Successful first run of B interpreter!

I hand compiled hello.b into hello.s and assembled with the interpreter
and runtime library:
perl as7 --out a.out bl.s hello.s bi.s

src/other/hello.b

@@ -0,0 +1,9 @@
+main $(
+  write('He');
+  write('ll');
+  write('o,');
+  write(' W');
+  write('or');
+  write('ld');
+  write('!*n');
+$)

src/other/hello.s

@@ -0,0 +1,40 @@
+.main: .+1
+ s 2
+ x .write
+ n 2    " etcop mark
+ n 5    " etcop litrl
+ 36965
+ n 3    " etcop call
+ x .write
+ n 2    " etcop mark
+ n 5    " etcop litrl
+ 55404
+ n 3    " etcop call
+ x .write
+ n 2    " etcop mark
+ n 5    " etcop litrl
+ 56876
+ n 3    " etcop call
+ x .write
+ n 2    " etcop mark
+ n 5    " etcop litrl
+ 16471
+ n 3    " etcop call
+ x .write
+ n 2    " etcop mark
+ n 5    " etcop litrl
+ 56946
+ n 3    " etcop call
+ x .write
+ n 2    " etcop mark
+ n 5    " etcop litrl
+ 55396
+ n 3    " etcop call
+ x .write
+ n 2    " etcop mark
+ n 5    " etcop litrl
+ 16906
+ n 3    " etcop call
+ x .flush
+ n 1    " etcop mcall
+ n 7    " etcop retrn