1*d88ce912SThomas HuthVNC LED state Pseudo-encoding 2*d88ce912SThomas Huth============================= 3*d88ce912SThomas Huth 4*d88ce912SThomas HuthIntroduction 5*d88ce912SThomas Huth------------ 6*d88ce912SThomas Huth 7*d88ce912SThomas HuthThis document describes the Pseudo-encoding of LED state for RFB which 8*d88ce912SThomas Huthis the protocol used in VNC as reference link below: 9*d88ce912SThomas Huth 10*d88ce912SThomas Huthhttp://tigervnc.svn.sourceforge.net/viewvc/tigervnc/rfbproto/rfbproto.rst?content-type=text/plain 11*d88ce912SThomas Huth 12*d88ce912SThomas HuthWhen accessing a guest by console through VNC, there might be mismatch 13*d88ce912SThomas Huthbetween the lock keys notification LED on the computer running the VNC 14*d88ce912SThomas Huthclient session and the current status of the lock keys on the guest 15*d88ce912SThomas Huthmachine. 16*d88ce912SThomas Huth 17*d88ce912SThomas HuthTo solve this problem it attempts to add LED state Pseudo-encoding 18*d88ce912SThomas Huthextension to VNC protocol to deal with setting LED state. 19*d88ce912SThomas Huth 20*d88ce912SThomas HuthPseudo-encoding 21*d88ce912SThomas Huth--------------- 22*d88ce912SThomas Huth 23*d88ce912SThomas HuthThis Pseudo-encoding requested by client declares to server that it supports 24*d88ce912SThomas HuthLED state extensions to the protocol. 25*d88ce912SThomas Huth 26*d88ce912SThomas HuthThe Pseudo-encoding number for LED state defined as: 27*d88ce912SThomas Huth 28*d88ce912SThomas Huth======= =============================================================== 29*d88ce912SThomas HuthNumber Name 30*d88ce912SThomas Huth======= =============================================================== 31*d88ce912SThomas Huth-261 'LED state Pseudo-encoding' 32*d88ce912SThomas Huth======= =============================================================== 33*d88ce912SThomas Huth 34*d88ce912SThomas HuthLED state Pseudo-encoding 35*d88ce912SThomas Huth-------------------------- 36*d88ce912SThomas Huth 37*d88ce912SThomas HuthThe LED state Pseudo-encoding describes the encoding of LED state which 38*d88ce912SThomas Huthconsists of 3 bits, from left to right each bit represents the Caps, Num, 39*d88ce912SThomas Huthand Scroll lock key respectively. '1' indicates that the LED should be 40*d88ce912SThomas Huthon and '0' should be off. 41*d88ce912SThomas Huth 42*d88ce912SThomas HuthSome example encodings for it as following: 43*d88ce912SThomas Huth 44*d88ce912SThomas Huth======= =============================================================== 45*d88ce912SThomas HuthCode Description 46*d88ce912SThomas Huth======= =============================================================== 47*d88ce912SThomas Huth100 CapsLock is on, NumLock and ScrollLock are off 48*d88ce912SThomas Huth010 NumLock is on, CapsLock and ScrollLock are off 49*d88ce912SThomas Huth111 CapsLock, NumLock and ScrollLock are on 50*d88ce912SThomas Huth======= =============================================================== 51