@@ -218,3 +218,14 @@ clock_timer_elapsed_pending = 0;
         }
     }
 }
+
+int clock_check_elapsed(void)
+{
+    clock_get_timer_value(); // triggers pending flag if target time has passed
+    if (clock_timer_elapsed_pending)
+    {
+        clock_timer_elapsed_pending = 0;
+        return 1;
+    }
+    return 0;
+}

@@ -3,3 +3,4 @@ 
 void clock_setup(xyw_byte *data);
 xyw_byte clock_input(xyw_byte *data, xyw_byte addr, xyw_byte *error);
 void clock_output(xyw_byte *data, xyw_byte addr, xyw_byte *error);
+int clock_check_elapsed(void);

@@ -35,9 +35,9 @@ }
 
     raw = terminal_orig_termios;
     raw.c_lflag &= ~(ICANON | ECHO | ISIG);
-    // Read returns as soon as 1 byte is available, no inter-byte timeout
-    raw.c_cc[VMIN] = 1;
-    raw.c_cc[VTIME] = 0;
+    // Non-blocking read: return after 100ms even if no input (for polling)
+    raw.c_cc[VMIN] = 0;
+    raw.c_cc[VTIME] = 1;
 
     if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw) != 0)
     {

@@ -0,0 +1,140 @@ 
+.include "lib/macros.xyw"
+
+; Clock REPL - demonstrates simultaneous keypress + timer handling.
+; The prompt shows a live clock [HH:MM:SS] that updates every second
+; while accepting keyboard input. Type a line and press Enter to echo it.
+
+; Main program: show initial prompt, register both handlers, halt
+print-prompt JSRw
+setup-handlers JSRw
+HLT
+
+.include "lib/putd.xyw"
+.include "lib/puts.xyw"
+
+; Register keypress and timer handlers, start 1-second timer
+; --
+.label setup-handlers
+  on-keypress terminal.on_keypress STW
+  on-timer clock.on_timer STW
+  $0100 clock.timer STW
+  RTS
+
+; Timer handler: redraw the prompt line with updated clock
+; --
+.label on-timer
+  redraw-line JSRw
+  $0100 clock.timer STW
+  RTS
+
+; Keypress handler
+; --
+.label on-keypress
+  terminal.input LDB
+  ; Enter
+  DUP $0D EQU on-enter JCNw
+  DUP $0A EQU on-enter JCNw
+  ; Backspace (DEL or BS)
+  DUP $7F EQU on-backspace JCNw
+  DUP $08 EQU on-backspace JCNw
+  ; Ignore non-printable
+  DUP $20 LTH on-ignore JCNw
+  ; Ignore if buffer full (48 chars)
+  buf-len LDBw $30 EQU on-ignore JCNw
+  ; Store char in buffer at buf[len]
+  DUP
+  buf-len LDBw $00 SWP buf ADDw STBw
+  ; Increment length
+  buf-len LDBw INC buf-len STBw
+  ; Echo the character
+  PUTC
+  RTS
+
+.label on-ignore
+  POP RTS
+
+; Enter: echo back the line
+; --
+.label on-enter
+  POP
+  NL
+  echo-prefix puts JSRw
+  print-buffer JSRw
+  NL
+  ; Clear buffer
+  $00 buf-len STBw
+  ; Show fresh prompt
+  print-prompt JSRw
+  RTS
+
+; Backspace: remove last character
+; --
+.label on-backspace
+  POP
+  buf-len LDBw $00 EQU on-backspace.done JCNw
+  buf-len LDBw DEC buf-len STBw
+  $08 PUTC $20 PUTC $08 PUTC
+  .label on-backspace.done
+    RTS
+
+; Print the clock prompt: [HH:MM:SS] > 
+; --
+.label print-prompt
+  $5B PUTC
+  clock.hour LDB ZEROPADx JSRw
+  $3A PUTC
+  clock.minute LDB ZEROPADx JSRw
+  $3A PUTC
+  clock.second LDB ZEROPADx JSRw
+  $5D PUTC SP $3E PUTC SP
+  RTS
+
+; Redraw current line in-place: CR + prompt + buffer + clear-to-EOL
+; --
+.label redraw-line
+  $0D PUTC
+  print-prompt JSRw
+  print-buffer JSRw
+  ; ANSI escape: ESC[K (clear to end of line)
+  $1B PUTC $5B PUTC $4B PUTC
+  RTS
+
+; Print buffer contents (buf[0..len-1])
+; -[xw, y]-
+.label print-buffer
+  buf POPxw
+  buf-len LDBw POPy
+  .label print-buffer.loop
+    PSHy $00 EQU print-buffer.done JCNw
+    LDBxw PUTC
+    INCxw DECy
+    print-buffer.loop JMPw
+  .label print-buffer.done
+    RTS
+
+; Print 8-bit value with leading zero if < 10
+; a8 -[x]-
+.label ZEROPADx
+  POPx PSHx $0A LTH zeropad.zero JCNw
+  .label zeropad.digit
+    PSHx putd JSRw
+    RTS
+  .label zeropad.zero
+    $30 PUTC
+    zeropad.digit JMPw
+
+; --- Data ---
+
+.label echo-prefix
+  .string "< "
+
+.label buf-len
+  .byte $00
+
+.label buf
+  .byte $00 $00 $00 $00 $00 $00 $00 $00
+  .byte $00 $00 $00 $00 $00 $00 $00 $00
+  .byte $00 $00 $00 $00 $00 $00 $00 $00
+  .byte $00 $00 $00 $00 $00 $00 $00 $00
+  .byte $00 $00 $00 $00 $00 $00 $00 $00
+  .byte $00 $00 $00 $00 $00 $00 $00 $00

