Tertiary and quaternary IDE

The additional tertiary and quaternary IDE controllers, enabled through the Storage controllers settings page, are not supported by all emulated BIOSes and may require manual configuration of emulated operating systems. The specific details are outlined on this page.

System resources

The following resources are used by these additional controllers:

Channel Main I/O port Status I/O port IRQ
Tertiary 0168h 036Eh 10
Quaternary 01E8h 03EEh 11

These controllers are not Plug and Play compliant. If the emulated machine supports Plug and Play (through ISA, PCI or other means), remember to mark the IRQ(s) as being used by a legacy ISA device in the BIOS setup utility.


While the IRQ for each channel can be changed through its respective Settings button on Tertiary / Quaternary IDE Controller, many operating systems do not allow legacy (ISA or VLB) IDE controllers to use custom IRQs.

BIOS support

The tertiary and quaternary channels are not visible and not bootable by any BIOS currently emulated by 86Box. The only exception is MR BIOS version 3, which provides full support for them, including bootability and INT 13h services.

Operating system support

DOS and real mode

DOS and other real mode operating systems rely on INT 13h services provided by the BIOS to access hard disks. These are only provided for the tertiary and quaternary channels by MR BIOS version 3, as mentioned above.

Windows 95, 98 and Me

The Windows 9x family will only detect and enable both additional channels during installation if the BIOS supports them. Each additional channel can be enabled after installation through the following steps:

  1. Go to the Add New Hardware control panel.
  2. Add a Standard IDE/ESDI Hard Disk Controller from the Hard disk controllers category.
  3. Don’t restart the system when asked to.
  4. Go to the Device Manager tab of the System control panel.
  5. Select the newly-added Standard IDE/ESDI Hard Disk Controller device from the Hard disk controllers category and click Properties.
  6. Go to the Resources tab.
  7. Select Basic configuration 4 in the Settings based on box.
  8. Change the resource settings to match the table above. The first Input/Output Range range corresponds to the main I/O port, the second one corresponds to the status I/O port, and Interrupt Request corresponds to the IRQ.
    • The status I/O port range is off by 6 units. Select 0368 for the tertiary channel or 03E8 for the quaternary channel.
    • The image below shows an example configuration for the tertiary channel.
  9. If both the tertiary and quaternary channels are enabled, repeat the steps above to add the other channel.

Windows NT, 2000 and XP

The Windows NT family (from 3.5 to XP) will automatically detect and enable both additional channels during installation, regardless of BIOS support. This auto-detection does not, however, work on machines with Award BIOS, except for the version which identifies itself as Phoenix - AwardBIOS v6.00PG, where it does work.


If you install the system to a hard disk on one of the additional channels, it will not be bootable if the BIOS doesn’t support booting from these channels.

On Windows 2000 only, the additional channels can be enabled after the system is installed through Add New Hardware similarly to Windows 95/98/Me above, although the I/O ports and IRQ cannot be changed. Basic configuration 0003 corresponds to the tertiary channel, while Basic configuration 0002 corresponds to the quaternary channel.

Windows Vista and 7

The Windows NT 6 family does not support legacy non-Plug-and-Play IDE controllers, and therefore cannot use the additional channels as currently emulated by 86Box.


On kernels with libata (typically 2.6.19 and newer), run the modprobe pata_legacy probe_all=1 command as root to enable both additional channels. Consult your distribution’s documentation on how to load that module on startup.

On kernels without libata (typically older than 2.6.19), add the following parameters to the kernel command line to enable their respective channels:

  • Tertiary: ide2=0x168,0x36e,10 (assuming IRQ 10)
  • Quaternary: ide3=0x1e8,0x3ee,11 (assuming IRQ 11)


Some Linux distributions may automatically detect and enable both additional channels; however, that is very rarely the case.