--- file_not_specified_in_diff	
+++ file_not_specified_in_diff	
@@ -, +, @@ 
--- mupdf-0.8.165/apps/man/mupdf.1
+++ mupdf-0.8.165/apps/man/mupdf.1
@@ -37,6 +37,15 @@ 
 .B \+, \-
 Zoom in or out.
 .TP
+.B _
+Reset zoom to default (72dpi).
+.TP
+.B z
+Zoom page size to fit into the window frame.
+.TP
+.B Z
+Zoom page size to fill the window frame.
+.TP
 .B w
 Shrinkwrap window to fit the page.
 .TP
--- mupdf-0.8.165/apps/pdfapp.c
+++ mupdf-0.8.165/apps/pdfapp.c
@@ -736,6 +736,20 @@ 
 		pdfapp_showpage(app, 0, 1, 1);
 		break;
 
+	case '_': // zoom to default resolution
+		app->resolution = 72;
+		pdfapp_showpage(app, 0, 1, 1);
+		break;
+
+	case 'z': // zoom to fit window
+	case 'Z': // zoom to fill window
+		if ( ( c == 'Z' ) ^ ( app->image->w * app->winh > app->winw * app->image->h ) ) 
+			app->resolution = ( app->resolution * app->winw ) / app->image->w;
+		else
+			app->resolution = ( app->resolution * app->winh ) / app->image->h;
+		pdfapp_showpage(app, 0, 1, 1);
+		break; 
+
 	case 'L':
 		app->rotate -= 90;
 		pdfapp_showpage(app, 0, 1, 1);
@@ -859,6 +873,7 @@ 
 		break;
 
 	case 'b':
+	case '\b': //backspace
 		panto = DONT_PAN;
 		if (app->numberlen > 0)
 			app->pageno -= atoi(app->number);
@@ -867,6 +882,7 @@ 
 		break;
 
 	case ' ':
+	case 'F':
 		panto = DONT_PAN;
 		if (app->numberlen > 0)
 			app->pageno += atoi(app->number);