Disk images

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

Hard disk images

Supported formats:

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

* Raw image extensions recognized by 86Box include: .hdd .ima .img

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 BIOS. The table below lists all important limits applicable to the IDE bus:

Limit Disk size Cylinders Heads Sectors
20-bit CHS 504 MB 1024 16 63
12-bit cylinder 2015 MB 4095 16 63
ECHS translation 4032 MB 1024 128 63
Revised ECHS 7560 MB 1024 240 63
LBA translation 8032 MB 1024 255 63
16-bit cylinder 32255 MB 65535 16 63
28-bit CHS 130558 MB 65535 255 63
86Box 131071 MB Not applicable

The maximum supported disk image size for IDE or SCSI is 131071 MB. Disk overlay software such as Ontrack Disk Manager can work around BIOS limits and allow booting of IDE hard drives within the 131071 MB limit, with the same caveats as using such software on a real machine.

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 image extensions recognized by 86Box include: .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 when accessing these, as an inaccurate BPB detection may result in read errors, data corruption and other issues.

Note

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 image extensions recognized by 86Box include: .ima .img

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 drives is supported on Cue sheet images. Audio output is enabled on the first CD-ROM drive and muted on subsequent drives by default; individual drives can be muted or unmuted through the status bar or Media menu.

Note

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

Cassette tape images

Supported formats:

Format File extension
Raw PCM audio Many *
PCE cassette .cas
Wave audio .wav

* Raw audio extensions recognized by 86Box include: .pcm .raw

PCjr cartridge images

Supported formats:

Format File extension
Raw image Many *
JRipCart .jrc

* Raw image extensions recognized by 86Box include: .a .b .bin