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:[email protected]] On Behalf Of Gary Weber Sent: Tuesday, August 08, 2017 12:33 AM To: [email protected] 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 <[email protected]> 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 <[email protected]> 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:[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%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 <[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]> >> 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] >> >> > > -- Gary Weber [email protected]
