diff --git a/programs/emulator/chip8/emu.inc b/programs/emulator/chip8/emu.inc
index b7703b10f7..dbd3e0c45e 100644
--- a/programs/emulator/chip8/emu.inc
+++ b/programs/emulator/chip8/emu.inc
@@ -103,7 +103,7 @@ proc chip8_emulatecycle stdcall
         movzx   bx, byte [memory + 1 + ecx]
         or      ax, bx
         mov     word [opcode], ax
-        ; DEBUGF  DBG_INFO, "opcode = 0x%x, ax = 0x%x\n", [opcode]:4, ax
+        DEBUGF  DBG_INFO, "opcode = 0x%x, ax = 0x%x\n", [opcode]:4, ax
 
         shr     ax, 8
         and     ax, 0x000F
@@ -483,8 +483,8 @@ proc chip8_emulatecycle stdcall
 
         .sw5_case_A1: ; skip next instruction if key V[X] is NOT pressed
             movzx   ecx, byte [x]
-            movzx   eax, byte [V + ecx]
-            mov     bl, byte [key + eax]
+            movzx   edx, byte [V + ecx]
+            mov     bl, byte [key + edx]
             mov     ax, 4
             cmp     bl, 1
             jne     .sw5_case_A1_endcheck
diff --git a/programs/emulator/chip8/gui.inc b/programs/emulator/chip8/gui.inc
index bc9624b25c..0928768c4f 100644
--- a/programs/emulator/chip8/gui.inc
+++ b/programs/emulator/chip8/gui.inc
@@ -1,17 +1,19 @@
 ; draw main window
 align 4
 proc draw_main_window stdcall
+        DEBUGF  DBG_INFO, "draw_main_window() start\n"
         mcall   12, 1       ; notify about draw beginning
         mcall   48, 3, sys_colors, sizeof.system_colors
         
         mov     edx, [sys_colors.work]         ; background color
         or      edx, 0x74000000                ; window type
         ; DEBUGF  DBG_INFO, "mainwindow w, h  = %u, %u", GFX_COLS*GFX_PIX_SIZE + 8, GFX_ROWS*GFX_PIX_SIZE + 28
-        mcall   0, <50, GFX_COLS*GFX_PIX_SIZE + 8>, <50, GFX_ROWS*GFX_PIX_SIZE + 28>, , , main_window_title ; 
+        mcall   0, <50, GFX_COLS*GFX_PIX_SIZE + 9>, <50, GFX_ROWS*GFX_PIX_SIZE + 28>, , , main_window_title ; 
 
         stdcall draw_screen
 
         mcall   12, 2                  ; notify about draw ending
+        DEBUGF  DBG_INFO, "draw_main_window() end\n"
         ret
 endp