The IDE port, CS4321, and 91C96 are all on the 5V buffered side of the bus. BD0-BD8 (buffered 5V data) go to all three devices, and BD8-BD15 go to both the IDE and ethernet controller. BA0 and BA1 (buffered 5V address lines) are in common with all three devices, and BA2 goes to both the ethernet and IDE port.

5V versions of the read and write strobes are common to all three devices. They all have independent select lines.

If the converter was holding any of the above lines in the wrong state, it could well adversely affect the ethernet controller. If the CS4321 is working correctly, but the ethernet isn't, the obvious problem area would be either the top 8 bits of the data bus or BA2.

pca