*always* use synchronized output for every frame

this prevents "rolling bars" as described

Author: jquast

gambaterm/run.py

@@ -128,20 +128,23 @@ def run(
                 new_frame = False
                 # Check terminal size
                 new_size = app_session.output.get_size()
-                maybe_clear_prefix, maybe_clear_suffix = b"", b""
                 if new_size != (height, width):
-                    # Write video frame with clear sequence inside synchronized output mode (DEC
-                    # 2026) to prevent flicker, and, set last_frame as inverse of the current frame
-                    # to ensure a full redraw by the blitter
-                    maybe_clear_prefix = b"\033[?2026h\033[H\033[2J"
-                    maybe_clear_suffix = b"\033[?2026l"
+                    maybe_clear_seq = b"\033[H\033[2J"
                     height, width = new_size
                     refx, refy = get_ref(width, height, console)
                     last_frame = ~video
-                # Render frame
-                video_data = maybe_clear_prefix + blit(
-                    video, last_frame, refx, refy, width - 1, height, color_mode
-                ) + maybe_clear_suffix
+                else:
+                    maybe_clear_seq = b""
+                # Render frame with synchronized output mode (DEC 2026) to prevent flickering
+                # when the screen is cleared, or an artificial CRT-like "rolling band" side-effects
+                # from fast "sprite blinking" meant to cause "transparency" effect on original HW,
+                # https://zladx.github.io/posts/links-awakening-partial-translucency
+                video_data = (
+                    b"\033[?2026h"
+                    + maybe_clear_seq
+                    + blit(video, last_frame, refx, refy, width - 1, height, color_mode)
+                    + b"\033[?2026l"
+                )
                 last_frame = video.copy()
                 # Update reporting
                 data_length.append(len(video_data))