Thanks for the links!
I already found the shareware, v2.6 version of 3_Drives, but it nags every time I start it. I also found a small util, named WBIDE, made by Winbond, that supposedly allows to use a second, Winbond ide controller without bios support, but haven't tried it yet. Some say, that Ontrack's Disk Manager also have a driver for secondary controllers.
4_Drives would be the greatest, since that supports fully the secondary controller, and that could be any make, and mfm, ide, scsi, esdi, it doesn't matter (as they say in the readme). Dustbowl Designs (makers of 3/4_Drives) seem to be long time inactive/dead, so it wouldn't be impossible that they set their utils freeware at the end. No infos about them anymore :/
Mike: Yea, todays computers support up to four ide drives natively. This util I search is for older computers, where in the bios setup I can only set two hard disks. These computers support secondary controller too (originally 4 mfm controllers could be set in the xt machines), but natively they can use only the first, all others (secondary, tertiary and quatemary) only with driver (in Dos' case). Thanks for the reply!