Makes an alias of character string 2 as character string 1 -- in other words, after the declaration you can refer to character string 2 as character string 1 in all cases.
EX)
stralias man_a0 ":a/10,20,2;man_alpha.bmp"
Now, instead of typing in ":a/10,20,2;man_alpha.bmp", you can type in man_a0.
For instance, now ld c,man_a0,1 is equivalent to ld c,":a/10,20,2;man_alpha.bmp",1.