From 636fd9748d3b5ace16a4bb355e397763692ad344 Mon Sep 17 00:00:00 2001
From: SarahW <pcem@pcem-emulator.co.uk>
Date: Sat, 24 Feb 2018 15:09:03 +0000
Subject: [PATCH] Fixed hardcoded memory size on Toshiba T1000/T1200. Added
 ability to disable video on T1200. Patch form John Elliott.

---
 src/t1000.c     | 10 +++++++++-
 src/vid_t1000.c | 14 +++++++++++++-
 src/vid_t1000.h |  1 +
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/t1000.c b/src/t1000.c
index 7dae292..fb5399a 100644
--- a/src/t1000.c
+++ b/src/t1000.c
@@ -210,7 +210,7 @@ static void ems_set_hardram(struct t1000_system *sys, uint8_t val)
 		sys->ems_base = 0;
 	}
 /*	pclog("EMS base set to %02x\n", val); */
-	sys->ems_pages = 48 - 4 * sys->ems_base;
+	sys->ems_pages = ((mem_size - 512) / 16) - 4 * sys->ems_base;
 	if (sys->ems_pages < 0) sys->ems_pages = 0;
 	/* Recalculate EMS mappings */
 	for (n = 0; n < 4; n++)
@@ -421,6 +421,14 @@ static void write_t1000_ctl(uint16_t addr, uint8_t val, void *priv)
 				}
 			}
 			break;
+		/* It looks as if the T1200, like the T3100, can disable
+		 * its builtin video chipset if it detects the presence of
+		 * another video card. */
+		case 6: if (romset == ROM_T1200)
+			{
+				t1000_video_enable(val & 0x01 ? 0 : 1);
+			}
+			break;
 		/* EMS control*/
 		case 0x0F:	
 			switch (sys->sys_ctl[0x0E])
diff --git a/src/vid_t1000.c b/src/vid_t1000.c
index ce9b310..def3eff 100644
--- a/src/vid_t1000.c
+++ b/src/vid_t1000.c
@@ -27,6 +27,7 @@ static uint8_t  language;
  * Bit  0:   Thin font
  */
 static uint8_t st_video_options;
+static uint8_t st_enabled = 1;
 static uint8_t st_display_internal = -1;
 
 void t1000_video_options_set(uint8_t options)
@@ -35,6 +36,11 @@ void t1000_video_options_set(uint8_t options)
 	st_video_options |= language;
 }
 
+void t1000_video_enable(uint8_t enabled)
+{
+	st_enabled = enabled;
+}
+
 void t1000_display_set(uint8_t internal)
 {
 	st_display_internal = internal;
@@ -413,12 +419,18 @@ static void t1000_poll(void *p)
 {
         t1000_t *t1000 = (t1000_t *)p;
 
-	if (t1000->video_options != st_video_options)
+	if (t1000->video_options != st_video_options ||
+	    t1000->enabled != st_enabled)
 	{
 		t1000->video_options = st_video_options;
+		t1000->enabled = st_enabled;
 
 		/* Set the font used for the external display */
 		t1000->cga.fontbase = ((t1000->video_options & 3) * 256);
+
+                if (t1000->enabled) /* Disable internal chipset */
+                        mem_mapping_enable(&t1000->mapping);
+                else    mem_mapping_disable(&t1000->mapping);
 	}
 	/* Switch between internal plasma and external CRT display. */
 	if (st_display_internal != -1 && st_display_internal != t1000->internal)
diff --git a/src/vid_t1000.h b/src/vid_t1000.h
index d85e9c6..f754cfa 100644
--- a/src/vid_t1000.h
+++ b/src/vid_t1000.h
@@ -2,3 +2,4 @@ extern device_t t1000_device;
 
 void t1000_video_options_set(uint8_t options);
 void t1000_display_set(uint8_t internal);
+void t1000_video_enable(uint8_t enabled);