On my Amiga, which uses double sided double density media, formatted 880k, I 
never was able to use HD floppies. They'd always have formatting issues or 
would get disk errors more easily.

Luckily I have a bunch of old hard drive backups from the 90s that are 
useless... which means I have a bunch of written-once, probably good media 
around!

I've got a couple TPDD drives (not sure if tpdd1 or 2) with my Model Ts but 
I've never used it to be honest. It seems to spin up but I'm unaware if the 
belt is failing, etc. 

Sent from your iPhone.

> On Aug 8, 2017, at 8:42 AM, Kurt McCullum <kurt.mccul...@att.net> wrote:
> 
> Interesting. The bank feature is one of the areas I am looking into right 
> now. Somehow, TS-DOS is able to determine if the drive is a TPPD2 and then 
> the Bank feature is turned on. According to the manual, 200k is always 
> available regardless of what bank you are in. It's not split 100k/100k. Each 
> bank appears to have its own file allocation table with a maximum of 40 
> filenames.
> 
> I have not had much time with the drive yet but I'm curious if I can emulate 
> the bank feature in mComm to have two directories supported at the same time. 
> So in TEXT or BASIC a file save such as "0:XXXXXX.DO" would go to the active 
> directory and "1:XXXXXX.DO" would point to an alternate location.
> 
> I don't know if it's possible but I plan to look into it.
> 
> Kurt
> -----Original Message-----
> From: M100 [mailto:m100-boun...@lists.bitchin100.com] On Behalf Of Gary Weber
> Sent: Tuesday, August 08, 2017 12:33 AM
> To: m...@bitchin100.com
> Subject: Re: [M100] 3.5" Media
> 
>> 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.  ;-)
> 
> But wait!  This is the story that I believed for years, as it was told to me 
> by *someone* out there.  And having not ever closely examined the drive to 
> see if there's *actually* two read/write heads, I
> believed it.   Until tonight.
> 
> The "Bank" feature definitely accesses the second 100k, but smack me upside 
> the head please:  There's only one drive head!  So please disregard 
> everything I said before; apparently the 200k format is just
> higher density (closer track spacing??).   All these years, believing
> something incorrect...
> 
> Feel free to commence fantasizing about 3.5" flippy-floppies once again.  ;-)
> 
> 
> 
> On Mon, Aug 7, 2017 at 9:39 PM, Gary Weber <m100l...@gweber.org> 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> 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] On Behalf Of 
>>> Brian White
>>> Sent: Monday, August 07, 2017 4:41 PM
>>> To: 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
>>> 
>>> Jump to page 41
>>> 
>>> http://www.colorcomputerarchive.com/coco/Documents/Radio%20Shack%20Ca
>>> talogs/Tandy%20Computer%20Catalog%20and%20Software%20Reference%20Guid
>>> e%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 <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>
>>> 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
>>> 
>>> 
>> 
>> 
> 
> 
> 
> --
> Gary Weber
> g...@web8201.com
> 

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