Key is Scancode 0x2B, or as a VKEY code: VK_OEM_5 (0xDC)

Javascript says the key I pressed was keycode 220 (same number as 0xDC) or key "\".

I had Tandy 1000 as the selected machine. When I look at the onscreen keyboard, I don't see a backslash key underneath backspace, but I do see one next to left shift. For keyboards that have the alternate backslash there, it is listed as having a scancode of 0x56 and a VKEY code of VK_OEM_102 (0xE2). (I haven't actually checked information specific to the actual Tandy keyboard)