Ultra ATA-133 is ide right?
Yes. ATA33, ATA66, ATA100, ATA133 are all IDE.
… and they are all compatible with each other.
[ot] I’m writing a massive ‘how to install a second hard drive’ tutorial right now’. Basically it will cover everything. It will be much like my Windows XP Security Guide - Straight up and to the point, with pictures as well! 
I should have it finished in a few days so keep an eye out for it [/ot]
[QUOTE=megamaced]
… and they are all compatible with each other.
u can use all of the lower speed ones like ata-33, ata-66, ata-100 with ata-133 but they’ll obviously work at the speed rated for e.g ata 66 when plugged into ata100 will wrk at 66mb/s