Convert DOS 3 Disk

[SteveB]

Hi,

 

I returned to my XL after quite some time ... I managed to rescue all my disks to disk images for emulator use. Like so many of us I bought a 1050 back in the days and used the included DOS 3 for some time. Is there a tool or a manual way to convert those images to a DOS 2.5 based format?

 

Perhaps I used wrong words but both Forum- and Google search delivered trillions of irrelevant entries...

 

Thank you

Steve

 

 

[TGB1718]

I can't remember any utility that can do the conversion, I know on the DOS 3 disk there's a utility to

copy DOS 2 files to DOS 3, but not the other way round, that why hardly anyone used it.

 

Maybe one of the 3rd party DOS's can read DOS 3 disks, someone here may be able to answer that.

[flashjazzcat]

According to this, there's a utility provided with DOS 2.5 which will do the conversion:

 

https://en.wikipedia.org/wiki/Atari_DOS

 

[TGB1718]

4 minutes ago, flashjazzcat said:

According to this, there's a utility provided with DOS 2.5 which will do the conversion:

Spot on, missed that, it's called copy32.com  on the DOS 2.5 disk

bitd, I only really used OS A+ or Spartados totally forgot about that.

Dos 2.5.atr

[+DjayBee]

I did not try it for Dos 3, but suppose that you can mount a Dos 3 ATR into Altirra, open Altirra's disk explorer and Drag&Drop all files to your Windows PC.

 

Now mount an empty Dos 2.5 ATR and go the other way which works for sure.

[TGB1718]

12 minutes ago, DjayBee said:

I did not try it for Dos 3, but suppose that you can mount a Dos 3 ATR into Altirra, open Altirra's disk explorer and Drag&Drop all files to your Windows PC.

 

Yes, that works to copy the disk to the PC.

 

I did try the utility 

https://rossumur.github.io/esp_8_bit/atr_image_explorer.htm

 

But it doesn't work for DOS 3 either

[SteveB]

37 minutes ago, TGB1718 said:

Spot on, missed that, it's called copy32.com  on the DOS 2.5 disk

bitd, I only really used OS A+ or Spartados totally forgot about that.

Dos 2.5.atr 130.02 kB · 0 downloads

I think this is the way for me to go! Thank you! I did not use the original DOS 2.5 much and never took notice of this COPY32.COM. 

 

I tried the Altirra "Convert Filesystem" but it gives me an error on DOS 3. 

 

[Rybags]

In emulator use it might be easier to just copy the files to H: though unsure if DOS 3 will allow it.  I got my 1050 in 1985 (I think) and it was a well known fact that 3 was a POC by then and 2.5 had been around for a while so I never used 3 beyond having a look at it.

[TGB1718]

1 hour ago, SteveB said:

I tried the Altirra "Convert Filesystem" but it gives me an error on DOS 3. 

Not sure what that is ??

 

Just use the Tools->Disk Explore

browse to your DOS 3 disk and open, you will see all the files on the floppy

drag and drop them into a folder on your PC.

Create a DOS2 disk image in Altirra and save it

use disk explore again to this new disk

drag and drop the files on your PC to this image.

 

[+DjayBee]

2 hours ago, SteveB said:

tried the Altirra "Convert Filesystem" but it gives me an error on DOS 3.

Schau mal da bzgl. Disk Explorer (H: überspringen):

https://abbuc.de/forum/viewtopic.php?p=6920#p6920

[flashjazzcat]

1 hour ago, TGB1718 said:

Not sure what that is ??

This is an option on the fly-out menu next to a disk slot in the 'Disk drives' dialog (presumably the user had mounted the ATR there instead of opening it with Disk Explorer).

[SteveB]

2 hours ago, DjayBee said:

Schau mal da bzgl. Disk Explorer (H: überspringen):

https://abbuc.de/forum/viewtopic.php?p=6920#p6920

Yes, it works also with DOS 3 with the H: Host Device. In both cases, it is a file-by-file conversion, something for long winter evenings... 

[sup8pdct]

Superdos5.1 has a built in util (part of aux.sys) that can copy from dos 3 to what ever density disk the destination is.

Superdos uses the same file system as dos 2 for single and double and dos2.5 for enhanced.

 

James

[Greg Miller]

I used the utility that came with DOS 2.5 to convert my files when I got it, although DOS 2.5 turned out to be a pretty big disappointment (mainly due to the really poor performance compared to DOS 3).

