Also this is a link for people 'LIKE ME' who want to understand why not to mix LS type logic chips with HC type CMOS chips.

In cases where you want to mix LS-TTL and high-speed-CMOS (which is often done...) use 74HCTMOS instead. Sometimes, even 74HCMOS can be used, but then they need pull-ups at inputs, if they are driven by LS-TTL output.

Kai