@@ -21,6 +21,8 @@ 
 #define MAX_IMAGE_EXEC_DEPTH 8
 #define MAX_IMAGE_EXEC_PATH_LENGTH 256
 
+#define POLL_INTERVAL_MS 100
+
 /* system device addresses */
 #define SYSTEM_STATE 0xff00
 #define SYSTEM_ERROR 0xff01
@@ -40,15 +42,20 @@ 
 #ifdef _WIN32
 #include <conio.h>
 #include <windows.h>
-int getch()
+int getch_timeout(int timeout_ms)
 {
-    return _getch();
+    HANDLE h = GetStdHandle(STD_INPUT_HANDLE);
+    if (WaitForSingleObject(h, timeout_ms) == WAIT_OBJECT_0 && _kbhit())
+        return _getch();
+    return 0;
 }
 #else
 #include <unistd.h>
-int getch()
+int getch_timeout(int timeout_ms)
 {
-    return getchar();
+    (void)timeout_ms; // bounded by VMIN=0/VTIME in terminal_init()
+    int c = getchar();
+    return (c == EOF) ? 0 : c;
 }
 #endif
 typedef enum
@@ -673,31 +680,44 @@ *pc = on_arg_handler;
         return 1;
     }
 
-    // Keypress handling
+    // Keypress handling (non-blocking: returns 0 on timeout)
     xyw_word on_keypress_handler = XYW_PEEKW(&xyw_memory[TERMINAL_ON_KEYPRESS]);
-    if (on_keypress_handler)
-    {
-        int c = getch();
-        if (c == 3 || c == 4) return 0; // CTRL+C or CTRL+D
-        xyw_memory[TERMINAL_INPUT] = (xyw_byte)c;
-        xyw_memory[SYSTEM_STATE] |= SYSTEM_STATE_RUNNING;
-        // Sentinel return: handler's RTS returns to device space, cleanly ending dispatch
-        ss_push_frame(DEVICE_AREA_START);
-        *pc = on_keypress_handler;
-        return 1;
-    }
 
-    // Timer handling (readb blocks until the timer elapses if active)
+    // Timer handling
     xyw_word on_timer_handler = XYW_PEEKW(&xyw_memory[CLOCK_ON_TIMER_ELAPSED]);
-    if (on_timer_handler)
+
+    // Polling loop: keep checking until an event fires or exit is requested
+    while (on_keypress_handler || on_timer_handler)
     {
-        if (readb(CLOCK_ON_TIMER_ELAPSED))
+        if (on_keypress_handler)
+        {
+            int c = getch_timeout(POLL_INTERVAL_MS);
+            if (c > 0)
+            {
+                if (c == 3 || c == 4) return 0; // CTRL+C or CTRL+D
+                xyw_memory[TERMINAL_INPUT] = (xyw_byte)c;
+                xyw_memory[SYSTEM_STATE] |= SYSTEM_STATE_RUNNING;
+                // Sentinel return: handler's RTS returns to device space, cleanly ending dispatch
+                ss_push_frame(DEVICE_AREA_START);
+                *pc = on_keypress_handler;
+                return 1;
+            }
+            // c == 0: no key this cycle — fall through to timer check
+        }
+
+        if (on_timer_handler)
         {
-            xyw_memory[SYSTEM_STATE] |= SYSTEM_STATE_RUNNING;
-            // Sentinel return: handler's RTS returns to device space, cleanly ending dispatch
-            ss_push_frame(DEVICE_AREA_START);
-            *pc = on_timer_handler;
-            return 1;
+            int elapsed = on_keypress_handler
+                ? clock_check_elapsed()          // non-blocking: keypress handler also armed
+                : readb(CLOCK_ON_TIMER_ELAPSED); // blocking: timer-only program
+            if (elapsed)
+            {
+                xyw_memory[SYSTEM_STATE] |= SYSTEM_STATE_RUNNING;
+                // Sentinel return: handler's RTS returns to device space, cleanly ending dispatch
+                ss_push_frame(DEVICE_AREA_START);
+                *pc = on_timer_handler;
+                return 1;
+            }
         }
     }