Tandon TM100-2A drives

A -2 should be a 40 track (48tpi) drive. The -4 would have been the 80 track (96tpi) drive - unless it's a -4M which iirc is 100tpi. If it hasn't fallen off, the Tandon drives have a little sticker up under the door opener handle - open the doot, then look up from the front bottom of the drive - inside the handle you may find a sticker reading "48 tpi" or "96 tpi". The term "quad density" was used by some people to describe a Double-Sided, Double-Densoty drive (4 times as much storage as a SSSD drive) - NorthStar used to describes their DSDD drives as "quad density" even though they were only 48tpi. Easy way to tell for sure - hook it up to your imagedisk machine, then gointo the "Align/test" function and step to track 40 - if the head travels the whole distance, the drive is 40 track - if it only goes 1/2 way, it's 80 track. Dave -- dave06a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Collector of vintage computing equipment: http://www.classiccmp.org/dunfield/index.html