Subject: Re: [TI994A] Re: Floppy Issues - Single Density

From: "Paolo Bagnaresi" <[email-masked]>
Date: Mon, 5 Jul 2010 09:11:00 +0200

Chris,

if I'm not wrong, you just tried to read Single Density disks. What about 
writing and formatting them? If and when you have time, could you do some 
tests, so that we can safely list motherboards with the ITE IT8720 chip as 
fully compatible with Single Density?

Thanks,

Paolo

----- Original Message ----- 
From: "Paolo Bagnaresi" <[email-masked]>
To: <[email-masked]>
Sent: Monday, July 05, 2010 12:41 AM
Subject: Re: [TI994A] Re: Floppy Issues

> Thank you Chris.
>
> There are a bunch of Gigabyte motherboards that use the ITE IT8720 chip 
> for FDD:
> GA-870A-UD3, GA-P55A-UD4, GA-P55-UD6, GA-EX58-UD3R, GA-MA770T-UD3P, 
> GA-M720-US3, GA-EP45 DS4R
>
> Somebody might be interested. ;-)
>
> Paolo
>
>
> ----- Original Message ----- 
> From: "chris20636" To: <[email-masked]>
> Sent: Saturday, July 03, 2010 6:58 PM
> Subject: [TI994A] Re: Floppy Issues
>
>
> For the record, my motherboard floppy controller seems to be implemented 
> by an ITE IT8720 chip.  This also does the hardware monitoring and other 
> miscellaneous I/O functions.
>
> Posted in case any of the big brained guys are keeping records.
>
> Regards,
> Chris
>
> --- In [email-masked], "chris20636" <chrisas@...> wrote:
>>
>> I have a PC with BIOS support for 360K and 1.2M 5.25" floppy devices. 
>> I
>> have a Teac FD55GFR 7149-U5 1.2MB 5.25 Floppy Disk Drive DSHD installed
>> with the BIOS set to 1.2M 5.25".  Unfortunately I have 64 bit Windows 7
>> Home.  So that leaves me without access to either TI99-PC or Omniflop.
>> However, I also have linux installed.
>>
>> I can take a Texas Instruments floppy and dump each track like this on
>> linux:
>>
>> fdrawcmd rate=1 track=2*LTRACK fm length=2304 read 0 LTRACK 0
>> STARTSECTOR 1 9 0x1b 0xff need_seek > track
>>
>> LTRACK is a variable for the logical track holder.  Since this is a
>> single density disk, each Logical track seems to cover 2 physical 
>> tracks
>> which is why the "track=" parameter is twice the LTRACK number.  LTRACK
>> gets replaced with one of 0,1,2,3...,39 while track= goes as
>> 0,2,4,6,...78.
>>
>> STARTSECTOR is the starting sector.  In the case of the TI disks, this
>> is "0".
>>
>> So to read the first track, track 0, I would do this,
>> fdrawcmd rate=1 track=0 fm length=2304 read 0 0 0 0 1 9 0x1b 0xff
>> need_seek > track01
>> Track 2 would be
>> fdrawcmd rate=1 track=2 fm length=2304 read 0 1 0 0 1 9 0x1b 0xff
>> need_seek > track02
>> etc.
>>
>> I then concatenate the 39 tracks into a single disk image.  A hexdump
>> shows good structure and TI99Dir can read the contents.
>>
>> Now for the problem:  I did the above for three Texas instruments
>> floppies just fine.  However, I have some Asgard Software disks that I
>> want to image.  I do the same procedure and it fails.  This is because 
>> I
>> can read sectors 1-8 on each track, but I can't read sector 0 (or 9?).
>> So I'm only able to read 8 of the 9 sectors per track.  A hexdump
>> reveals that the missing ninth sector is needed to make a valid image.
>>
>> Any ideas?
>>
>> Thanks,
>> Chris
>>
>
>
>

---

From: "chris20636" <[email-masked]>
Date: Mon, 05 Jul 2010 21:51:33 -0000

Paolo,

That is correct, I have only attempted to read single density disks.  I only have one blank floppy that has already been formatted as 80 track.  I will be getting a supply of 5.25 DSDD's in the mail.  When those arrive I can do some format testing.  Meanwhile, I'm using the single disk I have to try and find the right fdutils commands to do a successful format.

Here are the single density test cases that I think you might be interested in.
1) Use unformatted disk and format just the even physical tracks for 40 tracks total.  Then do write/read tests.
2) Use unformatted disk and format using all 80 physical tracks but set the same logical cylinder/head/sector tor two consecutive tracks to make up 40 logical tracks spanning 80 physical tracks.  Do write/read tests
3) Take a disk formatted as 80 physical tracks and try to reformat just the even (40) tracks and see if "bleed through" from odd tracks interferes with write/read tests of the new 40 tracks.

