From 2eb1ea08f8279e81a4226367a5fc079addb10897 Mon Sep 17 00:00:00 2001
From: smf- <smf-@users.noreply.github.com>
Date: Sun, 29 Jan 2012 14:24:43 +0000
Subject: [PATCH]  shift in under o2 or t2 control generates clock on cb1.

---
 src/emu/machine/6522via.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/emu/machine/6522via.c b/src/emu/machine/6522via.c
index dcfea35234b..4bb2eae5bad 100644
--- a/src/emu/machine/6522via.c
+++ b/src/emu/machine/6522via.c
@@ -403,6 +403,10 @@ void via6522_device::shift()
 
 	if (SI_O2_CONTROL(m_acr) || SI_T2_CONTROL(m_acr))
 	{
+		/* this should be one cycle wide */
+		m_out_cb1_func(0);
+		m_out_cb1_func(1);
+
 		if (!m_in_cb2_func.isnull())
 		{
 			m_in_cb2 = m_in_cb2_func();