[M100] REX: Question about REXMGR

[Peter Noeth]

  I was just reading the REX Manager User Guide (
http://bitchin100.com/wiki/index.php?title=REX_Manager_User_Guide) and
found that the screen shot seems quite out of date (v4.5). Although the
operation described seemed to match the current version (v4.9), it does not
explain what the "reverse video" 'M' on the first line just to the right of
the version number means on v4.9.

  I found nothing about this in the built in "Help" [F1] either.

  I am making additions to my "Quick Reference" card on REX, so was
wondering what the "M" means.

Regards,

Peter

Re: [M100] REX: Downloading OPTROM images

[Mike Stein]

I don't suppose you could just power it from Vb so it retains its settings 
unless specifically reset?
  - Original Message - 
  From: Stephen Adolph 
  To: m...@bitchin100.com 
  Sent: Monday, March 25, 2019 8:06 PM
  Subject: Re: [M100] REX: Downloading OPTROM images


  Peter did you worry about power up flip flop state?


  If So what is the circuit you used?  Thx.


  On Monday, March 25, 2019, Peter Noeth  wrote:

Steven,


  The Dual ROM/ 128k RAM Memory system is of my own design. Basically the 
standard ROM / RAM was removed and replaced with a new daughter board. It 
allows selecting RAM in 32k banks (4) and system ROM by using the BASIC OUT x,y 
statement. I had this in my T102 for about 2 years before I got the REX.


  Other than the REX's mode of identifying the current OPTROM image by over 
writing the Microsoft copyright on the main Menu (I use this space to identify 
which ROM I am using), it works just fine. The second ROM contained changes for 
the character generator to better match my Sekio printer. Plus they both 
contained the Y2K date fix and they both contain the RAM bank switch code.


  Also LaddieAlpha is what I used to download the Polar Systems ROM II / 
Cleuseau image to REX. It worked correctly on a WinXP system.


   I am still studying the TS-DOS / TPDD interface, now that I have it. I 
wrote my own file transfer system decades ago, so will see if I want to use the 
TPDD interface from now on.


Regards,


Peter


< snip >
Message: 12
Date: Mon, 25 Mar 2019 06:14:55 -0400
From: Stephen Adolph 
To: m...@bitchin100.com
Subject: Re: [M100] REX: Downloading OPTROM images
Message-ID:

Content-Type: text/plain; charset="utf-8"

what dual rom 128k ram memory system?  very interesting!  I'm interested to
learn more. might be a conflict however with REX, depending on the
details...

On Sun, Mar 24, 2019 at 10:39 PM Peter Noeth  wrote:

> Group,
>
>   I purchased a REX at Tandy Assembly 2018, but am just now getting around
> to testing it with my T102 Dual ROM/128KB RAM Memory System.
>
>   The REX Wiki instructions tell of needing a TPDD PC emulator (I have no
> TPDD device) but it does not indicate what program to use, or where to
> download it. I believe that either LaddieCon or LaddieAlpha is what I 
need.
> But after searching for them, I found a download link on the LaddieCon 
Wiki
> (on http://bitchin100.com/wiki/index.php?title=LaddieCon) that when the
> programs download, the Win7 Smart Screen Filter reports them as unsafe.
>
>   Is this the correct place to download the files? If so, are they really
> unsafe?
>
> Regards,
>
> Peter
>
< snip >

Re: [M100] REX: Downloading OPTROM images

[Mike Stein]

I've been thinking about a 2MB RAM option ROM replacement, which would yield 64 
pages of either RAM images or paged file space; I suppose I could add an 
alternate system ROM while I'm at it ;-)

m
  - Original Message - 
  From: Stephen Adolph 
  To: m...@bitchin100.com 
  Sent: Monday, March 25, 2019 8:06 PM
  Subject: Re: [M100] REX: Downloading OPTROM images


  Peter did you worry about power up flip flop state?


  If So what is the circuit you used?  Thx.


  On Monday, March 25, 2019, Peter Noeth  wrote:

Steven,


  The Dual ROM/ 128k RAM Memory system is of my own design. Basically the 
standard ROM / RAM was removed and replaced with a new daughter board. It 
allows selecting RAM in 32k banks (4) and system ROM by using the BASIC OUT x,y 
statement. I had this in my T102 for about 2 years before I got the REX.


  Other than the REX's mode of identifying the current OPTROM image by over 
writing the Microsoft copyright on the main Menu (I use this space to identify 
which ROM I am using), it works just fine. The second ROM contained changes for 
the character generator to better match my Sekio printer. Plus they both 
contained the Y2K date fix and they both contain the RAM bank switch code.


  Also LaddieAlpha is what I used to download the Polar Systems ROM II / 
Cleuseau image to REX. It worked correctly on a WinXP system.


   I am still studying the TS-DOS / TPDD interface, now that I have it. I 
wrote my own file transfer system decades ago, so will see if I want to use the 
TPDD interface from now on.


Regards,


Peter


< snip >
Message: 12
Date: Mon, 25 Mar 2019 06:14:55 -0400
From: Stephen Adolph 
To: m...@bitchin100.com
Subject: Re: [M100] REX: Downloading OPTROM images
Message-ID:

Content-Type: text/plain; charset="utf-8"

what dual rom 128k ram memory system?  very interesting!  I'm interested to
learn more. might be a conflict however with REX, depending on the
details...

On Sun, Mar 24, 2019 at 10:39 PM Peter Noeth  wrote:

> Group,
>
>   I purchased a REX at Tandy Assembly 2018, but am just now getting around
> to testing it with my T102 Dual ROM/128KB RAM Memory System.
>
>   The REX Wiki instructions tell of needing a TPDD PC emulator (I have no
> TPDD device) but it does not indicate what program to use, or where to
> download it. I believe that either LaddieCon or LaddieAlpha is what I 
need.
> But after searching for them, I found a download link on the LaddieCon 
Wiki
> (on http://bitchin100.com/wiki/index.php?title=LaddieCon) that when the
> programs download, the Win7 Smart Screen Filter reports them as unsafe.
>
>   Is this the correct place to download the files? If so, are they really
> unsafe?
>
> Regards,
>
> Peter
>
< snip >

Re: [M100] REX: Downloading OPTROM images

[Stephen Adolph]

Peter did you worry about power up flip flop state?

If So what is the circuit you used?  Thx.


