The specifications in the PDF for the PDD1 and PDD2 says the following:
PDD1 (26-3808):
Disk
Number of surfaces 1
Number of Memory Blocks
Total number of tracks 40
Total number of hard sectors 80
PDD2 (26-3814):
Disk
Number of surfaces 1
Number of Memory Blocks
Total number of tracks 80
Total number of hard sectors 160
On 8/8/2017 12:39 AM, Gary Weber wrote:
> 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"!
After rereading this I wanted to make one critical point. Remember,
if yours is truly the TPDD2, it already is double sided. It formats
the drive as 100K per side (200K total). You use the "Bank" feature
in TS-DOS to switch between which side you're accessing. So, no need
to be fantasizing about flippy-floppies. ;-)
It was the original TPDD that is only 100K single sided.
Gary
On Mon, Aug 7, 2017 at 8:04 PM, Kurt McCullum <kurt.mccul...@att.net
<mailto:kurt.mccul...@att.net>> wrote:
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:m100-boun...@lists.bitchin100.com
<mailto:m100-boun...@lists.bitchin100.com>] *On Behalf Of *Brian White
*Sent:* Monday, August 07, 2017 4:41 PM
*To:* m...@bitchin100.com <mailto:m...@bitchin100.com>
*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
<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
<http://www.colorcomputerarchive.com/coco/Documents/Radio%20Shack%20Catalogs/Tandy%20Computer%20Catalog%20and%20Software%20Reference%20Guide%20%281988%29%28Tandy%29.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 <g...@web8201.com
<mailto:g...@web8201.com>> 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
<kurt.mccul...@att.net <mailto: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
>
--
Gary Weber
g...@web8201.com <mailto:g...@web8201.com>
