Believe or not, when I was way too much the geek, I built an echoer with 8K Static RAM and no processor at all. The timing was all controlled by a PLL (phase lock loop) oscillator and it worked great. Had fun with it in my Engineering College dorm. I actually updated it to 32K static (pretty much pin for pin compatible with the previous chip; some of the unused pins now had a purpose. lol) when the cost went down for the new chip (believe it was $20 for that chip as I recall; a lot for a broke college kid. lol). Those were the fun days. Wrote programs for my HP 28S too. Now, being old, I'm also lazy. Now everything has to be written as a program which requires a processor of course. But I digress. It was cool that at least, as a prood of concept, a simple timer like animation can be done without any real programming. A true clock, of course, can't since there really isn't any way to set the time.