From d3679a6ff400baed54ee6ae786132938c14f5b44 Mon Sep 17 00:00:00 2001
From: arbee <rb6502@users.noreply.github.com>
Date: Sun, 24 Jun 2018 19:53:10 -0400
Subject: [PATCH] sonydriv: fixed long-standing disk-switch regression [R.
 Belmont]

---
 src/devices/machine/sonydriv.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/devices/machine/sonydriv.cpp b/src/devices/machine/sonydriv.cpp
index b64743afb0d..c18b6429ae0 100644
--- a/src/devices/machine/sonydriv.cpp
+++ b/src/devices/machine/sonydriv.cpp
@@ -430,6 +430,12 @@ static void sony_doaction(device_t *device)
 			break;
 		case 0x03:  /* Reset diskswitched */
 			f->disk_switched = 0;
+			// flopdrv.cpp won't reset its disk switch flag without
+			// doing a seek.  So we do a seek of 0 tracks, which works.
+			if (cur_image)
+			{
+				cur_image->floppy_drive_seek(0);
+			}
 			break;
 		case 0x04:  /* Step disk */
 			if (cur_image)