Disk images

86Box supports a large variety of disk image formats for the emulated disk drives.

Hard disk images

Supported formats:

Format File extension
Raw image Many *
Japanese FDI .hdi
Extended HDI (HDX) .hdx
Virtual Hard Disk .vhd

* Raw images come in many extensions, including .img and .ima

Hard disk size limits

There are limits to how big of a hard disk an emulated machine can accept. Such limits will vary depending on the machine’s age. Here are a few important ones:

Limit Disk size Cylinders Heads Sectors
20-bit CHS 504 MB 1024 16 63
Extended CHS 8032 MB 1024 256 63
65535 cylinders 32255 MB 65535 16 63
48-bit LBA 131071 MB Not applicable

These limits can be worked around (with caveats) by using software such as Ontrack Disk Manager, except for the 131071 MB one, which is a hard limit of 86Box’s hard disk emulation.

Floppy disk images

Supported formats:

Format File extension
Raw image Many *
86F .86f
CopyQM .cq / .cqm
DiskDupe .ddi
EZ-DisKlone Plus .fdf
Formatted Disk Image .fdi
HxC MFM .mfm
ImageDisk .imd
Japanese FDI .fdi
PCjs JSON .json
Teledisk .td0

* Raw images come in many extensions; the following ones are recognized by 86Box: .001 .002 .003 .004 .005 .006 .007 .008 .009 .010 .12 .144 .360 .720 .bin .dsk .flp .hdm .ima .img .vfd .xdf

Floppy disk detection

86Box determines the physical media format (sides, tracks per side, sectors per track, bytes per sector) of a floppy disk image through the following methods:

  1. Image file header data - not applicable for Raw and DiskDupe formats;
  2. DOS BIOS Parameter Block data within the image;
  3. If all else fails, a guess is made based on the image file’s size.

The BIOS Parameter Block detection method may behave incorrectly with non-DOS floppy disks. Installation floppies for UNIX and Linux are common examples of non-DOS disks. Disabling Check BPB is strongly recommended for accessing these, as an inaccurate BPB detection may result in read errors, data corruption and other issues.


When using a Raw image of a non-DOS floppy with Check BPB disabled, make sure the image file is not truncated (smaller than its media size), otherwise incorrect behavior may still occur.

MO / ZIP removable disk images

Supported formats:

Format File extension
Raw image Many *
Japanese FDI .mdi (MO)
.zdi (ZIP)

* Raw images come in many extensions, including: img ima

CD-ROM / DVD-ROM optical disc images

Supported formats:

Format File extension
Cue sheet .cue + .bin
ISO .iso

CD audio

Compact Disc Digital Audio (CDDA) playback through the emulated CD-ROM drive is supported on Cue sheet images. Audio output is muted on all drives by default; it can be unmuted by unchecking the Mute option for the respective drive on the status bar or Media menu.


Only raw format (.bin) tracks are supported. Compressed or otherwise encapsulated audio tracks (.wav, .mp3, .ogg, .flac and other formats) are not supported.