diff --git a/src/display.h b/src/display.h
index 525bcd18..46ec20f8 100644
--- a/src/display.h
+++ b/src/display.h
@@ -36,6 +36,17 @@ typedef enum color_mode_t {
     NUM_COLOROPTS
 } color_mode_t;
 
+/*
+ * Font mode
+ */
+typedef enum font_mode_t {
+    FONT_MODE_NORMAL=0,
+    FONT_MODE_MOUSETEXT,
+    FONT_MODE_INVERSE,
+    FONT_MODE_FLASH,
+    NUM_FONT_MODES,
+} font_mode_t;
+
 /*
  * Graphics mode
  */
diff --git a/src/vm.c b/src/vm.c
index e4eb38ea..f1185967 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -804,7 +804,7 @@ GLUE_C_READ(iie_altchar_off)
 {
     if (softswitches & SS_ALTCHAR) {
         softswitches &= ~SS_ALTCHAR;
-        display_loadFont(0x40,0x40,ucase_glyphs,3);
+        display_loadFont(/*start:*/0x40, /*qty:*/0x40, /*data:*/ucase_glyphs, FONT_MODE_FLASH);
         video_setDirty(A2_DIRTY_FLAG);
     }
     return floating_bus();
@@ -814,8 +814,8 @@ GLUE_C_READ(iie_altchar_on)
 {
     if (!(softswitches & SS_ALTCHAR)) {
         softswitches |= SS_ALTCHAR;
-        display_loadFont(0x40,0x20,mousetext_glyphs,1);
-        display_loadFont(0x60,0x20,lcase_glyphs,2);
+        display_loadFont(/*start:*/0x40, /*qty:*/0x20, /*data:*/mousetext_glyphs, FONT_MODE_MOUSETEXT);
+        display_loadFont(/*start:*/0x60, /*qty:*/0x20, /*data:*/lcase_glyphs, FONT_MODE_INVERSE);
         video_setDirty(A2_DIRTY_FLAG);
     }
     return floating_bus();
@@ -970,11 +970,11 @@ static void _initialize_iie_switches(void) {
 }
 
 static void _initialize_font(void) {
-    display_loadFont(0x00,0x40,ucase_glyphs,2);
-    display_loadFont(0x40,0x40,ucase_glyphs,3);
-    display_loadFont(0x80,0x40,ucase_glyphs,0);
-    display_loadFont(0xC0,0x20,ucase_glyphs,0);
-    display_loadFont(0xE0,0x20,lcase_glyphs,0);
+    display_loadFont(/*start:*/0x00, /*qty:*/0x40, /*data:*/ucase_glyphs, FONT_MODE_INVERSE);
+    display_loadFont(/*start:*/0x40, /*qty:*/0x40, /*data:*/ucase_glyphs, FONT_MODE_FLASH);
+    display_loadFont(/*start:*/0x80, /*qty:*/0x40, /*data:*/ucase_glyphs, FONT_MODE_NORMAL);
+    display_loadFont(/*start:*/0xC0, /*qty:*/0x20, /*data:*/ucase_glyphs, FONT_MODE_NORMAL);
+    display_loadFont(/*start:*/0xE0, /*qty:*/0x20, /*data:*/lcase_glyphs, FONT_MODE_NORMAL);
 }
 
 static void _initialize_apple_ii_memory(void) {