> 
> >Regarding my previous problem (see "PIC18F452 and NPN transistor to 
> >control PWM flow"), I've decided to go with two AND gates to 
> let pass 
> >only one signal out of two, and then I'll use an OR gate to 
> merge the 
> >two outputs into one wire.
> >
> >My question: are there any chips that encapsulate at least 2 
> AND gates 
> >and 1 OR gate in only one package? The perfect chip would be 
> one with 2 
> >ANDs, 1 OR and 1 NOT, but since I already have two traces to control 
> >the two AND gates, the NOT is dispensable. Cheers
> >Padu
> 
> Strangely enough, there was such a chip, at least in my TTL 
> days.  It was called an "AND-OR-INVERT" with its own part 
> number.  I figured somewhere there must have been an obvious 
> need for such a thing. Probably wouldn't cost much more than 
> a PIC, either :-)
> 
> Barry
> 

A quick glance at The TTL Data Book Vol. 2, 1985...

Available as TTL, L, LS, some as S, some as H and probably a few made it
forward to CMOS process but I haven't checked.

7451 Y = !(AB + CD), dual
7452 Y = AB + CDE + FG + HI + X in the J and N package or
     Y = AB + CD + EF + GHI + X in the W package (center VCC/GND)
7453 same ( I think) as 7452 but with inverted output
7454 Y = !(AB + CD + EF + GH)
7455 Y = !(ABCD + EFGH) and as the 74H55, it also had X and !X enable
gates
7464 Y = !(ABCD + EF + GHI + JK)
7465 same as 7464 but with OC output

Lots of other variations, two much work to type it all in.  Nice to have
around old TTL data books sometimes.

But, none of these are independent gates.  They are all set up to
implement sum-of-of-products equations.

Rob
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