Added IBM Display Adapter II for PS/55 emulation

src/video/CMakeLists.txt

@@ -27,7 +27,7 @@ add_library(vid OBJECT agpgart.c video.c vid_table.c vid_cga.c vid_cga_comp.c
     vid_tkd8001_ramdac.c vid_att20c49x_ramdac.c vid_s3.c vid_s3_virge.c
     vid_ibm_rgb528_ramdac.c vid_sdac_ramdac.c vid_ogc.c vid_mga.c vid_nga.c
     vid_tvp3026_ramdac.c vid_att2xc498_ramdac.c vid_xga.c
-    vid_bochs_vbe.c)
+    vid_bochs_vbe.c vid_ps55da2.c )
 
 if(G100)
     target_compile_definitions(vid PRIVATE USE_G100)

src/video/vid_svga.c

@@ -431,10 +431,24 @@ svga_in(uint16_t addr, void *priv)
             ret = svga->attrregs[svga->attraddr];
             break;
         case 0x3c2:
-            if ((svga->vgapal[0].r + svga->vgapal[0].g + svga->vgapal[0].b) >= 0x4e)
-                ret = 0;
+            if (svga->cable_connected)
+            {
+                if ((svga->vgapal[0].r + svga->vgapal[0].g + svga->vgapal[0].b) >= 0x4e)
+                    ret = 0;
+                else
+                    ret = 0x10;
+            }
             else
-                ret = 0x10;
+            {
+                // The Display Adapter has own Monitor Type Detection bit in the different I/O port (I/O 3E0h, 3E1h).
+                // When the monitor cable is connected to the Display Adapter, this port returns the value as no cable connection.
+                // The Power-on Self Test of PS/55 tries detecting the monitor on the planar VGA.
+                // If it fails, then the POST reads the NVRAM set by the reference diskette, and sets the BIOS Data Area (Mem 487h, 489h).
+                if (svga->vgapal[0].r >= 10 || svga->vgapal[0].g >= 10 || svga->vgapal[0].b >= 10)
+                    ret = 0;
+                else
+                    ret = 0x10;
+            }
             break;
         case 0x3c3:
             ret = vga_on;
@@ -1359,6 +1373,8 @@ svga_init(const device_t *info, svga_t *svga, void *priv, int memsize,
     svga->dac_hwcursor.cur_xsize = svga->dac_hwcursor.cur_ysize = 32;
 
     svga->translate_address         = NULL;
+    
+    svga->cable_connected = 1;
     svga->ksc5601_english_font_type = 0;
 
     vga_on = 1;

src/video/vid_table.c

@@ -367,6 +367,8 @@ video_post_reset(void)
     if (xga_standalone_enabled)
         xga_device_add();
 
+    if (da2_standalone_enabled)
+        da2_device_add();
     /* Reset the graphics card (or do nothing if it was already done
        by the machine's init function). */
     video_reset(gfxcard[0]);

src/video/vid_vga.c

@@ -103,6 +103,39 @@ vga_in(uint16_t addr, void *priv)
     return temp;
 }
 
+void vga_disable(void* p)
+{
+    vga_t* vga = (vga_t*)p;
+    svga_t* svga = &vga->svga;
+
+    pclog("vga_disable %04X:%04X\n", cs >> 4, cpu_state.pc);
+    io_removehandler(0x03a0, 0x0040, vga_in, NULL, NULL, vga_out, NULL, NULL, vga);
+    mem_mapping_disable(&svga->mapping);
+    svga->vga_enabled = 0;
+}
+
+void vga_enable(void* p)
+{
+    vga_t* vga = (vga_t*)p;
+    svga_t* svga = &vga->svga;
+
+    pclog("vga_enable %04X:%04X\n", cs >> 4, cpu_state.pc);
+    io_sethandler(0x03c0, 0x0020, vga_in, NULL, NULL, vga_out, NULL, NULL, vga);
+    if (!(svga->miscout & 1))
+        io_sethandler(0x03a0, 0x0020, vga_in, NULL, NULL, vga_out, NULL, NULL, vga);
+
+    mem_mapping_enable(&svga->mapping);
+    svga->vga_enabled = 1;
+}
+
+int vga_isenabled(void* p)
+{
+    vga_t* vga = (vga_t*)p;
+    svga_t* svga = &vga->svga;
+
+    return svga->vga_enabled;
+}
+
 static void *
 vga_init(const device_t *info)
 {
@@ -149,6 +182,7 @@ ps1vga_init(const device_t *info)
 
     vga->svga.bpp     = 8;
     vga->svga.miscout = 1;
+    vga->svga.vga_enabled = 1;
 
     return vga;
 }