On Monday, March 25, 2019, Peter Noeth  wrote:

> Steven,
>
>   The Dual ROM/ 128k RAM Memory system is of my own design. Basically the
> standard ROM / RAM was removed and replaced with a new daughter board. It
> allows selecting RAM in 32k banks (4) and system ROM by using the BASIC OUT
> x,y statement. I had this in my T102 for about 2 years before I got the REX.
>
>   Other than the REX's mode of identifying the current OPTROM image by
> over writing the Microsoft copyright on the main Menu (I use this space to
> identify which ROM I am using), it works just fine. The second ROM
> contained changes for the character generator to better match my Sekio
> printer. Plus they both contained the Y2K date fix and they both contain
> the RAM bank switch code.
>
>   Also LaddieAlpha is what I used to download the Polar Systems ROM II /
> Cleuseau image to REX. It worked correctly on a WinXP system.
>
>I am still studying the TS-DOS / TPDD interface, now that I have it. I
> wrote my own file transfer system decades ago, so will see if I want to use
> the TPDD interface from now on.
>
> Regards,
>
> Peter
>
> < snip >
> Message: 12
> Date: Mon, 25 Mar 2019 06:14:55 -0400
> From: Stephen Adolph 
> To: m...@bitchin100.com
> Subject: Re: [M100] REX: Downloading OPTROM images
> Message-ID:
>  csd1rcbw7...@mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> what dual rom 128k ram memory system?  very interesting!  I'm interested to
> learn more. might be a conflict however with REX, depending on the
> details...
>
> On Sun, Mar 24, 2019 at 10:39 PM Peter Noeth  wrote:
>
> > Group,
> >
> >   I purchased a REX at Tandy Assembly 2018, but am just now getting
> around
> > to testing it with my T102 Dual ROM/128KB RAM Memory System.
> >
> >   The REX Wiki instructions tell of needing a TPDD PC emulator (I have no
> > TPDD device) but it does not indicate what program to use, or where to
> > download it. I believe that either LaddieCon or LaddieAlpha is what I
> need.
> > But after searching for them, I found a download link on the LaddieCon
> Wiki
> > (on http://bitchin100.com/wiki/index.php?title=LaddieCon) that when the
> > programs download, the Win7 Smart Screen Filter reports them as unsafe.
> >
> >   Is this the correct place to download the files? If so, are they really
> > unsafe?
> >
> > Regards,
> >
> > Peter
> >
> < snip >
>

Re: [M100] REX: Downloading OPTROM images

[Stephen Adolph]

Wow very nice.
That makes great sense. I misinterpreted the "rom" statement.  I thought
'option ROM'... not main rom.
very cool.

On Mon, Mar 25, 2019 at 6:31 PM Peter Noeth  wrote:

> Steven,
>
>   The Dual ROM/ 128k RAM Memory system is of my own design. Basically the
> standard ROM / RAM was removed and replaced with a new daughter board. It
> allows selecting RAM in 32k banks (4) and system ROM by using the BASIC OUT
> x,y statement. I had this in my T102 for about 2 years before I got the REX.
>
>   Other than the REX's mode of identifying the current OPTROM image by
> over writing the Microsoft copyright on the main Menu (I use this space to
> identify which ROM I am using), it works just fine. The second ROM
> contained changes for the character generator to better match my Sekio
> printer. Plus they both contained the Y2K date fix and they both contain
> the RAM bank switch code.
>
>   Also LaddieAlpha is what I used to download the Polar Systems ROM II /
> Cleuseau image to REX. It worked correctly on a WinXP system.
>
>I am still studying the TS-DOS / TPDD interface, now that I have it. I
> wrote my own file transfer system decades ago, so will see if I want to use
> the TPDD interface from now on.
>
> Regards,
>
> Peter
>
> < snip >
> Message: 12
> Date: Mon, 25 Mar 2019 06:14:55 -0400
> From: Stephen Adolph 
> To: m...@bitchin100.com
> Subject: Re: [M100] REX: Downloading OPTROM images
> Message-ID:
>  hcsd1rcbw7...@mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> what dual rom 128k ram memory system?  very interesting!  I'm interested to
> learn more. might be a conflict however with REX, depending on the
> details...
>
> On Sun, Mar 24, 2019 at 10:39 PM Peter Noeth  wrote:
>
> > Group,
> >
> >   I purchased a REX at Tandy Assembly 2018, but am just now getting
> around
> > to testing it with my T102 Dual ROM/128KB RAM Memory System.
> >
> >   The REX Wiki instructions tell of needing a TPDD PC emulator (I have no
> > TPDD device) but it does not indicate what program to use, or where to
> > download it. I believe that either LaddieCon or LaddieAlpha is what I
> need.
> > But after searching for them, I found a download link on the LaddieCon
> Wiki
> > (on http://bitchin100.com/wiki/index.php?title=LaddieCon) that when the
> > programs download, the Win7 Smart Screen Filter reports them as unsafe.
> >
> >   Is this the correct place to download the files? If so, are they really
> > unsafe?
> >
> > Regards,
> >
> > Peter
> >
> < snip >
>

Re: [M100] REX: Downloading OPTROM images

[Peter Noeth]

Steven,

  The Dual ROM/ 128k RAM Memory system is of my own design. Basically the
standard ROM / RAM was removed and replaced with a new daughter board. It
allows selecting RAM in 32k banks (4) and system ROM by using the BASIC OUT
x,y statement. I had this in my T102 for about 2 years before I got the REX.

  Other than the REX's mode of identifying the current OPTROM image by over
writing the Microsoft copyright on the main Menu (I use this space to
identify which ROM I am using), it works just fine. The second ROM
contained changes for the character generator to better match my Sekio
printer. Plus they both contained the Y2K date fix and they both contain
the RAM bank switch code.

  Also LaddieAlpha is what I used to download the Polar Systems ROM II /
Cleuseau image to REX. It worked correctly on a WinXP system.

   I am still studying the TS-DOS / TPDD interface, now that I have it. I
wrote my own file transfer system decades ago, so will see if I want to use
the TPDD interface from now on.

Regards,

Peter

< snip >
Message: 12
Date: Mon, 25 Mar 2019 06:14:55 -0400
From: Stephen Adolph 
To: m...@bitchin100.com
Subject: Re: [M100] REX: Downloading OPTROM images
Message-ID:

Content-Type: text/plain; charset="utf-8"

what dual rom 128k ram memory system?  very interesting!  I'm interested to
learn more. might be a conflict however with REX, depending on the
details...

On Sun, Mar 24, 2019 at 10:39 PM Peter Noeth  wrote:

> Group,
>
>   I purchased a REX at Tandy Assembly 2018, but am just now getting around
> to testing it with my T102 Dual ROM/128KB RAM Memory System.
>
>   The REX Wiki instructions tell of needing a TPDD PC emulator (I have no
> TPDD device) but it does not indicate what program to use, or where to
> download it. I believe that either LaddieCon or LaddieAlpha is what I
need.
> But after searching for them, I found a download link on the LaddieCon
Wiki
> (on http://bitchin100.com/wiki/index.php?title=LaddieCon) that when the
> programs download, the Win7 Smart Screen Filter reports them as unsafe.
>
>   Is this the correct place to download the files? If so, are they really
> unsafe?
>
> Regards,
>
> Peter
>
< snip >

Re: [M100] question regarding floppy disks.

[Stephen Adolph]

yes, I wrote that backwards.  but thanks I feel like I got all my questions
sorted.


