on hold temporarily. I miss writing and will be back as soon as things settle down a bit. There are past events I've yet to write about, as well as future art shows and gigs so hang in there!