diff --git a/src/keyboard_at.c b/src/keyboard_at.c
index ef55fa070..a3260e641 100644
--- a/src/keyboard_at.c
+++ b/src/keyboard_at.c
@@ -8,7 +8,7 @@
  *
  *		Intel 8042 (AT keyboard controller) emulation.
  *
- * Version:	@(#)keyboard_at.c	1.0.13	2018/01/01
+ * Version:	@(#)keyboard_at.c	1.0.14	2018/01/04
  *
  * Authors:	Sarah Walker, <http://pcem-emulator.co.uk/>
  *		Miran Grca, <mgrca8@gmail.com>
@@ -964,12 +964,12 @@ bad_command:
 				kbd->mem[0] |= 0x04;
 				kbd_adddata(0x55);
 				/*Self-test also resets the output port, enabling A20*/
-				if (!(kbd->output_port & 0x02)) {
-					mem_a20_key = 2;
+				if (kbd->output_port & 0x02) {
+					mem_a20_key = 0;
 					mem_a20_recalc();
 					flushmmucache();
 				}
-				kbd->output_port = 0xcf;
+				kbd->output_port = 0xcd;
 				break;
 
 			case 0xab: /*Interface test*/
@@ -1276,7 +1276,7 @@ kbd_reset(void *priv)
     kbd->mem[0] = 0x11;
     kbd->default_mode = 0x02;
     kbd->wantirq = 0;
-    kbd->output_port = 0xcf;
+    kbd->output_port = 0xcd;
     kbd->input_port = (MDA) ? 0xf0 : 0xb0;
     kbd->out_new = -1;
     kbd->last_irq = 0;
diff --git a/src/machine/m_at_opti495.c b/src/machine/m_at_opti495.c
index e629ffb25..caf316aa9 100644
--- a/src/machine/m_at_opti495.c
+++ b/src/machine/m_at_opti495.c
@@ -294,7 +294,8 @@ static void opti495_write(uint16_t addr, uint8_t val, void *p)
                         }
 			if (optireg == 0x27)
 			{
-				mem_a20_key = (val & 0x80) ? 0x00 : 0x02;
+				// mem_a20_alt = (val & 0x80) ? 0x00 : 0x02;
+				mem_a20_alt = (val & 0x80);
 				mem_a20_recalc();
 				flushmmucache();
 			}
diff --git a/src/machine/m_at_wd76c10.c b/src/machine/m_at_wd76c10.c
index 742d63c8c..5e622fb6e 100644
--- a/src/machine/m_at_wd76c10.c
+++ b/src/machine/m_at_wd76c10.c
@@ -6,11 +6,13 @@
 #include <string.h>
 #include <wchar.h>
 #include "../86box.h"
+#include "../device.h"
 #include "../io.h"
 #include "../mem.h"
 #include "../serial.h"
 #include "../floppy/floppy.h"
 #include "../floppy/fdc.h"
+#include "../video/vid_paradise.h"
 #include "machine.h"
 
 
@@ -141,4 +143,6 @@ machine_at_wd76c10_init(machine_t *model)
         machine_at_ide_init(model);
 
         wd76c10_init();
+
+	device_add(&paradise_wd90c11_megapc_device);
 }
diff --git a/src/mem.c b/src/mem.c
index 5e7e8ffcb..64616e964 100644
--- a/src/mem.c
+++ b/src/mem.c
@@ -1358,12 +1358,12 @@ void mem_add_bios()
 }
 
 int mem_a20_key = 0, mem_a20_alt = 0;
-int mem_a20_state = 1;
+int mem_a20_state = 0;
 
 void mem_a20_init(void)
 {
 	if (AT) {
-		rammask = cpu_16bitbus ? 0xffffff : 0xffffffff;
+                rammask = cpu_16bitbus ? 0xefffff : 0xffefffff;
 		flushmmucache();
         	mem_a20_state = mem_a20_key | mem_a20_alt;
 	} else {
@@ -1461,8 +1461,6 @@ void mem_init(void)
 	mem_mapping_add(&ram_split_mapping,  mem_size * 1024, 384 * 1024, mem_read_ram,    mem_read_ramw,    mem_read_raml,    mem_write_ram, mem_write_ramw, mem_write_raml,   ram + (1 << 20),  MEM_MAPPING_INTERNAL, NULL);
 	mem_mapping_disable(&ram_split_mapping);
 
-        mem_a20_key = 2;
-	mem_a20_alt = 0;
         mem_a20_init();
 }
 
@@ -1635,8 +1633,6 @@ void mem_resize()
 	mem_mapping_add(&ram_split_mapping,  mem_size * 1024, 384 * 1024, mem_read_ram,    mem_read_ramw,    mem_read_raml,    mem_write_ram, mem_write_ramw, mem_write_raml,   ram + (1 << 20),  MEM_MAPPING_INTERNAL, NULL);
 	mem_mapping_disable(&ram_split_mapping);
 
-        mem_a20_key = 2;
-	mem_a20_alt = 0;
         mem_a20_init();
 }
 
@@ -1691,7 +1687,7 @@ static void port_92_write(uint16_t port, uint8_t val, void *priv)
 {
 	if ((mem_a20_alt ^ val) & 2)
 	{
-		mem_a20_alt = val & 2;
+		mem_a20_alt = (val & 2) ? 0 : 2;
 		mem_a20_recalc();
 	}