On a related topic, I was able to run dosbox emulator for 64 bit Linux.  Your qbasic included with TI99-PC seemed to work.  I needed to force the detection of the operating system as MS-DOS version 5.0 in your code.  That made the menus work.  However, the COM file that does all the work didn't like working with the dosbox floppy that was mounted to my "/dev/fd0" in linux.  Well, it was worth a try.

Chris

--- In [email-masked], "Paolo Bagnaresi" <paul.bagnaresi@...> wrote:
> From: "Paolo Bagnaresi" <paul.bagnaresi@...>
> > --- In [email-masked], "chris20636" <chrisas@> wrote:
> >>

---

From: "Paolo Bagnaresi" <[email-masked]>
Date: Wed, 7 Jul 2010 02:04:25 +0200

Chris,

I have already sent you a TI Single Density Test (Test-pcx.zip, 635 KB).
Basically, you first create a Windows-ME 3.5" boot floppy disk with it and 
then
you boot from it. Next you run the code inside the floppy, and this will
try to format a 3.5" floppy disk as TI Single Density.

If no error after Formatting/copying is issued, then you can be sure your
PC is fully capable of Reading, Writing and Formatting a TI Single Density
Disk.

P.S.
When formatting an 1.44 MB disk as TI Single Density, and the floppy is
already formatted as 1.44 MB (thus, as High Density), sometimes the 
formatting as Single Density will not work well the first two times . 
Before ruling out the test as a failure, please try the same test at least 
3 times.

As to your message.

Regarding your planned tests, I am particularly interested in your test 
#2. Always thought of that, but never actually tried it myself. I suspect 
the test will fail, either because of the "no man land" between the same 
two logical tracks (this might confuse the drive head), or because the two 
writings will take place in two different times and nothing guarantees 
that the two data flows are exactly in sync, bit after bit.

At any rate, the following is what I know:

a) There is no difference whatsoever between using a 5.25" or a 3.5" 
drive. Whatever works on one will work on the other too. Ditto for 
whatever doesn't work. Of course the capacity does change, but what I'm 
referring to is the ability of handling Single Density.

b) 80 track disk drive will work very well on a disk formatted and written 
on a 40 track drive, as far as reading, writing and formatting is 
concerned. No "bleed through" because only the even track will be used. 
The only problem: don't use that disk on a 40 track drive any more, unless 
you have just read from it.

c) A 40 track disk written on a 80 track drive will not be read or written 
to properly when moved back to a 40 track drive. Of course, you can always 
reformat it on a 40 track drive as you like. That will take care of 
everything, except for your data.

c) Many times I wished I had a magnetic bulk eraser: some disks formatted 
in awkward formats cannot be formatted again as standard TI disks. 
Sometimes formatting them again as PC disks helps (any format will do). 
Then a TI format will work.

d) If your PC refuses to format a TI disk as DOS disk, or takes for ages 
before finally giving you the chance of formatting it, fool it this way: 
first insert a well formatted DOS disk and go on as if you were going to 
format that one one more time; next, slip in the previous disk, just 
before starting the new format. Your PC will hesitate a little, but it 
will comply after a while.

e) Sometimes TI99-PC.COM/TI99-PC.EXE get confused. When nothing works any 
more, not even floppies that used to work well, just exit TI99-PC and see 
if you can read a plain DOS floppy disk. If you can't (and that might 
indeed happen), shut down your pc and re-boot.
On the other had, if the DOS disk is read, simply re-enter TI99-PC.

Finaly, as to why TI99-PC.COM won't work on your dosbox emulator for 64 
bit Linux, I think it's because of the usual reason: hardware ports can 
not be directly accessed on emulators. But please tell me what actually 
happens on your machine. Usually, this is the scenario: the disk drive 
light goes on, you can hear the magnetic drive head stepping through the 
disk tracks while the formatting takes place, but when the verifying 
starts no good sector is detected. Is that what happens on your machine?