[BillC]

1 hour ago, Greg Miller said:

I used the utility that came with DOS 2.5 to convert my files when I got it, although DOS 2.5 turned out to be a pretty big disappointment (mainly due to the really poor performance compared to DOS 3).

The performance issue was why I switched to SpartaDOS once I moved on from DOS 3.0, high-speed SIO with Happy/USDoubler modified 1050s.

[Greg Miller]

Just now, BillC said:

The performance issue was why I switched to SpartaDOS once I moved on from DOS 3.0, high-speed SIO with Happy/USDoubler modified 1050s.

I eventually moved to SpartaDOS as well.

[+kheller2]

2 hours ago, Greg Miller said:

I used the utility that came with DOS 2.5 to convert my files when I got it, although DOS 2.5 turned out to be a pretty big disappointment (mainly due to the really poor performance compared to DOS 3).

Please elaborate said performance issue.  

[flashjazzcat]

I wouldn't be surprised if random file access and deleting large files were but two items on the list of things DOS 3 does faster/better than DOS 2.5 (since DOS 2.5 lacks relative seeks and must read every sector in a file in order to delete it).

Edited June 19, 2022 by flashjazzcat

[TGB1718]

11 hours ago, kheller2 said:

Please elaborate said performance issue.

DOS 3 organises the file system into 1K blocks, so reading a file can be achieved very quickly.

Starting from the first sector in a file, mostly it only needs to seek to another track once it's read a 1K

block of data (still only 128 bytes at a time) but unlikely to need a seek to another track.

So reading/writing should be quicker, as @flashjazzcat says DOS2.5 can have files spread all over the disk

so the head is seeking all the time for the next sector.

 

Where DOS 3 is a pain is the amount of wasted space on a disk, saving a 1 byte file take 1K, it ok

for larger files where you probably wouldn't notice much, but lots of small files and your disk is

full in no time, I think that's why it was so unpopular, I know that's the main reason I stopped using

it and it was so  incompatible with the dozens of disks I already had and of course friends who didn't

use DOS 3 made sharing files a real pain too.

[SteveB]

I now use MyPicoDos on a virtual DOS 2 Disk in Altirra as a program-launcher for cross-compiled FastBasic code. 

 

It's kind of religious, but what DOS should I use for other purposes in 2022 on Altirra and an unmodified 800XL with an SDrive-Max? And why ...? I was looking for some kind of "Norton Commander Interface", but neither Atari Commander 1.4 nor Tom's Navigator 1.22 could convince me so far as a shell.

 

I also liked DOS 3 and kept it for my own disks in my active time in the mid-eighties. By todays standards, I would not consider it ergonomic anymore.

 

[flashjazzcat]

1 hour ago, TGB1718 said:

DOS 3 organises the file system into 1K blocks, so reading a file can be achieved very quickly.

Starting from the first sector in a file, mostly it only needs to seek to another track once it's read a 1K

block of data (still only 128 bytes at a time) but unlikely to need a seek to another track.

So reading/writing should be quicker, as @flashjazzcat says DOS2.5 can have files spread all over the disk

so the head is seeking all the time for the next sector.

Having spent months writing FAT drivers from scratch, I've been sternly reminded that few older filesystems are without drawbacks (FAT lacking a linked list of free clusters or a bitmap allocation table, either of which would have fixed the most egregious problem with the design: cluster allocation), so the compromises in the Atari DOS 2.x and 3.0 file systems are a bit more forgivable in hindsight. While I fundamentally object to DOS 2.x keeping the sector links in data sectors, it does at least remove the need to constantly refer to linkage in a different location on disk when a file is simply being read from beginning to end. But trying to upscale this kind of linkage significantly (i.e., MYDOS) results in ponderously slow file deletion when disk capacity is greatly increased.

Edited June 19, 2022 by flashjazzcat

[+CharlieChaplin]

Turbo-DOS XL/XE comes with a DOS 3 + DOS 4 => DOS 2 converter program (DOS34CV.COM), there were also several freeware and PD programs (e.g. type-in listings) that did the job. Looks like I was always lucky and never had to convert anything from DOS 3 or DOS 4 to DOS 2.x format... so all these tools were never tested by me.

 

Some of these converter programs will only read/write from/to 90k disks and do not support 130k or higher.

 

 

DOS34_Conv.zip