20 are emulators for the Nintendo Game Boy and Nintendo Entertainment System (NES).
21 They execute the romfile given as an argument.
22 The \fBz\fR, \fBx\fR, return and shift keys correspond to B, A, Start and Select, respectively.
26 Save the current state in \fBgb.save\fR / \fBnes.save\fR.
29 Load the current state from \fBgb.save\fR / \fBnes.save\fR.
40 Scale the screen by the given factor.
47 Save contents of battery backed SRAM (used by some games for savegames) as a file (\fIgb\fR automatically detects if this is needed)
51 Hide the top and bottom eight pixels (overscan area), like a real television would.
60 first appeared in 9front (April, 2012).
63 first appeared in 9front (February, 2014).