diff --git a/src/video/vid_oak_oti.c b/src/video/vid_oak_oti.c
index afacc1150..d2057615d 100644
--- a/src/video/vid_oak_oti.c
+++ b/src/video/vid_oak_oti.c
@@ -29,6 +29,7 @@
 #include <86box/video.h>
 #include <86box/vid_svga.h>
 
+
 #define BIOS_037C_PATH			"roms/video/oti/bios.bin"
 #define BIOS_067_AMA932J_PATH	"roms/machines/ama932j/oti067.bin"
 #define BIOS_067_M300_08_PATH	"roms/machines/olivetti_m300_08/EVC_BIOS.ROM"
@@ -128,7 +129,7 @@ oti_out(uint16_t addr, uint8_t val, void *p)
 		switch (idx) {
 			case 0xD:
 				if (oti->chip_id == OTI_067) {
-					svga->vram_display_mask = (val & 0xc) ? oti->vram_mask : 0x3ffff;
+					svga->vram_display_mask = (val & 0x0c) ? oti->vram_mask : 0x3ffff;
 					if (!(val & 0x80))
 						svga->vram_display_mask = 0x3ffff;
 
@@ -137,24 +138,24 @@ oti_out(uint16_t addr, uint8_t val, void *p)
 					else
 						mem_mapping_enable(&svga->mapping);
 				} else if (oti->chip_id == OTI_077) {
-					svga->vram_display_mask = (val & 0xc) ? oti->vram_mask : 0x3ffff;
+					svga->vram_display_mask = (val & 0x1c) ? oti->vram_mask : 0x3ffff;
 
 					switch ((val & 0xc0) >> 6) {
 						case 0x00:	/* 256 kB of memory */
 						default:
 							enable = (oti->vram_size >= 256);
-							if (val & 0xc)
+							if (val & 0x0c)
 								svga->vram_display_mask = MIN(oti->vram_mask, 0x3ffff);
 							break;
 						case 0x01:	/* 1 MB of memory */
 						case 0x03:
 							enable = (oti->vram_size >= 1024);
-							if (val & 0xc)
+							if (val & 0x0c)
 								svga->vram_display_mask = MIN(oti->vram_mask, 0xfffff);
 							break;
 						case 0x02:	/* 512 kB of memory */
 							enable = (oti->vram_size >= 512);
-							if (val & 0xc)
+							if (val & 0x0c)
 								svga->vram_display_mask = MIN(oti->vram_mask, 0x7ffff);
 							break;
 					}
@@ -329,8 +330,13 @@ oti_recalctimings(svga_t *svga)
     oti_t *oti = (oti_t *)svga->p;
 
     if (oti->regs[0x14] & 0x08) svga->ma_latch |= 0x10000;
+	if (oti->regs[0x16] & 0x08) svga->ma_latch |= 0x20000;
 
-    if (oti->regs[0x0d] & 0x0c) svga->rowoffset <<= 1;
+	if (oti->regs[0x14] & 0x01) svga->vtotal += 0x400;
+	if (oti->regs[0x14] & 0x02) svga->dispend += 0x400;
+	if (oti->regs[0x14] & 0x04) svga->vsyncstart += 0x400;
+
+    if ((oti->regs[0x0d] & 0x0c) && !(oti->regs[0x0d] & 0x10)) svga->rowoffset <<= 1;
 
     svga->interlace = oti->regs[0x14] & 0x80;
 }