cd roms

can you have 3 cd rom drives and how would you connect when the tape only has connections for 2

 

i have a cd burner that burns fast but it doesnt play dvd, i have a dvd player but it doesnt burn and i just bought a dvd burner but i was told i had to keep the dvd player to use if i wanted to copy a dvd and it doesnt burn cds as fast

 

DVD burners are marginally slower in recording, but that's mainly because of that it's got that much more to burn. If you have a DVD-rw, there's no real reason to have another DVD rom unless you're doing drive to drive copies. But as you pointed out, having 2 devices on the same IDE cable is slow, as the cable can only read or write, not both at the same time.
The info coming from the DVD-rom is going to get stored in a temp file in the HDD before it get's written anyway, so you might as well just have the DVD-rw. This way you can rip the files to the HDD, then copy them to a blank, encode them in other formats, etc.