I need to implement an 8-input OR function that is compatible to IC chips of the 7400 series.
I already found a few solutions, but none of them is perfect. A perfect solution would be an OR-gate chip of the 7400 series with 8 inputs and a reasonably low propagation delay (<30ns).
The only 74xx OR-gate with 8 inputs is the 744078 (OR/NOR multifunction). The only versions of it that I could find in stores was the CD4078BE by Texas Instruments, but unfortunately it is horribly slow (300ns @ 5V).
Another solution is to use a 8-input inverter with open collector like the SN74ALS762N and then simply connect the outputs to an inverter. The chip is also quite fast, but unfortunately not available in the store of my choice.
Yet another solution is to use two 4-input NOR-gates like the CD74HC4002E combined with a NAND-gate.
I could also invert the inputs and then use a 8-input NAND-gate.
Are there any better solutions that I'm not aware of? Are there other fast 8-input OR, NOR or buffer/inverter gates (with open collector) than the ones I mentioned?
UPDATE: I found another chip, SN74BCT756N, an open collector inverter with 2 x 4 inputs. For whatever reason, the 74756 and 74757 are not listed in Wikipedia's "List of 7400 series integrated circuits".