On Mon, Mar 25, 2019 at 12:58 PM Mike Stein  wrote:

> > So,  hole "covered" tells the drive to write at 2x the speed!
> Interesting, and makes sense.
>
> Well, no, hole "covered" signals 250Kbps low write current DD so if
> anything it's the other way around (unless my aging brain is even more
> confused than usual).
>
> But I think the actual data rate is determined by the controller when
> writing, and the disk data when reading, so it will always be 250Kbps.
>
> What causes the problem IMO is that the drive electronics are 'tuned' to
> the wrong frequency when it's reading 250Kbps while set to 500; some of the
> newer 'intelligent' drives may even detect an error and suppress the ready
> or index signals when they see this situation.
>
>
> - Original Message -
> From: Stephen Adolph
> To: m...@bitchin100.com
> Sent: Monday, March 25, 2019 12:29 PM
> Subject: Re: [M100] question regarding floppy disks.
>
>
> Thanks Mike, that must be the answer.
>
>
> I notice that the formatting process for an HD disk in an HD drive on the
> COCO fails after the first pass on the disk formatting run.
> That must mean - reading back to verify the format is failing.
>
>
> So,  hole "covered" tells the drive to write at 2x the speed!
> Interesting, and makes sense.
>
>
> and you are right, I am buying a couple of boxes of DD disks locally.
>
>
>
>
>
>
> On Mon, Mar 25, 2019 at 12:23 PM Mike Stein  wrote:
>
> The difference in coercivity between DD and HD 3.5" diskettes is actually
> relatively small, ~660 vs. ~720 Oersteds, compared to the much larger 290
> vs. 660 difference of 5.25" diskettes.
>
> But the thickness of the coating is also different, HD being less than
> half that of DD, and different materials are used with the HD having a
> finer granularity.
>
> Nevertheless, you can usually get away with using HD diskettes at DD (with
> the hole covered if using an HD drive), although it's not quite as reliable
> as using the proper media, especially regarding long-term data retention
> (probably because the lower DD write current makes them more susceptible to
> being erased); even the other way around often works, i.e. a DD diskette
> with a hole punched at HD, although this is even less reliable.
>
> Anecdotally it seems that 3.5" HD diskettes in general have become
> somewhat unreliable, even used at HD, which may at least partially account
> for folks having issues using them at DD.
>
> But I think we're missing the more important issue; the reason for all
> these differences is to squeeze more bits per inch on a track; unlike
> 5.25", 3.5" diskettes all have 80 tracks and run at the same 300 RPM, so of
> course this means that data  will normally be written and read at twice the
> rate in HD mode (500Kbps) than at the DD rate (250Kbps).
>
> I assume that the CoCo controller only transfers data at 250Kbps whereas
> with the HD hole uncovered the drive will expect to see data at 500Kbps
> (and use HD write current) and I suspect that's why Steve's having trouble.
>
> 3.5" DD diskettes are still around; why not use the right media in the
> first place.
>
> m
> - Original Message -
> From: Kurt McCullum
> To: m100@lists.bitchin100.com
> Sent: Monday, March 25, 2019 11:02 AM
> Subject: Re: [M100] question regarding floppy disks.
>
>
> Yeah that does sound strange. And I agree, the drive 'should' switch based
> on the hole in the disk. Does it format to 720 or 1.44 when the hole is
> covered?
>
>
> On Mon, Mar 25, 2019, at 7:37 AM, Stephen Adolph wrote:
>
> Kurt, agree with everything you have said.
>
>
>
> The odd thing is-
>
>
>
> * using an HD disk in an DD/HD drive, and covering the hole with tape,
> would seem to be BAD
>
> ---> because you are telling the drive to use the wrong current settings
> for the actual disk media.
>
>
>
> However, this is apparently the way to make my system functional.
>
>
>
> so, strange.  I would have thought it would be the opposite - let the
> drive decide what current to use, matched to the "cookie".
>
>
>
>
>
> On Mon, Mar 25, 2019 at 10:19 AM Kurt McCullum  wrote:
>
>
>
> The magnetic coercivity on HD disks is different than on regular disks. It
> requires more energy to lay down the tracks. If you start with a blank HD
> disk rather than a pre-formatted disk then you have a better chance. That's
> because once the HD tracks are laid down, you need to erase them for your
> new format. If your drive doesn't have enough energy to completely erase
> the existing track, it wont work. 720k disks have a lower coercivity and
> therefore work with either a 720k or 1.44mb drive. A 1.44 drive has a
> sensor for the open hole and when it sees that hole, it will use a higher
> level of write energy to properly work with the media. When that hole is
> covered, it will use a lower level which is what the 720k media is looking
> for. Though I do remember that formatting a 720k disk in a 

Re: [M100] question regarding floppy disks.

[Mike Stein]

> So,  hole "covered" tells the drive to write at 2x the speed!  Interesting, 
> and makes sense.

Well, no, hole "covered" signals 250Kbps low write current DD so if anything 
it's the other way around (unless my aging brain is even more confused than 
usual).

But I think the actual data rate is determined by the controller when writing, 
and the disk data when reading, so it will always be 250Kbps.

What causes the problem IMO is that the drive electronics are 'tuned' to the 
wrong frequency when it's reading 250Kbps while set to 500; some of the newer 
'intelligent' drives may even detect an error and suppress the ready or index 
signals when they see this situation.


- Original Message - 
From: Stephen Adolph 
To: m...@bitchin100.com 
Sent: Monday, March 25, 2019 12:29 PM
Subject: Re: [M100] question regarding floppy disks.


Thanks Mike, that must be the answer.


I notice that the formatting process for an HD disk in an HD drive on the COCO 
fails after the first pass on the disk formatting run.
That must mean - reading back to verify the format is failing.


So,  hole "covered" tells the drive to write at 2x the speed!  Interesting, and 
makes sense.


and you are right, I am buying a couple of boxes of DD disks locally.






On Mon, Mar 25, 2019 at 12:23 PM Mike Stein  wrote:

The difference in coercivity between DD and HD 3.5" diskettes is actually 
relatively small, ~660 vs. ~720 Oersteds, compared to the much larger 290 vs. 
660 difference of 5.25" diskettes.

But the thickness of the coating is also different, HD being less than half 
that of DD, and different materials are used with the HD having a finer 
granularity.

Nevertheless, you can usually get away with using HD diskettes at DD (with the 
hole covered if using an HD drive), although it's not quite as reliable as 
using the proper media, especially regarding long-term data retention (probably 
because the lower DD write current makes them more susceptible to being 
erased); even the other way around often works, i.e. a DD diskette with a hole 
punched at HD, although this is even less reliable.

Anecdotally it seems that 3.5" HD diskettes in general have become somewhat 
unreliable, even used at HD, which may at least partially account for folks 
having issues using them at DD.

But I think we're missing the more important issue; the reason for all these 
differences is to squeeze more bits per inch on a track; unlike 5.25", 3.5" 
diskettes all have 80 tracks and run at the same 300 RPM, so of course this 
means that data  will normally be written and read at twice the rate in HD mode 
(500Kbps) than at the DD rate (250Kbps).

I assume that the CoCo controller only transfers data at 250Kbps whereas with 
the HD hole uncovered the drive will expect to see data at 500Kbps (and use HD 
write current) and I suspect that's why Steve's having trouble.

3.5" DD diskettes are still around; why not use the right media in the first 
place.

m
- Original Message - 
From: Kurt McCullum 
To: m100@lists.bitchin100.com 
Sent: Monday, March 25, 2019 11:02 AM
Subject: Re: [M100] question regarding floppy disks.


