Restructuring of the OSD menu

Model selection is now allowed, between IBM PCXT and Tandy 1000, video selection reverts to CGA/Tandy or MDA.

The Tandy 1000 model would be intended for BIOSes of this type, and the IBM PCXT model, the same.

PCXT.sv

@@ -206,20 +206,21 @@ assign VIDEO_ARY = (!ar) ? 12'd3 : 12'd0;
 localparam CONF_STR = {
 	"PCXT;;",
 	"-;",
-	"O7,Splash Screen,Yes,No;",
-	//"O4,CPU Speed,4.77Mhz,7.16Mhz;",	
+	"O3,Model,IBM PCXT,Tandy 1000;",
 	"-;",
 	"OA,Adlib,On,Invisible;",
-	"-;",
+	//"O4,CPU Speed,4.77Mhz,7.16Mhz;",	
 	"OB,Lo-tech 2MB EMS, Enabled, Disabled;",
 	"OCD,EMS Frame,A000,C000,D000;",
 	"-;",
-	"O34,Video Output,CGA,Tandy,MDA;",
+	"O4,Video Output,CGA/Tandy,MDA;",
 	"O12,CGA/Tandy RGB,Color,Green,Amber,B/W;",
 	"O56,MDA RGB,Green,Amber,B/W;",
 	"O89,Aspect ratio,Original,Full Screen,[ARC1],[ARC2];",	
 	//"O78,Scandoubler Fx,None,HQ2x,CRT 25%,CRT 50%;",	
 	"-;",
+	"O7,Splash Screen,Yes,No;",	
+	"-;",
 	"F1,ROM,Load BIOS  (F000);",	
 	"F2,ROM,Load XTIDE (EC00);",	
 	"-;",
@@ -553,11 +554,8 @@ end
     logic   [7:0]   port_c_in;	 
 	 reg     [7:0]   sw;
 
-	 wire tandy_mode;
-	 wire mda_mode;
-	 assign tandy_mode = (status[4:3] == 1);
-	 assign mda_mode = (status[4:3] == 2);
-
+	 wire tandy_mode = status[3];
+	 wire mda_mode = status[4];	 
 
 
 	 assign  sw = mda_mode ? 8'b00111101 : 8'b00101101; // PCXT DIP Switches (MDA or CGA 80)

rtl/video/cga.v

@@ -119,7 +119,7 @@ module cga(
 
 	 assign de_o = display_enable;
 
-	 assign ram_a = {4'b0001, pixel_addr14, pixel_addr13, crtc_addr[11:0],
+	 assign ram_a = {4'h0, pixel_addr14, pixel_addr13, crtc_addr[11:0],
                     vram_read_a0};
 
 	 assign ram_1_d = ram_d;

rtl/video/cga_pixel.sv

@@ -199,7 +199,7 @@ module cga_pixel(
         .c0(pix_bits[0]),
         .c1(pix_bits[1]),
         .pix_640(pix_640),
-        .pix_tandy(tandy_bits), // tandy_palette[tandy_bits]
+        .pix_tandy(tandy_bits),
         .pix_out(video_out)
     );