attempt to use both alternate screen buffer sequences.

lib/program.js

@@ -2683,6 +2683,7 @@ Program.prototype.alternateBuffer = function() {
   this.isAlt = true;
   if (this.tput) return this.put.smcup();
   if (this.term('vt') || this.term('linux')) return;
+  this.setMode('?47');
   return this.setMode('?1049');
 };
 
@@ -2791,6 +2792,7 @@ Program.prototype.rmcup =
 Program.prototype.normalBuffer = function() {
   this.isAlt = false;
   if (this.tput) return this.put.rmcup();
+  this.resetMode('?47');
   return this.resetMode('?1049');
 };