Many thanks for everyone who has helped me with this subject....

After having a good look at the HCTL2016 chip... I think I can do the whole
job with it alone (ok one for each stream...)

I have a 24bit wide I/O card for my PC with which I can drive the 2016s... A
two chip solution!!!!!!

The only problem I can see is the distance from the encoders to the PC...
about 30 feet!!! If I put the 2016s right by the encoders then I hav a long
parallel cable... Not good! But if I put the 2016s next to the PC then I
have long leads carrying the quadrature signals... Very noisy.... Any
ideas???


Phil