Yeah that does sound strange. And I agree, the drive 'should' switch based on 
the hole in the disk. Does it format to 720 or 1.44 when the hole is covered?


On Mon, Mar 25, 2019, at 7:37 AM, Stephen Adolph wrote:

Kurt, agree with everything you have said.



The odd thing is-



* using an HD disk in an DD/HD drive, and covering the hole with tape, would 
seem to be BAD

---> because you are telling the drive to use the wrong current settings for 
the actual disk media.



However, this is apparently the way to make my system functional.



so, strange.  I would have thought it would be the opposite - let the drive 
decide what current to use, matched to the "cookie".





On Mon, Mar 25, 2019 at 10:19 AM Kurt McCullum  wrote:



The magnetic coercivity on HD disks is different than on regular disks. It 
requires more energy to lay down the tracks. If you start with a blank HD disk 
rather than a pre-formatted disk then you have a better chance. That's because 
once the HD tracks are laid down, you need to erase them for your new format. 
If your drive doesn't have enough energy to completely erase the existing 
track, it wont work. 720k disks have a lower coercivity and therefore work with 
either a 720k or 1.44mb drive. A 1.44 drive has a sensor for the open hole and 
when it sees that hole, it will use a higher level of write energy to properly 
work with the media. When that hole is covered, it will use a lower level which 
is what the 720k media is looking for. Though I do remember that formatting a 
720k disk in a 1.44mb drive didn't always work when going back to a 720k drive. 



Not sure about the Coco drive, but my TPDD2 does not work reliably with HD 
disks. I have only been able to format one properly and it had data failure 
shortly after.



Kurt



On Sun, Mar 24, 2019, at 6:32 PM, Stephen Adolph wrote:

Re: [M100] question regarding floppy disks.

[MikeS]

... But it's actually 256 bytes/sector, 18 sectors/track, 35 tracks ...

;-)
  - Original Message - 
  From: Mike Stein 
  To: m...@bitchin100.com 
  Sent: Monday, March 25, 2019 12:28 PM
  Subject: Re: [M100] question regarding floppy disks.


  Sounds similar to the original IBM 5.25" format, single-sided, 512 
bytes/sector, 8 sectors/track, 40 tracks, 250Kbps.
- Original Message - 
From: Stephen Adolph 
To: m...@bitchin100.com 
Sent: Monday, March 25, 2019 11:54 AM
Subject: Re: [M100] question regarding floppy disks.


when attached to a CoCo, you get 160k.


On Mon, Mar 25, 2019 at 11:02 AM Kurt McCullum  wrote:

  Yeah that does sound strange. And I agree, the drive 'should' switch 
based on the hole in the disk. Does it format to 720 or 1.44 when the hole is 
covered?


  On Mon, Mar 25, 2019, at 7:37 AM, Stephen Adolph wrote:

Kurt, agree with everything you have said.



The odd thing is-



* using an HD disk in an DD/HD drive, and covering the hole with tape, 
would seem to be BAD

---> because you are telling the drive to use the wrong current 
settings for the actual disk media.



However, this is apparently the way to make my system functional.



so, strange.  I would have thought it would be the opposite - let the 
drive decide what current to use, matched to the "cookie".





On Mon, Mar 25, 2019 at 10:19 AM Kurt McCullum  
wrote:



  The magnetic coercivity on HD disks is different than on regular 
disks. It requires more energy to lay down the tracks. If you start with a 
blank HD disk rather than a pre-formatted disk then you have a better chance. 
That's because once the HD tracks are laid down, you need to erase them for 
your new format. If your drive doesn't have enough energy to completely erase 
the existing track, it wont work. 720k disks have a lower coercivity and 
therefore work with either a 720k or 1.44mb drive. A 1.44 drive has a sensor 
for the open hole and when it sees that hole, it will use a higher level of 
write energy to properly work with the media. When that hole is covered, it 
will use a lower level which is what the 720k media is looking for. Though I do 
remember that formatting a 720k disk in a 1.44mb drive didn't always work when 
going back to a 720k drive. 



  Not sure about the Coco drive, but my TPDD2 does not work reliably 
with HD disks. I have only been able to format one properly and it had data 
failure shortly after.



  Kurt



  On Sun, Mar 24, 2019, at 6:32 PM, Stephen Adolph wrote:

interestingly,



Yes, if I take an HD disk, and tape over the hole to make it appear 
to be a DD disk, then it works.



But why?



the floppy is capable of both formats...



On Sun, Mar 24, 2019 at 7:39 PM Mike Stein  
wrote:



  Have you tried closing the HD sense hole with a piece of tape or 
similar?

- Original Message -

From: Stephen Adolph

To: m...@bitchin100.com

Sent: Sunday, March 24, 2019 6:08 PM

Subject: Re: [M100] question regarding floppy disks.



the Coco is using it's standard controller



When issuing the DSKINI 0 command the coco tries to format for 
180kB.



The combination of 

(Coco, std controller, PC 1.44MB drive + a 720kB dd floppy) 
works



whereas

(Coco, std controller, PC 1.44MB drive + a 1.44MBB hd floppy) 
does not work



this is something I don't understand!







On Sun, Mar 24, 2019 at 5:42 PM Gregory McGill 
 wrote:

  likely the floppy controller doesn't support 80 tracks or 
high density..  most of the controllers of the era are ds/sd 40 track or dsdd 
40 track..   are you able to format 720k? ds/dd 80 track? 



  Greg



  On Sun, Mar 24, 2019 at 2:38 PM Stephen Adolph 
 wrote:

I'll start by saying this isn't an M100 or TPDD discussion, 
but just looking to understand something.



I have a Tandy Coco3 with a 3.5 inch floppy drive.  The 
drive is a standard PC drive and it is working well.



Seems though that I cannot use 1.44 MB floppies in that 
drive. They don't seem to want to format.



I really don't understand where the problem could be.

- the drive and the floppy are compatible

- the disk is known good and formats at 1.44MB in a PC

- if it can support 135 TPI, why can't it support 35 TPI?



Does anyone know what's going on?



thx

Steve

Re: [M100] question regarding floppy disks.

[Stephen Adolph]

Thanks Mike, that must be the answer.

I notice that the formatting process for an HD disk in an HD drive on the
COCO fails after the first pass on the disk formatting run.
That must mean - reading back to verify the format is failing.

So,  hole "covered" tells the drive to write at 2x the speed!  Interesting,
and makes sense.

and you are right, I am buying a couple of boxes of DD disks locally.



