zxvideo: fix scrolling clearing of bottom line

Missed a case when adjusting for banked calls

diff --git a/Kernel/platform-zx128/zxvideo.s b/Kernel/platform-zx128/zxvideo.s
index f411735..4869ba9 100644 (file)
--- a/Kernel/platform-zx128/zxvideo.s
+++ b/Kernel/platform-zx128/zxvideo.s
@@ -96,8 +96,9 @@ clear_next_line:
         ld c, #32           ; clear 32 cols
         push bc
         push de
+       push af
         call _clear_across
-
+       pop af
         pop hl              ; clear stack
         pop hl