SEM VCO buffer (was: RE: Japanese duals (was: Re: CA3046,SSM2 210&2220 Replacements)))

[Haible Juergen]

	>Another idea is to use a CMOS logic Schmitt trigger IC.  One of the
faster
	>logic familys. 

The ARP Odyssey uses a CMOS gate to detect the threshold (no schmitt
trigger, though).

How are CMOS schmitt trigger made (internally), btw ?
I know how to configure one from two inverters and two resistors, but I
have no idea how the genuine CMOS schmitt triggers are made.

JH.