I just got a Digiac model 5504 disk drive exerciser through eBay. It didn't include any documentation. The basic features seem pretty straightforward, but I'm hoping to find documentation to figure out the less-obvious stuff, like those "fault enable" switches under a locking cover. It'll probably make an appearance on my web page eventually. For now, curious folks can see pictures of it on the eBay listing: http://www.ebay.com/itm/230590661812 I plugged it into a 5.25" floppy drive and was able to start and stop the motor and move the heads around. I'll probably try to get some alignment floppies one of these days. -- Mark J. Blair, NF6X <nf6x at nf6x.net> http://www.nf6x.net/