Thanks Brian & Garry,
I suspected that to be the case but when my HD disk appeared to work I thought I would ask. Kurt From: M100 [mailto:[email protected]] On Behalf Of Brian White Sent: Monday, August 07, 2017 4:41 PM To: [email protected] Subject: Re: [M100] 3.5" Media I wasn't using these when they were current, but... No question double density. Aside from the dates when these things were sold, or the fact that the actual formatting is far less than double density, or the fact that the original utility disk that came with it is double density, which are each solid points on their own... The manual for PDD-2 says to use cat 26-415 or 26-416, and those catalog numbers are not only double density but actually single sided. Double-sided doesn't hurt anything of course, although it's too bad you can't make 3.5" flippy disks as easily as you could 5.25"! But trying to use SD/DD read/write head signal strength on HD media is going to either not work at all, or work very poorly/unreliably, or worse, *appear to work but be corrupt*. Because the HD media is more sensitive than the older media, and operates at lower signal strengths than the older media. An SD or DD drive write signal is stronger to match the weaker media it was meant for. So in effect you are over-driving the newer media. In plain audio you can tell when that's happening because you actually hear the distortion like a ripped speaker. As data, you can't hear it directly or tell it's happening, which makes it more dangerous. They should have made HD disks so they don't even fit in older drives. Make them slightly longer maybe, so that old disks could still fit in new drive, but new disks couldn't fit in old drives. The guy who sent me my copy of the utility disk sent one of each type, and the HD copy actually works, which is what I mean by "dangerous", because, going by that, you would conclude "It works, so, it works." Jump to page 6 http://www.classiccmp.org/cini/pdf/Tandy/Portable%20Disk%20Drive%202%20Operation%20Manual.pdf Jump to page 41 http://www.colorcomputerarchive.com/coco/Documents/Radio%20Shack%20Catalogs/Tandy%20Computer%20Catalog%20and%20Software%20Reference%20Guide%20(1988)(Tandy).pdf That catalog doesn't say DD explicitly, but it does say others are HD and 1.44M explicitly, which makes everything else not-HD by omission. I assume that somewhere a more authoritative reference on the catalog numbers would show that more explicitly. -- bkw On Mon, Aug 7, 2017 at 6:41 PM, Gary Weber <[email protected] <mailto:[email protected]> > wrote: Double Density for sure. A long time ago, I had attempted to format a high density disk on a TPDD2 but it gave an error. I've always had to use double density disks. On Mon, Aug 7, 2017 at 2:33 PM, Kurt McCullum <[email protected] <mailto:[email protected]> > 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 > -- Gary Weber [email protected] <mailto:[email protected]>
