Have a look at a recent A1200T conversion here:
http://www.swaug.org.uk/swaugforum/viewtopic.php?t=37You can see that yellow round IDE cables have been used. To be converted for use with the Amiga, a needle has to be heated up and used to carefully melt the hole that was filled in the cable's connector. The cable can then be used with the Powerflyer or 4 way IDE adapter.
