Interrupt system implemented, some new programs.

2026-08-15 00:44:13 -04:00
parent 638b68b25c
commit 6d1966d500
79 changed files with 2778 additions and 88 deletions
@@ -0,0 +1,36 @@
+; Tests MVSD, which copies the Stack Pointer into a Data Pointer.
+;
+; The Stack Pointer still cannot be written, so this does not let a program move the
+; Stack. It lets a program find it, which is what reading anything already on the Stack
+; requires. Without it, the manual's claim that a Data Pointer can be aimed at the Stack
+; is not something a program can actually act on: there is no way to learn where the
+; Stack is without already knowing.
+;
+; An interrupt handler needs this to reach its own frame, which is how a fault handler
+; steps over the byte that failed and carries on.
+;
+; Correct output is:
+;   OK
+
+#Program
+
+start:
+  ; Push two bytes, then go looking for them.
+  INIA 0d79         ; 'O'
+  PSHA
+  INIA 0d75         ; 'K'
+  PSHA
+
+  ; The Stack Pointer points at the next free slot, so the byte pushed last sits one
+  ; above it, and the one before that sits two above.
+  MVSD.0
+  DPUP.0 0d01
+  LDA.0             ; 'K', the last one pushed.
+  INCD.0
+  LDB.0             ; 'O', the one before it.
+
+  OUTB 0x00
+  OUTA 0x00
+  INIA 0x0A
+  OUTA 0x00
+  HALT