Kenhughes,
Thanks for the "nybble" info. I'm sure you are right that it was originally written with a "y"; however, common usage over the last 20 years has moved, it appears, more to "nibble".
c.f.
wikipedia
Indeed, there are even those who argue that a Nybble is to a nibble as a byte is to a bit. But I think they are biting off more than they can chew!
And yes, I am a saad old dastard!
SD