You should indeed be using DD disks if available, but unlike 5.25" DD vs. HD disks the difference in coercivity of 3.5" DD vs. HD disks is relatively small and in practice HD disks will usually work in a DD drive without any problems.
m ----- Original Message ----- From: Geoffrey Oltmans To: m...@bitchin100.com Sent: Tuesday, August 08, 2017 5:07 PM Subject: Re: [M100] 3.5" Media On Mon, Aug 7, 2017 at 4:33 PM, Kurt McCullum <kurt.mccul...@att.net> wrote: For those who have used a TPDD2 in the past, I have a question about media type. Do these drives prefer double density (720k) or high density (1.44mb) media? I've tested with both from by using recycled media from years gone by and both seem to work. My primary interest in the drive is to see if I can improve mComm but as I'm testing, I'd like to actually use the proper media. Kurt I wouldn't want to trust HD media on a DD drive and vice versa. HD media has pigment of a higher coercivity than DD media, and so HD drive heads have a higher write current strength in HD mode. You should be using DD disks in the TPDD2.