.TH IO 1 .SH NAME io \- access PC I/O registers .SH SYNOPSIS .B io [ .B -WLMErw ] .I address [ .I value ] .SH DESCRIPTION .I io accesses PC I/O space. The operation to be performed is selected with .B -r or .B -w for reading or writing, respectively. The default operation size is a byte. C style notation for integers (e.g. .B 0x42 or .BR 023 ) is accepted for the .I address and .I value parameters. .PP .TP .B -W Perform a word (16 bit) operation. .TP .B -L Perform a long / double word (32 bit) operation. .TP .B -M Access a 64 bit wide machine specific register (MSR). .TP .B -E Access embedded controller space. .SH SOURCE .B /sys/src/cmd/io.c .SH SEE ALSO .IR seg (1), .IR arch (3) .SH HISTORY .I Io first appeared in 9front (April, 2011).