Oops, thanks Steve and Dave.

It looks to me that 4, 8, 12, and 16 mhz crystals can be used, but they show no examples of higher crystal operation. Unless I am wrong again, it looks to me like 16 mhz is max for this. I have a 47j53 running on a 12 mhz crystal, and I have never seen an example of them running higher than 16.