From b4bea10c0638a0ccdd31dcdd49247f8a1e1ea2d8 Mon Sep 17 00:00:00 2001
From: TomW <TomW@localhost>
Date: Sat, 29 Mar 2014 15:17:23 +0000
Subject: [PATCH] Set transmitter shift register empty bit in serial LSR.
 Windows 3.1 no longer hangs when DOS mouse driver loaded.

---
 src/serial.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/serial.c b/src/serial.c
index f5088a8..bd9a1e5 100644
--- a/src/serial.c
+++ b/src/serial.c
@@ -172,7 +172,10 @@ uint8_t serial_read(uint16_t addr, void *p)
         {
                 case 0:
                 if (serial->lcr & 0x80 && !AMSTRADIO)
-                        return serial->dlab1;
+                {
+                        temp = serial->dlab1;
+                        break;
+                }
 
                 serial->lsr &= ~1;
                 serial->int_status &= ~SERIAL_INT_RECEIVE;
@@ -206,6 +209,8 @@ uint8_t serial_read(uint16_t addr, void *p)
                 temp = serial->mctrl;
                 break;
                 case 5:
+                if (serial->lsr & 0x20)
+                        serial->lsr |= 0x40;
                 serial->lsr |= 0x20;
                 temp = serial->lsr;
                 if (serial->lsr & 0x1f)