Experimental fix for IF1 break problem.

Author: tschak909

src/io.c

@@ -26,6 +26,7 @@ struct hostent *he;
 char host_name[32];
 #endif
 
+extern unsigned char keyboard_break_pressed; // IF1 Break protection
 
 char io_initialized=0;
 extern unsigned char is_extend;  //bring in is_extend for borders
@@ -83,27 +84,32 @@ void io_main(void)
 {
 #ifdef __RS232__
 
-	//Don't try to wrap this in for Rasta bars, it just flashes every call to io_main.										
+  //Don't try to wrap this in for Rasta bars, it just flashes every call to io_main.
+
+  if (keyboard_break_pressed)
+    goto io_do_rx_only; // This has to be short circuited because of the extra keyboard scanning needed.
+  
   if (rs232_get(&inb) != RS_ERR_NO_DATA)  	// *IRQ-OFF (RECEIVING DATA)
     {	/* [RX - Display] */ 	
 #ifdef __SPECTRUM__
-        if(is_extend==1) {zx_border(INK_BLACK);}  else {zx_border(INK_WHITE);}	//RS232 Raster Bars- A little lie, the IO has been done.
+      if(is_extend==1) {zx_border(INK_BLACK);}  else {zx_border(INK_WHITE);}	//RS232 Raster Bars- A little lie, the IO has been done.
 #endif
-	ShowPLATO(&inb,1);
+      ShowPLATO(&inb,1);
 #ifdef __SPECTRUM__
-	if(is_extend==1) {zx_border(INK_GREEN);}  else {zx_border(INK_BLACK);}	//RS232 Raster Bars			
+      if(is_extend==1) {zx_border(INK_GREEN);}  else {zx_border(INK_BLACK);}	//RS232 Raster Bars			
 #endif
     }
   else
     {  /* [NO RX - KEY scan] */  
 #ifdef __SPECTRUM__
-	if(is_extend==1) {zx_border(INK_GREEN);}  else {zx_border(INK_BLACK);}	//RS232 Raster Bars
+    io_do_rx_only:
+      if(is_extend==1) {zx_border(INK_GREEN);}  else {zx_border(INK_BLACK);}	//RS232 Raster Bars
 #endif										 		
-	for(int Kscan=0;Kscan<30;Kscan++)  //Extra keyboard scanning					
-	  {
-	    keyboard_main();
-	  }
-
+      for(int Kscan=0;Kscan<30;Kscan++)  //Extra keyboard scanning					
+	{
+	  keyboard_main();
+	}
+      
     }
 #endif
 #ifdef __SPECTRANET__

src/keyboard.c

@@ -25,6 +25,13 @@ extern padBool TTY;
 static unsigned char ch;
 unsigned char is_extend=0;  //deleted static is used in IO.C now for Rasta bars
 
+// input.h internal state - for trapping verboten keys
+uchar in_KeyDebounce;
+uchar in_KeyStartRepeat;
+uchar in_KeyRepeatPeriod;
+uchar in_KbdState;
+uchar keyboard_break_pressed=false;
+
 /**
  * A simple key press feedback.
  */
@@ -74,6 +81,13 @@ void keyboard_out_tty(char ch)
  */
 void keyboard_main(void)
 {
+  // This snippet looks for break keyboard press, and sets a flag so that I/O doesn't call rs232_get when pressed, to
+  // avoid tripping over the ZX Interface 1's "break" functionality.
+  in_GetKeyReset();
+  keyboard_break_pressed=false;
+  if (in_KeyPressed==0x817F) // Look for BREAK key combination
+    keyboard_break_pressed=true;
+  
   ch=getk();	
   if (ch!=0x00)
     {