Warm boot on Ctrl-C at the start of a line #17

src/bdos.rs

@@ -156,7 +156,10 @@ impl Bdos {
                     bdos_console::write_string(env, arg16);
                 },
                 10 => { // C_READSTR
-                    bdos_console::read_string(env, arg16);
+                    let result = bdos_console::read_string(env, arg16);
+                    if result == ExecutionResult::Continue{
+                        return result;
+                    }
                 },
                 11 => { // C_STAT - Console status
                     res8 = Some(bdos_console::status(env));

src/bdos_console.rs

@@ -1,4 +1,6 @@
 use iz80::Machine;
+use crate::ExecutionResult;
+
 use super::bdos_environment::*;
 
 pub fn read(env: &mut BdosEnvironment) -> u8 {
@@ -38,7 +40,7 @@ pub fn write_string(env: &mut BdosEnvironment, address: u16) {
     }
 }
 
-pub fn read_string(env: &mut BdosEnvironment, address: u16) -> u8 {
+pub fn read_string(env: &mut BdosEnvironment, address: u16) -> ExecutionResult {
     // The Read Buffer function reads a line of edited console input into a
     // buffer addressed by registers DE. Console input is terminated when either
     // input buffer overflows or a carriage return or line-feed is typed. The
@@ -62,6 +64,12 @@ pub fn read_string(env: &mut BdosEnvironment, address: u16) -> u8 {
         if ch == 10 || ch == 13 { // CR of LF
             break;
         }
+
+        // break on control-c at the start of the line
+        if ch == 3 && size == 0 {
+            return ExecutionResult::WarmBoot
+        }
+
         if ch == 127 { // DEL
             if size > 0 {
                 size -= 1;
@@ -79,7 +87,7 @@ pub fn read_string(env: &mut BdosEnvironment, address: u16) -> u8 {
     }
 
     env.machine.poke(address + 1, size);
-    size
+    ExecutionResult::Continue
 }
 
 pub fn status(env: &mut BdosEnvironment) -> u8 {