M xyw.h → xyw.h

@@ -31,6 +31,14 @@ xyw_input input;
     xyw_output output;
 } xyw_device;
 
+typedef struct
+{
+    xyw_word handler;
+    int pending;
+} xyw_vector_slot;
+
+void xyw_request_vector(xyw_word handler);
+
 // Main Globals
 extern xyw_device xyw_devices[XYW_TOTAL_DEVICES];
 extern const char xyw_instructions[][4];

M xywrun.c → xywrun.c

@@ -13,6 +13,7 @@ 
 #define USER_STACK_SIZE 128
 #define SYSTEM_FRAME_SIZE 8
 #define SYSTEM_MAX_FRAMES 48
+#define XYW_MAX_VECTORS 4
 
 #define USER_MEMORY_START 0x000
 #define DEVICE_AREA_START 0xff00
@@ -85,6 +86,9 @@ static xyw_word yw_storage = 0; // 16-bit Y register storage
 xyw_word *pc = &pc_storage;
 xyw_word *xw = &xw_storage;
 xyw_word *yw = &yw_storage;
+
+//// Vector slots
+static xyw_vector_slot vector_slots[XYW_MAX_VECTORS];
 
 //// Helpers to retrieve device number and address within the device
 static inline int get_device(xyw_word addr)
@@ -194,6 +198,39 @@ for (int i = 0; i < SYSTEM_FRAME_SIZE; i++) base[i] = 0;
     return return_addr;
 }
 
+//// Vector dispatch (deferred, non-recursive event handling)
+
+// Request a vector
+void xyw_request_vector(xyw_word handler)
+{
+    for (int i = 0; i < XYW_MAX_VECTORS; i++)
+    {
+        if (!vector_slots[i].pending)
+        {
+            vector_slots[i].handler = handler;
+            vector_slots[i].pending = 1;
+            return;
+        }
+    }
+    XYW_DBG("Vector table full, dropping request for handler %04X\n", handler);
+}
+
+// Dispatch requested vectors (called once per xyw_eval iteration)
+static void dispatch_vectors(void)
+{
+    for (int i = 0; i < XYW_MAX_VECTORS; i++)
+    {
+        if (vector_slots[i].pending)
+        {
+            vector_slots[i].pending = 0;
+            XYW_DBG("Dispatching vector to handler %04X\n", vector_slots[i].handler);
+            ss_push_frame(*pc);
+            *pc = vector_slots[i].handler - 1;
+            return; 
+        }
+    }
+}
+
 //// User stack management
 
 static void us_push(xyw_byte val)
@@ -388,32 +425,15 @@ if (on_timer_handler != 0)
     {
         if (readb(CLOCK_ON_TIMER_ELAPSED))
         {
-            XYW_DBG("Timer elapsed, jumping to handler at %04X\n", on_timer_handler);
-            xyw_eval(on_timer_handler);
+            XYW_DBG("Timer elapsed, requesting vector for handler at %04X\n", on_timer_handler);
+            xyw_request_vector(on_timer_handler);
         }
     }
-    // Process terminal arguments if not already done
-    static int argument_processing_active = 0;
-    if (!xyw_argv_processed && !argument_processing_active && XYW_PEEKW(&xyw_memory[TERMINAL_ON_ARGUMENT]) && !(system_error_state()))
-    {
-        argument_processing_active = 1; // Prevent re-entry
-        for (int i = 1; i < xyw_argc; i++)
-        {
-            XYW_DBG("Processing argument %d of %d: %s\n", i, xyw_argc, xyw_argv[i]);
-            const char *arg = xyw_argv[i];
-            for (size_t j = 0; arg[j] != '\0'; j++)
-            {
-                writeb(TERMINAL_INPUT, (xyw_byte)arg[j]);
-            }
-            if (i < xyw_argc - 1)
-            {
-                writeb(TERMINAL_INPUT, XYW_ARGUMENT_SEPARATOR);
-            }
-        }
-        writeb(TERMINAL_INPUT, XYW_END_OF_ARGUMENTS);
-        xyw_argv_processed = 1;
-        argument_processing_active = 0;
-    }
+
+    // TODO: Beeper playback-finished handling (need BEEPER_ON_FINISHED vector)
+    // xyw_word on_beeper_finished = XYW_PEEKW(&xyw_memory[BEEPER_ON_FINISHED]);
+    // if (on_beeper_finished != 0 && beeper_check_finished())
+    //     xyw_request_vector(on_beeper_finished);
 
     return 0;
 }
@@ -436,6 +456,7 @@ }
     while ((system_running_state()) && *pc < DEVICE_AREA_START)
     {
         process_events();
+        dispatch_vectors();
         XYW_DBG(" -- PC: %04X -> %02X (%s) [U:%02X|S:%02X|X:%02X|Y:%02X|XW:%04X|YW:%04X]\n", *pc, xyw_memory[*pc], xyw_instructions[xyw_memory[*pc] & 0x1F], u, s, *x, *y, *xw, *yw);
         switch (xyw_memory[*pc])
         {
@@ -537,6 +558,26 @@ 
     int eval_result = xyw_eval(0x0000);
     if (!eval_result)
     {
+        // Handle command line arguments
+        if (!xyw_argv_processed && !(system_error_state()) && XYW_PEEKW(&xyw_memory[TERMINAL_ON_ARGUMENT]))
+        {
+            for (int i = 1; i < xyw_argc; i++)
+            {
+                XYW_DBG("Processing argument %d of %d: %s\n", i, xyw_argc, xyw_argv[i]);
+                const char *arg = xyw_argv[i];
+                for (size_t j = 0; arg[j] != '\0'; j++)
+                {
+                    writeb(TERMINAL_INPUT, (xyw_byte)arg[j]);
+                }
+                if (i < xyw_argc - 1)
+                {
+                    writeb(TERMINAL_INPUT, XYW_ARGUMENT_SEPARATOR);
+                }
+            }
+            writeb(TERMINAL_INPUT, XYW_END_OF_ARGUMENTS);
+            xyw_argv_processed = 1;
+        }
+        
         // Check if we need to enter an event loop (keypress handler or timer)
         xyw_word on_keypress_handler = XYW_PEEKW(&xyw_memory[TERMINAL_ON_KEYPRESS]);
         xyw_word on_timer_handler = XYW_PEEKW(&xyw_memory[CLOCK_ON_TIMER_ELAPSED]);