Are you talking about the actual controller, or about the IDE port? For the controller, you can have several devices (There probably is an upper limit, but I don't know it at the moment).
As for the actual port. You can have 2 devices per port. 1 master and 1 slave. That's all
Really? Your motherboard can support 18.3 EIDE devices?
I wish I could test this, but I'm afraid I don't have a mobo that has IDE channel strings for more than 8 devices (Giga-byte sells a mobo that has 4 IDE strings).
I also can't seem to find 0.3 of an IDE device. Maybe if I get a hacksaw?
I'll give you the benefit of the doubt, though and assume it's just yer fingers that are stupid and you typed 18.3 instead of 183. Still, most mobos can only support up to four (4) IDE devices. To hook up more than four (4) IDE HDD drives (for instance) you would have to add a second controller card (or you could throw some onto the SATA chains [if you have them] to get 2-4 more).
Since bla!! is saying the same thing I am, you need to tell him he's wrong as usual, too. Make sure you do a thorough job of being assinine, Lone, else people will think you're not paying attention.