Help me ID this IC

[LaceSensor]

I have purchased a Lumiphone kit and want to know how it works

The IC has the markings
M74hCD4B1
6406008H

any clues?

[marmaliser]

I am guessing it is 74hCD4

[Thomas_H]

should be 74HC04 a six inverter circut.

wired as a generator with LDRs to change frequency.

Application note: http://www.changpuak.ch/electronics/RC_HCT_Generator.php

[LaceSensor]

Gotcha, thanks