Oscilloscope clock (opens in new tab)

My lab partner and I did something like this in our Microprocessors course (Hi Dan!). We wanted to do it with a laser and galvanometers but ended only having time for hooking it up to an oscilloscope.

I still remember mapping out all 36 letters/numbers as XY coordinates.

You can actually output decent vector graphics signals from a sound card if you jump through some hoops to be able to output a reasonable DC signal.

I did something similar with some galvos, using an oscilloscope with a 'z' input (most Tek scopes have this) lets you modulate the beam intensity.

Somewhere I've got a copy of the Scelbi-Byte Primer which has an article from 1979 called "Beer Budget Graphics" where an R2R ladder is used to create a point display on an oscilloscope. Its tougher when you're using a 4Mhz processor :-)

EDIT: Update apparently its from the November '76 issue of BYTE.