Interrupt system implemented, some new programs.

Programs/testPrograms/swiFaultTest.asm

@@ -0,0 +1,30 @@
+; Tests a software interrupt that names a vector with nothing installed in it.
+;
+; Until the assembler can lay down a vector table, every entry reads as zero, and zero
+; means no handler. Dispatching through one has to stop the machine and say which
+; vector was empty, rather than jumping to the bottom of Program Memory and running
+; whatever happens to be sitting there.
+;
+; The letter is printed first so that it is obvious the program ran at all, and that it
+; stopped exactly where it should have.
+;
+; Correct output is:
+;   O
+;   a fault naming software vector 20, and a non zero exit.
+
+#Program
+
+start:
+  INIA 0d79         ; 'O'
+  OUTA 0x00
+  INIA 0x0A
+  OUTA 0x00
+
+  SWI 0d20          ; Nothing is installed here.
+
+  ; Never reached. If the machine ever prints this, the empty vector was taken.
+  INIA 0d88         ; 'X'
+  OUTA 0x00
+  INIA 0x0A
+  OUTA 0x00
+  HALT