Paolo

----- Original Message ----- 
>Sent: Monday, July 05, 2010 11:51 PM
>Subject: [TI994A] Re: Floppy Issues - Single Density
>
>
>Paolo,
>
>That is correct, I have only attempted to read single density disks.  I 
>only have one blank floppy that has already been formatted as 80 track. 
>I will be getting a supply of 5.25 DSDD's in the mail.  When those arrive 
>I can do some format testing.  Meanwhile, I'm using the single disk I 
>have to try and find the right fdutils commands to do a successful 
>format.
>
>2) Use unformatted disk and format using all 80 physical tracks but set 
>the same logical cylinder/head/sector tor two consecutive tracks to make 
>up 40 logical tracks spanning 80 physical tracks.  Do write/read tests
>3) Take a disk formatted as 80 physical tracks and try to reformat just 
>the even (40) tracks and see if "bleed through" from odd tracks 
>interferes with write/read tests of the new 40 tracks.
>
>On a related topic, I was able to run dosbox emulator for 64 bit Linux. 
>Your qbasic included with TI99-PC seemed to work.  I needed to force the 
>detection of the operating system as MS-DOS version 5.0 in your code. 
>That made the menus work.  However, the COM file that does all the work 
>didn't like working with the dosbox floppy that was mounted to my 
>"/dev/fd0" in linux.  Well, it was worth a try.
>
>Chris
>
>
>

---

From: "chris20636" <[email-masked]>
Date: Tue, 13 Jul 2010 02:35:44 -0000

> PC is fully capable of Reading, Writing and Formatting a TI Single Density

Well I tried and tried and then tried some more.  However, the test disk doesn't give a successful result for single density formatting.  

> As to your message.

Thank you for the informative response.  It is stored away for future reference.

Regards,
Chris

---

From: "Dan" <[email-masked]>
Date: Tue, 13 Jul 2010 16:13:56 -0400

----- Original Message ----- 
From: "chris20636" <[email-masked]>
To: <[email-masked]>
Sent: Monday, July 12, 2010 10:35 PM
Subject: [TI994A] Re: Floppy Issues - Single Density
> Well I tried and tried and then tried some more.  However, the test disk
> doesn't give a successful result for single density formatting.
> > I have a Teac FD55GFR 7149-U5 1.2MB 5.25 Floppy Disk Drive DSHD

Chris
seems I may be the only one that remembers this but you CANT use a 1.2 meg 
drive in any TI related endeavors with any success.
some will say if you strap the speed to 300rpms you can use it as an 80track 
drive bit it still WONT work reliably for reading / writing existing 40 
track disk. So, if you are still using a 1.2meg toss it and save yourself 
some aggravation.

Good luck

Dan

btw
1.2meg floppy use has been beat to death over the last 10-15 years so I 
suspect some folks are having selective memory failure :)

---

From: "Paolo Bagnaresi" <[email-masked]>
Date: Tue, 13 Jul 2010 22:40:39 +0200

Nice try anyhow. I'll add this to a future update of TI99-PC manual, if 
there ever will be one again: it seems everybody has already got copies of 
their TI floppies as disk image files on a PC nowadays.

Thanks a lot!

Paolo

----- Original Message ----- 
From: "chris20636" <[email-masked]>
To: <[email-masked]>
Sent: Tuesday, July 13, 2010 4:35 AM
Subject: [TI994A] Re: Floppy Issues - Single Density

--- In [email-masked], "Paolo Bagnaresi" <paul.bagnaresi@...> 

> As to your message.

Thank you for the informative response.  It is stored away for future 
reference.

Regards,
Chris

---

From: "Paolo Bagnaresi" <[email-masked]>
Date: Tue, 13 Jul 2010 23:00:30 +0200

Dan,

you're certainly right if you *write* with a 1.2 MB drive to a floppy that 
will then be used on a 40 track drive on a TI.

However, if the disk has to be used on a 80 track drive on a TI, even a 
1.2 MB drive will write correctly to it.

The only thing you have to be concerned about is the 40/80 track issue.

The 300/360 rpm issue is never important: as a matter of fact a drive 
spinning at 360 rpm and writing at 300 Kb/s will lay down sectors 
physically identical to those layed down by a drive spinning at 300 rpm 
and writing at 250 Kb/s. When I say physically identical I mean that you 
will not be able to understand what drive has been used on that disk by a 
later inspection, that is, whether it was a 360 rpm or a 300 rpm drive. 
It's just a matter of a simple math: 360/300=300/250.

Paolo

---

From: "epergrem" <[email-masked]>
Date: Tue, 13 Jul 2010 21:02:29 -0000

Dan,
I have four of the FD55GR (2-149 U, 1-149 U5, 1-570 U) drives that I will be returning to Jon Guidry shortly.  

I recently used them with the Myarc 80-track EPROM, to transfer over 2,000 TI disks (SSSD, DSSD, DSDD) from my 99/4A to PC.

For my purposes they worked flawlessly.

Ernie

--- In [email-masked], "Dan" <dano@...> wrote:
> From: "chris20636" <chrisas@...>

---

From: "Paolo Bagnaresi" <[email-masked]>
Date: Tue, 13 Jul 2010 23:16:01 +0200

Dan,

as an additional note:

all my original TI disks were transferred to PC by reading them on a 1.2 
MB drive: I only had problems with disks that were unreadable on the TI 
too.

Paolo