Difference between revisions of "YaPaDOS"

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YaPaDOS is patch for [[AMSDOS]] and [[ParaDOS]] that allows to redirect disk access to harddisk. This is done to keep highest possible compatibility, so only 20 bytes of RAM are used (including 6 used by PARADOS).
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YaPaDOS is patch for [[AMSDOS]] and [[ParaDOS]] that allows to redirect disk access to harddisk. This is done with keeping highest possible compatibility, so only 20 bytes of RAM are used (including 6 used by PARADOS).
  
Using only 20 bytes of RAM makes impossible features like FAT32 and support for .DSK files, so the disk has special formatting using IDEDOS structures (by Garry Lancaster).
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Instead of reading and writting floppy, a continous and limited area on harddisk is used, that has the same amount of sectors, as the floppy. The area is called diskimage. Each drive separately A: and B: can be directed to floppy or one of diskimages. You can change the diskimages as you would change the floppies, but by opening some special files.
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Using only 20 bytes of RAM makes impossible features like FAT32 and support for .DSK files, so the disk must have special formatting using IDEDOS structures (by Garry Lancaster). The harddisk can also contain FAT partitions, but they are not accessible from YaPaDOS.
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The IDEDOS partition contain diskimages, that can have various size (e.g. 180kB, 800kB, 5MB). Up to 999 diskimages can be created and accessed.
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Diskimages are selected by their numbers 1..999 (0 means floppy). Only the number after dot matters. Names of diskimages can be listed from a virtual device called superdisk. Superdisk is read-only. After the superdisk is selected, the diskimage then can be selected without the ^ sign in file name.
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The ^ sign placed as first in file name used in open file function tells the operating system to do something special:
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LOAD"^" - selects superdisk
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LOAD"^xxxxxxx.nnn" - selects diskimage number nnn
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LOAD"^.0" - selects floppy
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LOAD"^DESTROY.MBR" - clears MS-DOS partition table
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LOAD"^DBnnnnn.mmm" - creates IDEDOS partition of nnnnn cylinders and up to mmm diskimages
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LOAD"^MAKENEW" - adds diskimage respectively to current XDPB
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LOAD"^MAKENEW.nnn" - as above, but enlarage to nnn kilobytes for safety
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The ^ sign allows to change diskimages in every old software that enables opening any file and not crashes, when the file is empty. No changes in such software are needed to select diskimage on harddisk or redirect the drive to floppy.

Revision as of 07:28, 25 October 2007

YaPaDOS is patch for AMSDOS and ParaDOS that allows to redirect disk access to harddisk. This is done with keeping highest possible compatibility, so only 20 bytes of RAM are used (including 6 used by PARADOS).

Instead of reading and writting floppy, a continous and limited area on harddisk is used, that has the same amount of sectors, as the floppy. The area is called diskimage. Each drive separately A: and B: can be directed to floppy or one of diskimages. You can change the diskimages as you would change the floppies, but by opening some special files.

Using only 20 bytes of RAM makes impossible features like FAT32 and support for .DSK files, so the disk must have special formatting using IDEDOS structures (by Garry Lancaster). The harddisk can also contain FAT partitions, but they are not accessible from YaPaDOS.

The IDEDOS partition contain diskimages, that can have various size (e.g. 180kB, 800kB, 5MB). Up to 999 diskimages can be created and accessed.

Diskimages are selected by their numbers 1..999 (0 means floppy). Only the number after dot matters. Names of diskimages can be listed from a virtual device called superdisk. Superdisk is read-only. After the superdisk is selected, the diskimage then can be selected without the ^ sign in file name.

The ^ sign placed as first in file name used in open file function tells the operating system to do something special:

LOAD"^" - selects superdisk LOAD"^xxxxxxx.nnn" - selects diskimage number nnn LOAD"^.0" - selects floppy

LOAD"^DESTROY.MBR" - clears MS-DOS partition table LOAD"^DBnnnnn.mmm" - creates IDEDOS partition of nnnnn cylinders and up to mmm diskimages LOAD"^MAKENEW" - adds diskimage respectively to current XDPB LOAD"^MAKENEW.nnn" - as above, but enlarage to nnn kilobytes for safety


The ^ sign allows to change diskimages in every old software that enables opening any file and not crashes, when the file is empty. No changes in such software are needed to select diskimage on harddisk or redirect the drive to floppy.