It has been a few years but I have had quite a bit of experience with the original EIDE MAX and 486 boards. Sometimes they work great, sometimes they only partially work..like as a stand alone controller...and sometimes they don't work at all. It depends on your board BIOS. As I remember it you can jumper the MAX to either default settings = it updates your existing BIOS and controller to support LBA drives and acts as a secondary channel for drives 3 and 4 OR it can be jumpered to act a a separate stand alone controller = channel one drive 1 &2 and makes no attempt to effect your existing controller or BIOS. try it both ways. Sometimes it won't update but it will work as a stand alone. Is it possible to remove or disable your existing controller and use the Promise as a stand alone controller? Obviously you will have to not have a floppy drive but you might at least want to try this to see if the old controller card is your problem. With a CD ROM and network connection you may not need a floppy drive....depends on what you are planning on using this 486 for. Mark Rode The NOSPIN Group >I've run into a blank wall with my attempts to up grade an old 486 SX >system. I want to put a somewhat larger hard drive and CD-ROM into it, and >I thought that using a Promise EIDE MAX II upgrade and controller card would >do the trick. It seems like this should work, but it hasn't. The NOSPIN Group provides a monthly newsletter with great tips, information and ideas: NOSPIN-L, The NOSPIN Magazine Visit our web site to signup: http://freepctech.com