From: Maik Merten Date: Sat, 21 Dec 2019 15:11:38 +0000 (+0100) Subject: ps2: Add an example of PS/2 keyboard communication, update README X-Git-Url: https://sigrok.org/gitweb/?a=commitdiff_plain;h=16931eb480ba5df923c1508f3d83719eddcc5ab3;p=sigrok-dumps.git ps2: Add an example of PS/2 keyboard communication, update README This is an example of PS/2 keyboard communication where the receiving controller remains passive. --- diff --git a/ps2/keyboard/README b/ps2/keyboard/README index 47ddf17..640324c 100644 --- a/ps2/keyboard/README +++ b/ps2/keyboard/README @@ -7,8 +7,8 @@ This is a collection of PS/2 keyboard communication examples. A random PS/2 keyboard and a random PC mainboard were used as data source. For details see: -http://www.computer-engineering.org/ps2protocol/ -http://www.computer-engineering.org/ps2keyboard/ +https://web.archive.org/web/20161231114842/http://www.computer-engineering.org/ps2protocol/ +https://www.avrfreaks.net/sites/default/files/PS2%20Keyboard.pdf Logic analyzer setup @@ -28,3 +28,18 @@ ps2_keyboard_asdfgh.sr This file contains a sequence of keypresses on a standard PS/2 keyboard: a, s, d, f, g. The dump contains the "make code" and "break code" of each key. +After each transmission, the receiving controller appears to pull the clock +line low for more than 100 microseconds. This inhibits transmission until the +clock line is released, presumably because the receiving controller needs time +to process data. Due to this, additional very short clock pulses can be +observed, as the controller starts inhibiting communication only shortly after +packets are received. + + +ps2_keyboard_asdfgh_no_inhibit.sr +--------------------------------- + +The keys a, s, d, f and g pressed on a random PS/2 keyboard. + +In this dump, the receiving end was passive, without inhibiting communication. +Thus only clock pulses produced by the keyboard can be observed. diff --git a/ps2/keyboard/ps2_keyboard_asdfgh_no_inhibit.sr b/ps2/keyboard/ps2_keyboard_asdfgh_no_inhibit.sr new file mode 100644 index 0000000..3a33f85 Binary files /dev/null and b/ps2/keyboard/ps2_keyboard_asdfgh_no_inhibit.sr differ