Generation of 18k square wave

even easier:
use the PCA
of course, if you insist on using some antique or 'simple' chip, that does not apply

Erik

reference:
The PCA cookbook
www.intel.com/.../270609.htm

even easier:
use the PCA
of course, if you insist on using some antique or 'simple' chip, that does not apply

Erik

reference:
The PCA cookbook
www.intel.com/.../270609.htm