User`s guide

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From: Rubywand, Orgone Accumulator, Greg E. Nelson, Eric Shepherd, Roger
Johnstone
006- What are DSK, PO, DO, HDV, NIB, and 2MG "disk image"
files and how do I use them?
A "disk image" is typically a file containing every data byte on a
diskette-- i.e. Catalog tracks, files, DOS (if present) etc.. One kind of disk
image, NIB, tries to preserve all disk information (e.g. sector headers, sync
bytes, etc.).
Apple II emulators running on a PC, Mac, etc. treat disk image files like
diskettes. Disk image files are also a handy way to archive Apple II disks on
hard disk and to maintain wares on ftp and other download sites.
DSK's (.dsk, .do, .po and .hdv files)
DSK (usually .dsk) files are disk image files used by popular Apple II
emulators like AppleWin to run A2 wares on the PC or Mac. Usually, they are
images of Apple 5.25" game, utility, etc. diskettes. A standard 5.25" DSK file
is 143,360 bytes in length:
1 side x 35 Tracks/side x 16 Sectors/Trk x 256 Bytes/Sec = 143,360 Bytes.
DSK files of 800k 3.5" disks are much less common.
Data in a DSK disk image file can be arranged in the sector order used by
DOS 3.3 or in the sector order used by ProDOS. The filename suffixes relate
chiefly to how data is arranged in the file:
.dsk- technically, this may be an image which has its data in DOS 3.3 or ProDOS
order. (The emulator program is supposed to check a .dsk file to determine the
ordering used.) It has become standard practice to use the .dsk suffix for only
DOS 3.3 order files.
.do- an image which is in DOS 3.3 order. This suffix is seldom used today. DOS
3.3 order image file names usually end with ".dsk".
.po- an image which is in ProDOS order. If an image is in ProDOS order, its name
should end with ".po" (not ".dsk") to avoid confusion.
.hdv- typically an image 800k (819,200 bytes) or greater in size in ProDOS
order. The image is intended for use as a virtual hard disk by various Apple II
and IIgs emulators (e.g. Apple Oasis). The IIgs program ASIMOV2 can create .hdv
files (select "Raw image"). The file name should end with ".hdv".
Note: data order does not relate to whether a disk image is a DOS 3.3 or ProDOS
disk. In fact, nearly all 5.25" disk image files (of both DOS 3.3 and ProDOS
disks) are in DOS 3.3 order; and, DOS 3.3 order is the default setting for image
creation programs like DSK2FILE and ASIMOV and the transfer/creation program
ADT.