On Mon, Mar 25, 2019 at 12:23 PM Mike Stein  wrote:

> The difference in coercivity between DD and HD 3.5" diskettes is actually
> relatively small, ~660 vs. ~720 Oersteds, compared to the much larger 290
> vs. 660 difference of 5.25" diskettes.
>
> But the thickness of the coating is also different, HD being less than
> half that of DD, and different materials are used with the HD having a
> finer granularity.
>
> Nevertheless, you can usually get away with using HD diskettes at DD (with
> the hole covered if using an HD drive), although it's not quite as reliable
> as using the proper media, especially regarding long-term data retention
> (probably because the lower DD write current makes them more susceptible to
> being erased); even the other way around often works, i.e. a DD diskette
> with a hole punched at HD, although this is even less reliable.
>
> Anecdotally it seems that 3.5" HD diskettes in general have become
> somewhat unreliable, even used at HD, which may at least partially account
> for folks having issues using them at DD.
>
> But I think we're missing the more important issue; the reason for all
> these differences is to squeeze more bits per inch on a track; unlike
> 5.25", 3.5" diskettes all have 80 tracks and run at the same 300 RPM, so of
> course this means that data  will normally be written and read at twice the
> rate in HD mode (500Kbps) than at the DD rate (250Kbps).
>
> I assume that the CoCo controller only transfers data at 250Kbps whereas
> with the HD hole uncovered the drive will expect to see data at 500Kbps
> (and use HD write current) and I suspect that's why Steve's having trouble.
>
> 3.5" DD diskettes are still around; why not use the right media in the
> first place.
>
> m
>
> - Original Message -
> *From:* Kurt McCullum 
> *To:* m100@lists.bitchin100.com
> *Sent:* Monday, March 25, 2019 11:02 AM
> *Subject:* Re: [M100] question regarding floppy disks.
>
> Yeah that does sound strange. And I agree, the drive 'should' switch based
> on the hole in the disk. Does it format to 720 or 1.44 when the hole is
> covered?
>
> On Mon, Mar 25, 2019, at 7:37 AM, Stephen Adolph wrote:
>
> Kurt, agree with everything you have said.
>
> The odd thing is-
>
> * using an HD disk in an DD/HD drive, and covering the hole with tape,
> would seem to be BAD
> ---> because you are telling the drive to use the wrong current settings
> for the actual disk media.
>
> However, this is apparently the way to make my system functional.
>
> so, strange.  I would have thought it would be the opposite - let the
> drive decide what current to use, matched to the "cookie".
>
>
> On Mon, Mar 25, 2019 at 10:19 AM Kurt McCullum  wrote:
>
>
> The magnetic coercivity on HD disks is different than on regular disks. It
> requires more energy to lay down the tracks. If you start with a blank HD
> disk rather than a pre-formatted disk then you have a better chance. That's
> because once the HD tracks are laid down, you need to erase them for your
> new format. If your drive doesn't have enough energy to completely erase
> the existing track, it wont work. 720k disks have a lower coercivity and
> therefore work with either a 720k or 1.44mb drive. A 1.44 drive has a
> sensor for the open hole and when it sees that hole, it will use a higher
> level of write energy to properly work with the media. When that hole is
> covered, it will use a lower level which is what the 720k media is looking
> for. Though I do remember that formatting a 720k disk in a 1.44mb drive
> didn't always work when going back to a 720k drive.
>
> Not sure about the Coco drive, but my TPDD2 does not work reliably with HD
> disks. I have only been able to format one properly and it had data failure
> shortly after.
>
> Kurt
>
> On Sun, Mar 24, 2019, at 6:32 PM, Stephen Adolph wrote:
>
> interestingly,
>
> Yes, if I take an HD disk, and tape over the hole to make it appear to be
> a DD disk, then it works.
>
> But why?
>
> the floppy is capable of both formats...
>
> On Sun, Mar 24, 2019 at 7:39 PM Mike Stein  wrote:
>
>
> Have you tried closing the HD sense hole with a piece of tape or similar?
>
> - Original Message -
> *From:* Stephen Adolph 
> *To:* m...@bitchin100.com
> *Sent:* Sunday, March 24, 2019 6:08 PM
> *Subject:* Re: [M100] question regarding floppy disks.
>
> the Coco is using it's standard controller
>
> When issuing the DSKINI 0 command the coco tries to format for 180kB.
>
> The combination of
> (Coco, std controller, PC 1.44MB drive + a 720kB dd floppy) works
>
> whereas
> (Coco, std controller, PC 1.44MB 

Re: [M100] question regarding floppy disks.

[Mike Stein]

Sounds similar to the original IBM 5.25" format, single-sided, 512 
bytes/sector, 8 sectors/track, 40 tracks, 250Kbps.
  - Original Message - 
  From: Stephen Adolph 
  To: m...@bitchin100.com 
  Sent: Monday, March 25, 2019 11:54 AM
  Subject: Re: [M100] question regarding floppy disks.


  when attached to a CoCo, you get 160k.


  On Mon, Mar 25, 2019 at 11:02 AM Kurt McCullum  wrote:

Yeah that does sound strange. And I agree, the drive 'should' switch based 
on the hole in the disk. Does it format to 720 or 1.44 when the hole is covered?


On Mon, Mar 25, 2019, at 7:37 AM, Stephen Adolph wrote:

  Kurt, agree with everything you have said.



  The odd thing is-



  * using an HD disk in an DD/HD drive, and covering the hole with tape, 
would seem to be BAD

  ---> because you are telling the drive to use the wrong current settings 
for the actual disk media.



  However, this is apparently the way to make my system functional.



  so, strange.  I would have thought it would be the opposite - let the 
drive decide what current to use, matched to the "cookie".





  On Mon, Mar 25, 2019 at 10:19 AM Kurt McCullum  wrote:



The magnetic coercivity on HD disks is different than on regular disks. 
It requires more energy to lay down the tracks. If you start with a blank HD 
disk rather than a pre-formatted disk then you have a better chance. That's 
because once the HD tracks are laid down, you need to erase them for your new 
format. If your drive doesn't have enough energy to completely erase the 
existing track, it wont work. 720k disks have a lower coercivity and therefore 
work with either a 720k or 1.44mb drive. A 1.44 drive has a sensor for the open 
hole and when it sees that hole, it will use a higher level of write energy to 
properly work with the media. When that hole is covered, it will use a lower 
level which is what the 720k media is looking for. Though I do remember that 
formatting a 720k disk in a 1.44mb drive didn't always work when going back to 
a 720k drive. 



Not sure about the Coco drive, but my TPDD2 does not work reliably with 
HD disks. I have only been able to format one properly and it had data failure 
shortly after.



Kurt



On Sun, Mar 24, 2019, at 6:32 PM, Stephen Adolph wrote:

  interestingly,



  Yes, if I take an HD disk, and tape over the hole to make it appear 
to be a DD disk, then it works.



  But why?



  the floppy is capable of both formats...



  On Sun, Mar 24, 2019 at 7:39 PM Mike Stein  
wrote:



Have you tried closing the HD sense hole with a piece of tape or 
similar?

  - Original Message -

  From: Stephen Adolph

  To: m...@bitchin100.com

  Sent: Sunday, March 24, 2019 6:08 PM

  Subject: Re: [M100] question regarding floppy disks.



  the Coco is using it's standard controller



  When issuing the DSKINI 0 command the coco tries to format for 
180kB.



  The combination of 

  (Coco, std controller, PC 1.44MB drive + a 720kB dd floppy) works



  whereas

  (Coco, std controller, PC 1.44MB drive + a 1.44MBB hd floppy) 
does not work



  this is something I don't understand!







