It was AppleTalk that got the chop in OS 10.4.x. Tiger and Jaguar talk happily to Macs down to OS 7.6.1 over TCP/IP if the older Macs start the conversation, and OS X Macs can respond to overtures from 10.4.x over TCP/IP.

I've just verified this with:

Classic II, System 7.5

IIci, OS 7.6.1

PB 540c, OS 8.1

PB 1400c, OS 8.6

Beige G3 DT, OS 9.2.2

iMac 500, OS 10.2.8

iMac 500, OS 10.3.9

iMac 500, OS 10.4.10

which are all in my LAN. System 7.5 (the Classic II) cannot address any flavour of OS X, although it 'sees' the iMac with 10.3.9 but not the iMac with 10.2.8. This latter iMac 'sees' all of the others, but even though it offers to 'mount' (ie, share) a drive from the Classic II, doesn't do so. The lowest that it successfully addresseses is OS 7.6.1. OS 10.4.10 does not successfully address OS 9.2.2 or below, although I half-remember that 10.3.9 and earlier did address 9.2.2 some while back. Tiger actively rejects 8.1—9.2.2, but just fails to find 7.6.1 and below, although all of those Systems/OSs 'see' it, and 7.6.1 and up can share its volumes.

Is all that confusing enough?

de