MEM 0040h:0097h - KEYBOARD STATUS BYTE 2
Size: BYTE
SeeAlso: MEM 0040h:0096h,INT 16/AH=11h
Bitfields for keyboard status byte 2:
Bit(s) Description (Table M0034)
7 =1 keyboard transmit error flag
6 =1 LED update in progress
5 =1 RESEND received from keyboard
4 =1 ACK received from keyboard
3 reserved, must be zero
2 Caps Lock LED
1 Num Lock LED
0 Scroll Lock LED
SeeAlso: #M0033,#M0010
PORT 0060-006F - KEYBOARD CONTROLLER 804x (8041, 8042) (or PPI (8255) on PC,XT)
Note: XT uses ports 60h-63h, AT uses ports 60h-64h
0060 RW KB controller data port or keyboard input buffer (ISA, EISA)
should only be read from after status port bit0 = 1
should only be written to if status port bit1 = 0
0060 R- KeyBoard or KB controller data output buffer (via PPI on XT)
PC: input from port A of 8255, if bit7 in 61h set (see #P0396)
get scancodes, special codes (in PC: with bit7 in 61h cleared)
(see #P0390)
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Values for keyboard commands (data also goes to PORT 0060h):
Value Count Description
EDh double set/reset mode indicators Caps Num Scrl
bit 2 = CapsLk, bit 1 = NumLk, bit 0 = ScrlLk
all other bits must be zero.