diff --git a/src/mame/drivers/thayers.cpp b/src/mame/drivers/thayers.cpp
index ffc4e397e59..ca0cd4c1bf3 100644
--- a/src/mame/drivers/thayers.cpp
+++ b/src/mame/drivers/thayers.cpp
@@ -321,7 +321,9 @@ WRITE_LINE_MEMBER(thayers_state::kbclk_w)
 	if (!m_kbclk && state) {
 		m_rx_bit++;
 
-		if (m_rx_bit == 10) {
+		switch (m_rx_bit)
+		{
+		case 10:
 			m_rx_bit = 0;
 
 			m_keylatch++;
@@ -331,18 +333,20 @@ WRITE_LINE_MEMBER(thayers_state::kbclk_w)
 			}
 
 			if (LOG) logerror("keylatch %u\n",m_keylatch);
-		}
+			break;
 
-		if (LOG) logerror("rx bit %u\n",m_rx_bit);
+		case 9:
+			// 1, 0, 1, Q9, P3, P2, P1, P0, 0, 1
+			m_keydata = 0xa0 | (m_keylatch == 9) << 4 | m_row[m_keylatch]->read();
 
-		if (BIT(m_rx_bit, 3)) {
-			// 1, 0, 1, Q9, P3, P2, P1, P0, 1, 1
-			bool q9 = (m_keylatch == 9);
-			m_keydata = 0xa0 | q9 << 4 | m_row[m_keylatch]->read();
 			if (LOG) logerror("keydata %02x keylatch %u\n",m_keydata,m_keylatch);
-		} else if (m_rx_bit) {
+			break;
+
+		default:
 			m_keydata <<= 1;
+
 			if (LOG) logerror("keydata %02x shift\n",m_keydata);
+			break;
 		}
 	}