What does “Legacy USB Mouse” support in a BIOS mean

biosmouseusb

What does a "Legacy USB Mouse" option in a BIOS mean?

Yes legacy usually means older revision, or obsolete. So legacy usb mouse means support for "old style usb mouses".

That's not really answering the question. As Mr. Tamm, my high school electricity teacher, liked to say, "Yes, and oranges taste orangey."

What does legacy USB mouse support mean?

  • What is a legacy USB mouse?
  • There's an "old style" USB mouse?
  • What changed between what version of usb and what version of usb that made mice incompatible?
  • Why was the change made?
  • When was the change made?
  • Who made the change?
  • What was the virtue of the "new USB mouses" over the "old USB mouses"?

Put it another way:

What is the BIOS doing when "Legacy USB Mouse" option is enabled?
What is the BIOS doing when "Legacy USB Mouse" option is disabled?

See also

Best Answer

As I understand it, it's not the Mouse or Keyboard that's legacy (PS/2 hasn't changed, USB is backwards compatible with other USB versions), it's the Operating System - legacy mouse mode emulates a PS/2 or AT device when a USB mouse is used with a OS that doesn't support it.

Not the best source, but this seems to confirm that, as does the last post here.

From Platform Compatibility for USB Boot Devices on the Windows Hardware Development Center on MSDN:

Architecture of Legacy Support with Both USB and PS/2 Support

Legacy support is shown in Figure 1 for both USB and PS/2-compatibile support. Important features include:

  • The BIOS traps events from the USB keyboard and mouse and presents them to the system as PS/2-compatible devices.

  • The legacy operating system recognizes the USB keyboard and USB mouse as PS/2-compatible devices, with limitations imposed by the USB boot protocol.

Figure 1. Architecture for Legacy Support for USB and PS/2
ditto

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