dale@lamont.ldgo.columbia.edu (dale chayes) (10/11/90)
An 8-bit decoder based on a '688 requires three "chips", the 688, a (half of a) package of pull-up resistors and the dip switch. If you don't need the user selectablility of the dip switches and have already made the leap to programable logic, you can do a single chip solution with almost any PAL. I prefer GALs (Generic Array Logic) myself mostly because of the easy re-programming (I never seem to have time to get it right the first time, but usualy have time to get it right eventually.) A nice feature of the GAL(PAL) solution, is that you have lots of flexibility about signal polarity and you can clock it if that is appropriate. Dale -- Dale Chayes Lamont-Doherty Geological Observatory of Columbia University Route 9W, Palisades, N.Y. 10964 dale@lamont.ldgo.columbia.edu voice: (914) 359-2900 extension 434 fax: (914) 359-6817