What happened to Apple older software?

I was just on Apples website and it appears most of the older software is gone. I needed to download the 7.5.5 update and it's gone.

I'm trying to connect a Mac Classic II to the internet. I have the Asante EN/SC adapter. Does anyone know if this will work with Open Transport? or.. Is there a better way to network using DHCP and a D-link router? I installed open transport but the only extentions I have are MacTCP and network. I've also installed the Asante drivers. What happened to TCP/IP? Yes I'm a newbe.

Dave...