Non-ASCII keystrokes

[Robb Bates]

Just looking at the VDA keyboard driver.

A few questions about the non-ascii keystrokes:

What is the "App" keystroke?  I don't see that on any standard 104 key keyboard.  Is that the Windows key?

What about Alt, Menu or Scroll Lock?

Robb

[Wayne Warthen]

Hi Robb,

On Sunday, June 1, 2025 at 10:19:30 AM UTC-7 Robb Bates wrote:

Just looking at the VDA keyboard driver.

A few questions about the non-ascii keystrokes:

What is the "App" keystroke?  I don't see that on any standard 104 key keyboard.  Is that the Windows key?

It is the weird key on the right next to the Ctrl key.  https://www.perkins.org/resource/using-applications-key-or-without-key/#:~:text=Let's%20start%20with%20where%20it,the%20right%20side%20control%20key.

What about Alt, Menu or Scroll Lock?

The modifier keys (like Alt) handled explicitly in the driver.  See KBD_DEC6.  It has some tricky optimizations.  Likewise, toggle keys (like Scroll Lock) are handled in KBD_DEC8.

The Menu key is a synonym for the App key (I think).  This is just handled as a "special" key mapped to 0xEF.  It is not the same as the Windows key.  The Windows key is a modifier key.

Thanks, Wayne

[Jonathan Harston]

See also:

https://mdfs.net/Docs/Comp/Keyboard/USB/HIDkeys.gif

and

https://mdfs.net/Docs/Comp/Keyboard/USB/HIDkeyJP.gif