Read/Write Floppy Three Times

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rain_storm

Joined: 05 Apr 2007
Posts: 67
Location: Ireland

rain_storm 31 Mar 2011, 21:13

Ralf Browns interrupt list states that you should read / write a sector to/from a floppy disc drive at least three times to ensure that the operation completed successfully. Is this absolutely necessary, I had no issues before I decided to go "by the book" on this. But now it's taking the best part of an hour to write a 1.4MB image. Where as before I could live with the 15 min time frame.

Edit:
read int 0x13 ah=0x02
write int 0x13 ah=0x03

31 Mar 2011, 21:13

Dex4u

Joined: 08 Feb 2005
Posts: 1601
Location: web

Dex4u 31 Mar 2011, 21:22

You do not need to read/write more than once unless you get a error.
Only on error do you try 3-4 times

Example

Code:

        mov   [FloppyTest],0
ReadWriteLoop:
        ;fill the right reg here
      int   13h
   jnc   ReadWriteOK
   inc   [FloppyTest]
  cmp   [FloppyTest],4
        jb    ReadWriteLoop

ReadWriteError:
       ;some code
ReadWriteOK:

Also if your using Dos, you can use int 21h functions for open, read, write, close, etc.

Last edited by Dex4u on 31 Mar 2011, 21:37; edited 2 times in total

31 Mar 2011, 21:22

rain_storm

Joined: 05 Apr 2007
Posts: 67
Location: Ireland

rain_storm 31 Mar 2011, 21:34

Thanks, should have spotted that one myself

Edit - MenuetOS still fails to boot, thought it was my program not writing properly but now it looks like its my hardware, DexOS boots just fine.

31 Mar 2011, 21:34

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