This is the first time that I have put my two cents in since joining the
Piclist two months ago, but I am familiar with the U.S. Digital LS 7083 and
LS7084 8 pin encoder interface chips.  The '83 has a ch A and B input and
ouputs upclk (bar) and dnclk (bar); there is a selector pin for X1 or X4
output.  The '84, which I have used, has ch A and ch B and a clock(bar)
output for X! and X4 mode; Also is a direction pin for up-dn. Availiable from
U.S. for $3.05 in singles from U.S. Digital 3800 N.E. 86th St.Suite A3,
Vancouver, Wa. 98661-1353. Sales phone 1-8---736-0194. I hope this helps.  I
have also used their 1000 ppr encoder (about $60.00)
Bill Merson
Mersonbill@aol.com