{"id":94385,"date":"2016-09-26T07:00:00","date_gmt":"2016-09-26T21:00:00","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/oldnewthing\/?p=94385"},"modified":"2019-03-13T11:07:12","modified_gmt":"2019-03-13T18:07:12","slug":"20160926-00","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/oldnewthing\/20160926-00\/?p=94385","title":{"rendered":"It says that I should use USB usage page 1 and usage 6 to get raw keyboard data, but what if I have a PS\/2 keyboard?"},"content":{"rendered":"

Some time ago, I wrote about raw input and noted that if you want to receive raw keyboard input, you set the usage page to 1 and the usage to 6, noting that these numbers come from the USB HID specification. Commenter onodera asks, “Does this work for PS\/2 input devices as well<\/a>?” <\/p>\n

Let’s try it. I happen to have a laptop within easy reach, so I plugged in an external USB wireless keyboard, then went to Device Manager. It says <\/p>\n

\n
⌵ ⌨ Keyboards<\/div>\n
⌨ Standard PS\/2 Keyboard<\/div>\n
⌨ Wireless Keyboard Filter Device<\/div>\n<\/p><\/div>\n

Then I ran the sample raw keyboard input program from the same article<\/a> and pressed the space bar a few times on the external USB wireless keyboard, then the space bar a few times on the built-in PS\/2 keyboard: <\/p>\n

\n04E00817, msg=0100, vk=0020, scanCode=39, press\n04E00817, msg=0101, vk=0020, scanCode=39, release\n04E00817, msg=0100, vk=0020, scanCode=39, press\n04E00817, msg=0101, vk=0020, scanCode=39, release\n04E00817, msg=0100, vk=0020, scanCode=39, press\n04E00817, msg=0101, vk=0020, scanCode=39, release\n0001003D, msg=0100, vk=0020, scanCode=39, press\n0001003D, msg=0101, vk=0020, scanCode=39, release\n0001003D, msg=0100, vk=0020, scanCode=39, press\n0001003D, msg=0101, vk=0020, scanCode=39, release\n0001003D, msg=0100, vk=0020, scanCode=39, press\n0001003D, msg=0101, vk=0020, scanCode=39, release\n<\/pre>\n
The entries from device 04E00817<\/code> are from the external USB wireless keyboard. The entries from device 0001003D<\/code> are from the built-in PS\/2 keyboard. <\/p>\n
So there you go: It works even for PS\/2 keyboards. <\/p>\n
The fact that the input is described in terms of HID usage pages and HID usages is just a convenient way of expressing what kind of input you want, because it generalizes in the obvious way to to HID devices. Non-HID devices are mapped to the corresponding HID usages. <\/p>\n
Bonus chatter<\/b>: Raw input also captures synthesized input. Here’s the result after performing a Send­Input<\/code> to simulate pressing the space bar: <\/p>\n
\n00000000, msg=0100, vk=0020, scanCode=39, press\n00000000, msg=0101, vk=0020, scanCode=39, release\n<\/pre>\n
Notice that this was a completely synthetic keypress, but it showed up anyway, despite not having come from a USB device (or indeed any device at all). Note also that the device handle is null. <\/p>\n","protected":false},"excerpt":{"rendered":"
The numbers came from the USB HID specification, but that doesn’t require the keyboard to be USB.<\/p>\n","protected":false},"author":1069,"featured_media":111744,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[25],"class_list":["post-94385","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-oldnewthing","tag-code"],"acf":[],"blog_post_summary":"
The numbers came from the USB HID specification, but that doesn’t require the keyboard to be USB.<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/94385","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/users\/1069"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/comments?post=94385"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/94385\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media\/111744"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media?parent=94385"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/categories?post=94385"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/tags?post=94385"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}