Its a XY oscope so the highest freq signal required in the schematic appears to be 1200 Hz look at his clock gen system around page 17. In the "good ole days"

Its a XY oscope so the highest freq signal required in the schematic appears to be 1200 Hz look at his clock gen system around page 17. In the "good ole days" you'd use IC opamps instead of transistor ckts to directly generate NTSC video signals at an analog level. There are a zillion google able links here is one: http://www.electronixandmore.com/projects/pong/index.html http://www.electronixandmore.com/projects/pong/index.html Or an example of digital logic driving a scope http://www.electronixandmore.com/projects/scopepong/index.html http://www.electronixandmore.com/projects/scopepong/index.ht... In the 80s or early 90s it was a "thing" in Z80 programming class to drive two DAC with a Z80 running some assembly language you wrote yourself to display a vector cube. Then you demonstrated your ability or lack thereof WRT trig and made the cube rotate. That took about two lab periods. There were a couple alternatives for that lab and I did a sampler where I had an A/D sample a bit less than 64K of sound at 8Ksamples/sec when a button is pressed and then it output the sample repeatedly. It was kinda fun.