Re: Converting .DSK images to 5.25" floppy (part 2)

["Charlie" <charlied@NOSPAMbboard.com>]

"Michael J. Mahon" <mjmahon@aol.com> wrote in message
20031104195811.28612.00000173@mb-m05.aol.com">news:20031104195811.28612.00000173@mb-m05.aol.com...
> Charlie wrote:

> >If you just want to _read_ Apple II disks, you might want to try Disk2FDI (a
> >shareware program by Vincent Joguin).  It allows you to read Apple II 5.25"
> >disks on a PC with no unusual hardware.
>
> Yes, I almost made a reference to his post, but was waiting for some
> confirmatory experience...which you have provided.  ;-)
> >I have been "playing around" with this program for a couple days and I have
> >say
> >that it does what I thought was impossible.  It reads a disk and saves it to
> >a
> >disk image in about one minute (longer if the original disk has bad
sectors).
> >
> >You do have to re-arrange the sectors on the image to make them usable in an
> >emulator but every byte of data is there.  In case you want to try it I
found
> >the following to work.
> >
> >
> >Disk2fdi  should be
> >sector #
> >--------  ---------
> >       0  0
> >       D  1
> >       B  2
> >       9  3
> >       7  4
> >       5  5
> >       3  6
> >       1  7
> >       E  8
> >       C  9
> >       A  A
> >       8  B
> >       6  C
> >       4  D
> >       2  E
> >       F  F
>
> This is the DOS 3.3 skew table (logical to physical sector mapping).

The author has updated the program (version 0.96 alpha) and it now correctly
creates a DOS ordered (.DO) file.

> >A couple other things to note:
> >
> >You have to have two floppy disk drives on your PC (only one has to be a
> >5.25").
> >It won't work on Windows XP/2000/NT.
> >I don't think it will work on the flip side of Apple II disks.
> >You can't write to the Apple II disks with the PC.
> >
> >It is supposed to work for other non-PC disks as well but I haven't tried
it.
> >
> >Here's a link:
> >
> >http://www.oldskool.org/disk2fdi
>
> His technique of starting a disk read on a PC-formatted disk,
> waiting for it to sync up and start to transfer data, and then
> switching on the fly to the drive containing the non-PC disk
> is quite novel.

I agree.

> Does it work with the Apple disk in a high-density 5.25" drive
> and the PC disk drive a 3.5"?  (This is a fairly common drive
> configuration on older machines.)

Yes, this is the configuration I am using (I had to install 5.25" drive. I
never had a use for it before).  By the way, you need to have a formatted
floppy in the other drive.  It is not written to.

> Does his program convert the nibbles to normal sectors,
> or is that exercise left to the user?  (I found his documentation
> rather cryptic to a non-Amiga person.)

Yes, it converts the nibbles to normal disk image sectors.  It is a very easy
to use DOS program (it will run in a Windows 9x/ME console window also).  Now
with the update, on my machine it produces a perfect .DO file that can be run
in an emulator without any changes needed. I use a simple .bat file that allows
me to just put the Apple disk in the drive and click on the .bat file image.
Disk2FDI does the rest.

> If the PC disk controller is configured to read only from the
> "bottom" surface, then flipping the disk over should work fine
> (since the technique already finesses the index hole).

I questioned Vincent on this.  He said that some older 360K drives will allow
flipping the disk.  He said that just reading from the other head reads the
data backwards but the main problem is that the other head is positioned
differently so you loose three tracks.  Apparently "flipped" disks is a problem
with the Catweasel card because he referred me to a site that shows a hardware
fix so a drive can read a flipped disk.
I found the information on the site to be cryptic but here it is if you are
interested:

http://home.t-online.de/home/indcomp/flipside.html


> Many no doubt consider writing Apple II disks on a PC (which
> apparently is impossible) the holy grail, but being able to read
> them, however slowly, is quite handy.

I have found it to be pretty fast considering what it is doing.  A normal DOS
3.3 or ProDOS disk that is in good shape (no bad sectors) usually takes 50 to
70 seconds from the time Disk2FDI starts until I have a disk image on my hard
drive ready to run in an emulator.
This has prompted me to start archiving my old disks.  I did about 30 disks
this afternoon with no problems and these disks were 20+ years old.  Disks that
were copy-protected usually wouldn't copy but that was expected.
Disk2FDI is supposed to work with 13 sector DOS 3.2 and 3.1 but I haven't
tested that yet.
I'm not sure if any emulators will handle 13 sector images either.

Charlie