M devices/terminal.c → devices/terminal.c

@@ -15,7 +15,7 @@ {
     case TERMINAL_INPUT:
     {
         xyw_word handler;
-        if (!xyw_arguments_processed)
+        if (!xyw_arguments_processed && XYW_PEEKW(&data[TERMINAL_ON_ARGUMENT]))
         {
             // Process input as arguments (separated by XYW_ARGUMENT_SEPARATOR) until XYW_END_OF_ARGUMENTS
             handler = XYW_PEEKW(&data[TERMINAL_ON_ARGUMENT]);

M xywrun.c → xywrun.c

@@ -50,6 +50,7 @@ XYW_ERROR_STACK_OVERFLOW,
 } xyw_error;
 
 #define SYSTEM_STATE_RUNNING 0x01
+#define SYSTEM_STATE_WAITING 0x02
 #define SYSTEM_STATE_DEBUG 0x40
 #define SYSTEM_STATE_ERROR 0x80
 
@@ -291,13 +292,28 @@ // ...
 };
 // clang-format on
 
+static int system_error_state()
+{
+    return xyw_memory[SYSTEM_STATE] & SYSTEM_STATE_ERROR;
+}
+
+static int system_running_state()
+{
+    return xyw_memory[SYSTEM_STATE] & SYSTEM_STATE_RUNNING;
+}
+
+static int system_waiting_state()
+{
+    return xyw_memory[SYSTEM_STATE] & SYSTEM_STATE_WAITING;
+}
+
 //// Internal VM state
 xyw_byte error_handler_entry_s = 0;
 
-int process_events()
+static int process_events()
 {
     // Error handling
-    if (xyw_memory[SYSTEM_ERROR] != XYW_ERROR_NONE && !(xyw_memory[SYSTEM_STATE] & SYSTEM_STATE_ERROR))
+    if (xyw_memory[SYSTEM_ERROR] != XYW_ERROR_NONE && !system_error_state())
     {
         xyw_word on_error_handler = XYW_PEEKW(&xyw_memory[SYSTEM_ON_ERROR]);
         // If an error handler is set, jump to it
@@ -318,7 +334,7 @@ }
     }
     // Process terminal arguments if not already done
     static int argument_processing_active = 0;
-    if (!xyw_arguments_processed && !argument_processing_active && XYW_PEEKW(&xyw_memory[TERMINAL_ON_ARGUMENT]) && !(xyw_memory[SYSTEM_STATE] & SYSTEM_STATE_ERROR))
+    if (!xyw_arguments_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++)
@@ -351,7 +367,7 @@ if (xyw_memory[SYSTEM_STATE] & xyw_debug)
     {
         xyw_memory[SYSTEM_STATE] |= SYSTEM_STATE_DEBUG;
     }
-    while ((xyw_memory[SYSTEM_STATE] & SYSTEM_STATE_RUNNING) && *pc < SYSTEM_MEMORY_START)
+    while ((system_running_state()) && *pc < SYSTEM_MEMORY_START)
     {
         process_events();
         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);
@@ -405,7 +421,7 @@ /* JSR */ OPC_SR1(0x1E, xyw_word addr = ADDR(ARG),  ss_pushw(*pc+1); *pc = addr-1;);
             /* RTS */ case 0x1F: 
                 *pc = ss_popw()-1; 
                 // If returning from error handler, clear flag to allow re-trigger
-                if ((xyw_memory[SYSTEM_STATE] & SYSTEM_STATE_ERROR) && *s == error_handler_entry_s) {
+                if ((system_error_state()) && *s == error_handler_entry_s) {
                     xyw_memory[SYSTEM_STATE] &= ~SYSTEM_STATE_ERROR;
                     error_handler_entry_s = 0;
                 }
@@ -456,14 +472,16 @@ xyw_word on_keypress_handler = XYW_PEEKW(&xyw_memory[TERMINAL_ON_KEYPRESS]);
         if (on_keypress_handler)
         {
             xyw_dbg("terminal.on_keypress handler set to %04X, entering input loop\n", on_keypress_handler);
-            while (xyw_memory[SYSTEM_STATE] & SYSTEM_STATE_RUNNING)
+            while (system_running_state() || system_waiting_state())
             {
+                xyw_memory[SYSTEM_STATE] |= SYSTEM_STATE_WAITING;
                 int c = getch();
                 // if CTRL+C or CTRL+D is pressed, exit
                 if (c == 3 || c == 4)
                 {
                     return 0;
                 }
+                xyw_memory[SYSTEM_STATE] |= SYSTEM_STATE_RUNNING;
                 write(TERMINAL_INPUT, (xyw_byte)c);
             }
         }