  On Sun, Mar 24, 2019 at 5:42 PM Gregory McGill 
 wrote:

likely the floppy controller doesn't support 80 tracks or high 
density..  most of the controllers of the era are ds/sd 40 track or dsdd 40 
track..   are you able to format 720k? ds/dd 80 track? 



Greg



On Sun, Mar 24, 2019 at 2:38 PM Stephen Adolph 
 wrote:

  I'll start by saying this isn't an M100 or TPDD discussion, 
but just looking to understand something.



  I have a Tandy Coco3 with a 3.5 inch floppy drive.  The drive 
is a standard PC drive and it is working well.



  Seems though that I cannot use 1.44 MB floppies in that 
drive. They don't seem to want to format.



  I really don't understand where the problem could be.

  - the drive and the floppy are compatible

  - the disk is known good and formats at 1.44MB in a PC

  - if it can support 135 TPI, why can't it support 35 TPI?



  Does anyone know what's going on?



  thx

  Steve

Re: [M100] question regarding floppy disks.

[Mike Stein]

The difference in coercivity between DD and HD 3.5" diskettes is actually 
relatively small, ~660 vs. ~720 Oersteds, compared to the much larger 290 vs. 
660 difference of 5.25" diskettes.

But the thickness of the coating is also different, HD being less than half 
that of DD, and different materials are used with the HD having a finer 
granularity.

Nevertheless, you can usually get away with using HD diskettes at DD (with the 
hole covered if using an HD drive), although it's not quite as reliable as 
using the proper media, especially regarding long-term data retention (probably 
because the lower DD write current makes them more susceptible to being 
erased); even the other way around often works, i.e. a DD diskette with a hole 
punched at HD, although this is even less reliable.

Anecdotally it seems that 3.5" HD diskettes in general have become somewhat 
unreliable, even used at HD, which may at least partially account for folks 
having issues using them at DD.

But I think we're missing the more important issue; the reason for all these 
differences is to squeeze more bits per inch on a track; unlike 5.25", 3.5" 
diskettes all have 80 tracks and run at the same 300 RPM, so of course this 
means that data  will normally be written and read at twice the rate in HD mode 
(500Kbps) than at the DD rate (250Kbps).

I assume that the CoCo controller only transfers data at 250Kbps whereas with 
the HD hole uncovered the drive will expect to see data at 500Kbps (and use HD 
write current) and I suspect that's why Steve's having trouble.

3.5" DD diskettes are still around; why not use the right media in the first 
place.

m
  - Original Message - 
  From: Kurt McCullum 
  To: m100@lists.bitchin100.com 
  Sent: Monday, March 25, 2019 11:02 AM
  Subject: Re: [M100] question regarding floppy disks.


  Yeah that does sound strange. And I agree, the drive 'should' switch based on 
the hole in the disk. Does it format to 720 or 1.44 when the hole is covered?


  On Mon, Mar 25, 2019, at 7:37 AM, Stephen Adolph wrote:

Kurt, agree with everything you have said.



The odd thing is-



* using an HD disk in an DD/HD drive, and covering the hole with tape, 
would seem to be BAD

---> because you are telling the drive to use the wrong current settings 
for the actual disk media.



However, this is apparently the way to make my system functional.



so, strange.  I would have thought it would be the opposite - let the drive 
decide what current to use, matched to the "cookie".





On Mon, Mar 25, 2019 at 10:19 AM Kurt McCullum  wrote:



  The magnetic coercivity on HD disks is different than on regular disks. 
It requires more energy to lay down the tracks. If you start with a blank HD 
disk rather than a pre-formatted disk then you have a better chance. That's 
because once the HD tracks are laid down, you need to erase them for your new 
format. If your drive doesn't have enough energy to completely erase the 
existing track, it wont work. 720k disks have a lower coercivity and therefore 
work with either a 720k or 1.44mb drive. A 1.44 drive has a sensor for the open 
hole and when it sees that hole, it will use a higher level of write energy to 
properly work with the media. When that hole is covered, it will use a lower 
level which is what the 720k media is looking for. Though I do remember that 
formatting a 720k disk in a 1.44mb drive didn't always work when going back to 
a 720k drive. 



  Not sure about the Coco drive, but my TPDD2 does not work reliably with 
HD disks. I have only been able to format one properly and it had data failure 
shortly after.



  Kurt



  On Sun, Mar 24, 2019, at 6:32 PM, Stephen Adolph wrote:

interestingly,



Yes, if I take an HD disk, and tape over the hole to make it appear to 
be a DD disk, then it works.



But why?



the floppy is capable of both formats...



On Sun, Mar 24, 2019 at 7:39 PM Mike Stein  wrote:



  Have you tried closing the HD sense hole with a piece of tape or 
similar?

- Original Message -

From: Stephen Adolph

To: m...@bitchin100.com

Sent: Sunday, March 24, 2019 6:08 PM

Subject: Re: [M100] question regarding floppy disks.



the Coco is using it's standard controller



When issuing the DSKINI 0 command the coco tries to format for 
180kB.



The combination of 

(Coco, std controller, PC 1.44MB drive + a 720kB dd floppy) works



whereas

(Coco, std controller, PC 1.44MB drive + a 1.44MBB hd floppy) does 
not work



this is something I don't understand!







On Sun, Mar 24, 2019 at 5:42 PM Gregory McGill 
 wrote:

  likely the floppy controller doesn't support 80 tracks or high 
density..  most of the controllers of the era are ds/sd 40 track or dsdd 40 
track..   

Re: [M100] question regarding floppy disks.

[Stephen Adolph]

when attached to a CoCo, you get 160k.

On Mon, Mar 25, 2019 at 11:02 AM Kurt McCullum  wrote:

