Question on ATR file size: why so big?

[Theodore2]

Hi, 

Using my sio2SD to transfer files and disk images from my stock 1050 (running on a stock Atari800).  The ATR file starts off as a "blank" 131KB file on my SD card.  I then use the sio2SD to copy from the 1050 to the card.  When I put the SD card in my Windows computer, the ATR files are 8+MB each!?    But the files on them seem to work.  Am I doing something wrong?  Seems peculiar to me how a 90k atari floppy converts into a 8,192K atr file.

Please help.

Thanks

Theodore2  

Edited June 5, 2020 by Theodore2

[+Larry]

Removed.

[sup8pdct]

How are you creating the blank ATR's?

 

Sounds like 65535 sectors @ 128 bytes  = 8K. When only 720 are required.

 

James

 

 

[TGB1718]

SD Card is formatted as FAT, FAT creates blocks which I think defaults to 8K blocks

so saving any file less than 8K bytes the file still takes 8K on the disk.

[Frankie]

4 hours ago, sup8pdct said:

How are you creating the blank ATR's?

 

Sounds like 65535 sectors @ 128 bytes  = 8K.

 

That’s 8MB, not 8KB

 

[jamm]

4 hours ago, TGB1718 said:

SD Card is formatted as FAT, FAT creates blocks which I think defaults to 8K blocks

so saving any file less than 8K bytes the file still takes 8K on the disk.

I was going to say the same thing, but he's saying MB, not KB, and he says the file started off small at 131KB.  If he verified that the file was 131KB, then it can't be a formatting issue.  Something else is going on.  Could be as simple as misreading what's being shown.

[TGB1718]

5 minutes ago, jamm said:

Could be as simple as misreading what's being shown.

My thoughts too

[Theodore2]

Hi,

I'm trying not to cross-post, so here goes:

I got the BLANK .atr files from my thread here: https://atariage.com/forums/topic/306652-copying-files-from-1050-to-sio2sd/?tab=comments#comment-4534207 

and the specific attachment here: https://atariage.com/forums/applications/core/interface/file/attachment.php?id=730215

 

I used DOS2.5 to copy individual files from my original 1050 floppies to the blank 131kB .atr file on my sio2SD . 

 

I've yet to be able to have the atari read the .atr files I created from the sio2SD.  Maybe I'm doing something wrong for that.  Nevertheless, when I take the SD card and put into my modern windows laptop, the .atr files are now 8megabytes!  I can use Altirra atari emulator on my windows machine and read through the ATR and it looks ok.  I'm just confused why the file is so big.  I'm attaching an example of the 8MB file here.  In this case, the example is a public domain disk of TurboBasic that I copied.

All help and advice appreciated.

Thank you.

 

BRE_42_TurboBasic.atr

[sup8pdct]

10 hours ago, Frankie said:

That’s 8MB, not 8KB

 

my keyboard moved, the k appeared under my finger instead of the m.

 

my excuse and am sticking with it 

[+Roydea6]

8 hours ago, Theodore2 said:

I'm attaching an example of the 8MB file here. 

This file does have the proper header for an 8mB atr.  So something is going wrong.  I don't have the same SIO2SD device.  I need to wonder what DOS you are using to write the DOS file to the empty atr.  The 'H' option would set this density and it you are using the 'I' option then verify that you are using the 'p' and not the 'Y' responce.  For a 90k atr.

 

Edited June 6, 2020 by Roydea6
added DOS question.

[+Nezgar]

What sector copier is being used? Even though you're starting out with a 131K ATR, as soon as the sector copier issues a format command to the destination drive, all bets are off.

 

MyCopyR for instance has an option to turn off format destination.

[Theodore2]

In the example atr flle that I provided here, I used the "blank" atr that was given to me.  I then used Dos2.5 to copy *.* files onto the ATR.  I didn't use a sector copier for this example. And, somehow, I ended up with an 8MB file.  Do I need to make my own ATR from scratch? (I've no idea how to do that).  Do I need to "format" the atr in DOS2.5 before I copy stuff to it?  Would that help?