Golf-Basic 84, 88 characters

:0_A:0_O:1_I:2_D:3_S:O_C:I_X:S_Kl`1i`N@A=256:0_A@N=0d`A@N=1:A+1_A@N=2:A-1_A@N=3:A^2_Ag`1

Prompts one command at a time, as in at least 3 other solutions. Here is a test run for xiskisc:

?X
?I
?S
?K
?I
?S
?C
             289

Also, xiskso outputs 0, as it should.