> Yeah that does sound strange. And I agree, the drive 'should' switch based
> on the hole in the disk. Does it format to 720 or 1.44 when the hole is
> covered?
>
> On Mon, Mar 25, 2019, at 7:37 AM, Stephen Adolph wrote:
>
> Kurt, agree with everything you have said.
>
> The odd thing is-
>
> * using an HD disk in an DD/HD drive, and covering the hole with tape,
> would seem to be BAD
> ---> because you are telling the drive to use the wrong current settings
> for the actual disk media.
>
> However, this is apparently the way to make my system functional.
>
> so, strange.  I would have thought it would be the opposite - let the
> drive decide what current to use, matched to the "cookie".
>
>
> On Mon, Mar 25, 2019 at 10:19 AM Kurt McCullum  wrote:
>
>
> The magnetic coercivity on HD disks is different than on regular disks. It
> requires more energy to lay down the tracks. If you start with a blank HD
> disk rather than a pre-formatted disk then you have a better chance. That's
> because once the HD tracks are laid down, you need to erase them for your
> new format. If your drive doesn't have enough energy to completely erase
> the existing track, it wont work. 720k disks have a lower coercivity and
> therefore work with either a 720k or 1.44mb drive. A 1.44 drive has a
> sensor for the open hole and when it sees that hole, it will use a higher
> level of write energy to properly work with the media. When that hole is
> covered, it will use a lower level which is what the 720k media is looking
> for. Though I do remember that formatting a 720k disk in a 1.44mb drive
> didn't always work when going back to a 720k drive.
>
> Not sure about the Coco drive, but my TPDD2 does not work reliably with HD
> disks. I have only been able to format one properly and it had data failure
> shortly after.
>
> Kurt
>
> On Sun, Mar 24, 2019, at 6:32 PM, Stephen Adolph wrote:
>
> interestingly,
>
> Yes, if I take an HD disk, and tape over the hole to make it appear to be
> a DD disk, then it works.
>
> But why?
>
> the floppy is capable of both formats...
>
> On Sun, Mar 24, 2019 at 7:39 PM Mike Stein  wrote:
>
>
> Have you tried closing the HD sense hole with a piece of tape or similar?
>
> - Original Message -
> *From:* Stephen Adolph 
> *To:* m...@bitchin100.com
> *Sent:* Sunday, March 24, 2019 6:08 PM
> *Subject:* Re: [M100] question regarding floppy disks.
>
> the Coco is using it's standard controller
>
> When issuing the DSKINI 0 command the coco tries to format for 180kB.
>
> The combination of
> (Coco, std controller, PC 1.44MB drive + a 720kB dd floppy) works
>
> whereas
> (Coco, std controller, PC 1.44MB drive + a 1.44MBB hd floppy) does not work
>
> this is something I don't understand!
>
>
>
> On Sun, Mar 24, 2019 at 5:42 PM Gregory McGill 
> wrote:
>
> likely the floppy controller doesn't support 80 tracks or high density..
> most of the controllers of the era are ds/sd 40 track or dsdd 40 track..
>  are you able to format 720k? ds/dd 80 track?
>
> Greg
>
> On Sun, Mar 24, 2019 at 2:38 PM Stephen Adolph 
> wrote:
>
> I'll start by saying this isn't an M100 or TPDD discussion, but just
> looking to understand something.
>
> I have a Tandy Coco3 with a 3.5 inch floppy drive.  The drive is a
> standard PC drive and it is working well.
>
> Seems though that I cannot use 1.44 MB floppies in that drive. They don't
> seem to want to format.
>
> I really don't understand where the problem could be.
> - the drive and the floppy are compatible
> - the disk is known good and formats at 1.44MB in a PC
> - if it can support 135 TPI, why can't it support 35 TPI?
>
> Does anyone know what's going on?
>
> thx
> Steve
>
>
>
>

Re: [M100] question regarding floppy disks.

[Kurt McCullum]

Yeah that does sound strange. And I agree, the drive 'should' switch based on 
the hole in the disk. Does it format to 720 or 1.44 when the hole is covered?

On Mon, Mar 25, 2019, at 7:37 AM, Stephen Adolph wrote:
> Kurt, agree with everything you have said.
> 
> The odd thing is-
> 
> * using an HD disk in an DD/HD drive, and covering the hole with tape, would 
> seem to be BAD
> ---> because you are telling the drive to use the wrong current settings for 
> the actual disk media.
> 
> However, this is apparently the way to make my system functional.
> 
> so, strange. I would have thought it would be the opposite - let the drive 
> decide what current to use, matched to the "cookie".
> 
> 
> On Mon, Mar 25, 2019 at 10:19 AM Kurt McCullum  wrote:
>> __
>> The magnetic coercivity on HD disks is different than on regular disks. It 
>> requires more energy to lay down the tracks. If you start with a blank HD 
>> disk rather than a pre-formatted disk then you have a better chance. That's 
>> because once the HD tracks are laid down, you need to erase them for your 
>> new format. If your drive doesn't have enough energy to completely erase the 
>> existing track, it wont work. 720k disks have a lower coercivity and 
>> therefore work with either a 720k or 1.44mb drive. A 1.44 drive has a sensor 
>> for the open hole and when it sees that hole, it will use a higher level of 
>> write energy to properly work with the media. When that hole is covered, it 
>> will use a lower level which is what the 720k media is looking for. Though I 
>> do remember that formatting a 720k disk in a 1.44mb drive didn't always work 
>> when going back to a 720k drive. 
>> 
>> Not sure about the Coco drive, but my TPDD2 does not work reliably with HD 
>> disks. I have only been able to format one properly and it had data failure 
>> shortly after.
>> 
>> Kurt
>> 
>> On Sun, Mar 24, 2019, at 6:32 PM, Stephen Adolph wrote:
>>> interestingly,
>>> 
>>> Yes, if I take an HD disk, and tape over the hole to make it appear to be a 
>>> DD disk, then it works.
>>> 
>>> But why?
>>> 
>>> the floppy is capable of both formats...
>>> 
>>> On Sun, Mar 24, 2019 at 7:39 PM Mike Stein  wrote:
 __
 Have you tried closing the HD sense hole with a piece of tape or similar?
> - Original Message -
> *From:* Stephen Adolph 
> *To:* m...@bitchin100.com
> *Sent:* Sunday, March 24, 2019 6:08 PM
> *Subject:* Re: [M100] question regarding floppy disks.
> 
> the Coco is using it's standard controller
> 
> When issuing the DSKINI 0 command the coco tries to format for 180kB.
> 
> The combination of 
> (Coco, std controller, PC 1.44MB drive + a 720kB dd floppy) works
> 
> whereas
> (Coco, std controller, PC 1.44MB drive + a 1.44MBB hd floppy) does not 
> work
> 
> this is something I don't understand!
> 
> 
> 
> On Sun, Mar 24, 2019 at 5:42 PM Gregory McGill  
> wrote:
>> likely the floppy controller doesn't support 80 tracks or high density.. 
>> most of the controllers of the era are ds/sd 40 track or dsdd 40 track.. 
>> are you able to format 720k? ds/dd 80 track? 
>> 
>> Greg
>> 
>> On Sun, Mar 24, 2019 at 2:38 PM Stephen Adolph  
>> wrote:
>>> I'll start by saying this isn't an M100 or TPDD discussion, but just 
>>> looking to understand something.
>>> 
>>> I have a Tandy Coco3 with a 3.5 inch floppy drive. The drive is a 
>>> standard PC drive and it is working well.
>>> 
>>> Seems though that I cannot use 1.44 MB floppies in that drive. They 
>>> don't seem to want to format.
>>> 
>>> I really don't understand where the problem could be.
>>> - the drive and the floppy are compatible
>>> - the disk is known good and formats at 1.44MB in a PC
>>> - if it can support 135 TPI, why can't it support 35 TPI?
>>> 
>>> Does anyone know what's going on?
>>> 
>>> thx
>>> Steve
>> 

Re: [M100] question regarding floppy disks.

[Kurt McCullum]

The magnetic coercivity on HD disks is different than on regular disks. It 
requires more energy to lay down the tracks. If you start with a blank HD disk 
rather than a pre-formatted disk then you have a better chance. That's because 
once the HD tracks are laid down, you need to erase them for your new format. 
If your drive doesn't have enough energy to completely erase the existing 
track, it wont work. 720k disks have a lower coercivity and therefore work with 
either a 720k or 1.44mb drive. A 1.44 drive has a sensor for the open hole and 
when it sees that hole, it will use a higher level of write energy to properly 
work with the media. When that hole is covered, it will use a lower level which 
is what the 720k media is looking for. Though I do remember that formatting a 
720k disk in a 1.44mb drive didn't always work when going back to a 720k drive. 

Not sure about the Coco drive, but my TPDD2 does not work reliably with HD 
disks. I have only been able to format one properly and it had data failure 
shortly after.

Kurt

On Sun, Mar 24, 2019, at 6:32 PM, Stephen Adolph wrote:
> interestingly,
> 
> Yes, if I take an HD disk, and tape over the hole to make it appear to be a 
> DD disk, then it works.
> 
> But why?
> 
> the floppy is capable of both formats...
> 
> On Sun, Mar 24, 2019 at 7:39 PM Mike Stein  wrote:
>> __
>> Have you tried closing the HD sense hole with a piece of tape or similar?
>>> - Original Message -
>>> *From:* Stephen Adolph 
>>> *To:* m...@bitchin100.com
>>> *Sent:* Sunday, March 24, 2019 6:08 PM
>>> *Subject:* Re: [M100] question regarding floppy disks.
>>> 
>>> the Coco is using it's standard controller
>>> 
>>> When issuing the DSKINI 0 command the coco tries to format for 180kB.
>>> 
>>> The combination of 
>>> (Coco, std controller, PC 1.44MB drive + a 720kB dd floppy) works
>>> 
>>> whereas
>>> (Coco, std controller, PC 1.44MB drive + a 1.44MBB hd floppy) does not work
>>> 
>>> this is something I don't understand!
>>> 
>>> 
>>> 
>>> On Sun, Mar 24, 2019 at 5:42 PM Gregory McGill  
>>> wrote:
 likely the floppy controller doesn't support 80 tracks or high density.. 
 most of the controllers of the era are ds/sd 40 track or dsdd 40 track.. 
 are you able to format 720k? ds/dd 80 track? 
 
 Greg
 
 On Sun, Mar 24, 2019 at 2:38 PM Stephen Adolph  
 wrote:
> I'll start by saying this isn't an M100 or TPDD discussion, but just 
> looking to understand something.
> 
> I have a Tandy Coco3 with a 3.5 inch floppy drive. The drive is a 
> standard PC drive and it is working well.
> 
> Seems though that I cannot use 1.44 MB floppies in that drive. They don't 
> seem to want to format.
> 
> I really don't understand where the problem could be.
> - the drive and the floppy are compatible
> - the disk is known good and formats at 1.44MB in a PC
> - if it can support 135 TPI, why can't it support 35 TPI?
> 
> Does anyone know what's going on?
> 
> thx
> Steve

Re: [M100] question regarding floppy disks.

[Stephen Adolph]

Kurt, agree with everything you have said.

The odd thing is-

* using an HD disk in an DD/HD drive, and covering the hole with tape,
would seem to be BAD
---> because you are telling the drive to use the wrong current settings
for the actual disk media.

However, this is apparently the way to make my system functional.

so, strange.  I would have thought it would be the opposite - let the drive
decide what current to use, matched to the "cookie".


On Mon, Mar 25, 2019 at 10:19 AM Kurt McCullum  wrote:

> The magnetic coercivity on HD disks is different than on regular disks. It
> requires more energy to lay down the tracks. If you start with a blank HD
> disk rather than a pre-formatted disk then you have a better chance. That's
> because once the HD tracks are laid down, you need to erase them for your
> new format. If your drive doesn't have enough energy to completely erase
> the existing track, it wont work. 720k disks have a lower coercivity and
> therefore work with either a 720k or 1.44mb drive. A 1.44 drive has a
> sensor for the open hole and when it sees that hole, it will use a higher
> level of write energy to properly work with the media. When that hole is
> covered, it will use a lower level which is what the 720k media is looking
> for. Though I do remember that formatting a 720k disk in a 1.44mb drive
> didn't always work when going back to a 720k drive.
>
> Not sure about the Coco drive, but my TPDD2 does not work reliably with HD
> disks. I have only been able to format one properly and it had data failure
> shortly after.
>
> Kurt
>
> On Sun, Mar 24, 2019, at 6:32 PM, Stephen Adolph wrote:
>
> interestingly,
>
> Yes, if I take an HD disk, and tape over the hole to make it appear to be
> a DD disk, then it works.
>
> But why?
>
> the floppy is capable of both formats...
>
> On Sun, Mar 24, 2019 at 7:39 PM Mike Stein  wrote:
>
>
> Have you tried closing the HD sense hole with a piece of tape or similar?
>
> - Original Message -
> *From:* Stephen Adolph 
> *To:* m...@bitchin100.com
> *Sent:* Sunday, March 24, 2019 6:08 PM
> *Subject:* Re: [M100] question regarding floppy disks.
>
> the Coco is using it's standard controller
>
> When issuing the DSKINI 0 command the coco tries to format for 180kB.
>
> The combination of
> (Coco, std controller, PC 1.44MB drive + a 720kB dd floppy) works
>
> whereas
> (Coco, std controller, PC 1.44MB drive + a 1.44MBB hd floppy) does not work
>
> this is something I don't understand!
>
>
>
> On Sun, Mar 24, 2019 at 5:42 PM Gregory McGill 
> wrote:
>
> likely the floppy controller doesn't support 80 tracks or high density..
> most of the controllers of the era are ds/sd 40 track or dsdd 40 track..
>  are you able to format 720k? ds/dd 80 track?
>
> Greg
>
> On Sun, Mar 24, 2019 at 2:38 PM Stephen Adolph 
> wrote:
>
> I'll start by saying this isn't an M100 or TPDD discussion, but just
> looking to understand something.
>
> I have a Tandy Coco3 with a 3.5 inch floppy drive.  The drive is a
> standard PC drive and it is working well.
>
> Seems though that I cannot use 1.44 MB floppies in that drive. They don't
> seem to want to format.
>
> I really don't understand where the problem could be.
> - the drive and the floppy are compatible
> - the disk is known good and formats at 1.44MB in a PC
> - if it can support 135 TPI, why can't it support 35 TPI?
>
> Does anyone know what's going on?
>
> thx
> Steve
>
>
>

Re: [M100] REX: Downloading OPTROM images

[Stephen Adolph]

what dual rom 128k ram memory system?  very interesting!  I'm interested to
learn more. might be a conflict however with REX, depending on the
details...

On Sun, Mar 24, 2019 at 10:39 PM Peter Noeth  wrote:

> Group,
>
>   I purchased a REX at Tandy Assembly 2018, but am just now getting around
> to testing it with my T102 Dual ROM/128KB RAM Memory System.
>
>   The REX Wiki instructions tell of needing a TPDD PC emulator (I have no
> TPDD device) but it does not indicate what program to use, or where to
> download it. I believe that either LaddieCon or LaddieAlpha is what I need.
> But after searching for them, I found a download link on the LaddieCon Wiki
> (on http://bitchin100.com/wiki/index.php?title=LaddieCon) that when the
> programs download, the Win7 Smart Screen Filter reports them as unsafe.
>
>   Is this the correct place to download the files? If so, are they really
> unsafe?
>
> Regards,
>
> Peter
>