[QL] Added second microdrive support. ROM now selectable.

cores/ql/data_io.v

@@ -83,7 +83,9 @@ always@(posedge sck, posedge ss) begin
 			if(sdi) begin
 				// download rom to address 0, microdrive image to 16MB+
 				if(index == 0) laddr <= 25'h0 - 25'd1;
-				else           laddr <= 25'h800000 - 25'd1;
+				if(index == 1) laddr <= 25'h800000 - 25'd1; //mdv1_
+				if(index == 2) laddr <= 25'h900000 - 25'd1; //mdv2_
+				if(index == 3) laddr <= 25'h0 - 25'd1;  //Additional ROM bios selection
 				
 				downloading_reg <= 1'b1; 
 			end else

cores/ql/mdv.v

@@ -25,8 +25,10 @@ module mdv (
 	input reset,
 	
 	input reverse,
-	
+
-	input sel,
+   input mdv_drive,
+   
+	input sel,               // select microdrive 1 or 2
 
    // control bits	
 	output gap,
@@ -46,8 +48,9 @@ module mdv (
 	input [15:0] mem_din
 );
 
-localparam BASE_ADDR = 25'h800000;   
+// mdv1_ image stored at h800000, mdv2_ image stored at address h900000
-   
+wire [24:0] BASE_ADDR = (mdv_drive == 1)?25'h800000:25'h900000;
+  
 // a gap is permanently present if no mdv is inserted or if
 // there's a gap on the inserted one. This is the signal that triggers
 // the irq and can be seen by the cpu
@@ -118,7 +121,7 @@ always @(posedge mdv_clk) begin
 	mdv_bit_cnt <= mdv_bit_cnt + 4'd1;
 	if(mdv_bit_cnt == 15) begin
 		mdv_data <= mdv_din;
-	        mdv_data_valid <= !mdv_gap_active &&
+	   mdv_data_valid <= !mdv_gap_active &&
 			      // don't generate data_valid for first 12 bytes (preamble)
                               (mdv_gap_cnt > 5) &&
 			      // and also not for the sector internal preamble
@@ -126,8 +129,9 @@ always @(posedge mdv_clk) begin
 	
 		mdv_next_word <= 1'b1;
 
-	        // reset counters when address is out of range
+	   // reset counters when address is out of range
-                if((mem_addr > mdv_end)||(mem_addr < 25'h800000)) begin
+      if((mem_addr > mdv_end)||(mem_addr < BASE_ADDR)) begin
+
 			mem_addr <= BASE_ADDR;
 			
 			// assume we start at the end of a post-sector/pre-header gap

cores/ql/ql.v

@@ -70,7 +70,9 @@ module ql (
 // it to control the menu on the OSD 
 parameter CONF_STR = {
         "QL;;",
-        "F1,MDV;",
+        "F,MDV,Load MDV1;",
+        "F,MDV,Load MDV2;",
+        "F,ROM;",
         "O2,MDV direction,normal,reverse;",
         "O3,RAM,128k,640k;",
         "O4,Video mode,PAL,NTSC;",
@@ -78,7 +80,7 @@ parameter CONF_STR = {
         "T6,Reset"
 };
 
-parameter CONF_STR_LEN = 4+7+32+17+23+20+8;
+parameter CONF_STR_LEN = 4+16+16+6+32+17+23+20+8;
 
 // the status register is controlled by the on screen display (OSD)
 wire [7:0] status;
@@ -206,8 +208,10 @@ wire sys_wr =          dio_download?dio_write:(cpu_wr && cpu_ram);
 wire sys_oe =          dio_download?1'b0:(cpu_rd && cpu_mem);
 
 // microdrive emulation and video share the video cycle time slot
-wire [24:0] video_cycle_addr = mdv_read?mdv_addr:{6'd0, video_addr};
+// only one drive at a time is accessed
-wire video_cycle_rd = mdv_read?1'b1:video_rd;
+wire [24:0] video_cycle_addr = (mdv_read || mdv2_read)?(mdv_seldrive?mdv2_addr:mdv_addr):{6'd0, video_addr};
+wire video_cycle_rd = (mdv_read || mdv2_read)?1'b1:video_rd;
+
 
 // video and CPU/data_io time share the sdram bus
 wire [24:0] sdram_addr = video_cycle?video_cycle_addr:sys_addr;
@@ -352,7 +356,7 @@ osd #(12,0,5) osd (
 // -------------------------------------- reset ------------------------------------
 // ---------------------------------------------------------------------------------
 
-wire rom_download = dio_download && (dio_index == 0);
+wire rom_download = dio_download && (dio_index == 0 || dio_index == 3);
 reg [11:0] reset_cnt;
 wire reset = (reset_cnt != 0);
 always @(posedge clk2) begin
@@ -370,10 +374,15 @@ wire zx8302_sel = cpu_cycle && cpu_io && !cpu_addr[6];
 wire [1:0] zx8302_addr = {cpu_addr[5], cpu_addr[1]};
 wire [15:0] zx8302_dout;
 
-wire mdv_download = (dio_index == 1) && dio_download;
+wire mdv_download = (dio_index == 1) && dio_download;		//signal for active download from SD
-wire mdv_men;
+wire mdv2_download = (dio_index == 2) && dio_download;	//signal for active download from SD
+wire mdv_men;        //signal telling mdv emulation that it may use the video
 wire mdv_read;
+wire mdv2_read;
 wire [24:0] mdv_addr;
+wire [24:0] mdv2_addr;
+wire mdv_seldrive;	//1 for MDV2_ active, 0 for MDV1_ active or nothing
+
 
 wire audio;
 assign AUDIO_L = audio;
@@ -397,7 +406,7 @@ zx8302 zx8302 (
 	.cpu_addr     ( zx8302_addr  ),
 	.cpu_ds       ( cpu_ds       ),
 	.cpu_din      ( cpu_dout     ),
-   .cpu_dout     ( zx8302_dout  ),
+	.cpu_dout     ( zx8302_dout  ),
 
 	// joysticks 
 	.js0          ( js0[4:0]     ),
@@ -410,15 +419,22 @@ zx8302 zx8302 (
 
 	// microdrive sdram interface
 	.mdv_addr     ( mdv_addr     ),
+	.mdv2_addr    ( mdv2_addr    ),
 	.mdv_din      ( sdram_dout   ),
 	.mdv_read     ( mdv_read     ),
+	.mdv2_read    ( mdv2_read    ),
 	.mdv_men      ( mdv_men      ),
 	.video_cycle  ( video_cycle  ),
 	
 	.mdv_reverse  ( status[2]    ),
 
 	.mdv_download ( mdv_download ),
+	.mdv2_download ( mdv2_download ),
+	
+	.mdv_seldrive ( mdv_seldrive) ,
+	
 	.mdv_dl_addr  ( dio_addr     )
+
 );
 	 
 // ---------------------------------------------------------------------------------

cores/ql/zx8302.v

@@ -32,14 +32,19 @@ module zx8302 (
 		
 		// sdram interface for microdrive emulation
 		output [24:0]  mdv_addr,
+		output [24:0]  mdv2_addr,
 		input [15:0]   mdv_din,
 		output         mdv_read,
+		output         mdv2_read,
 		input          mdv_men,
 		input          video_cycle,
 
 		// interface to watch MDV cartridge upload
 		input [24:0]   mdv_dl_addr,
 		input          mdv_download,
+		input          mdv2_download,
+		
+		output 			mdv_seldrive,
 
 		input          mdv_reverse,
 		output         led,
@@ -127,8 +132,10 @@ end
 // bit 7       COMDATA
 
 wire [7:0] io_status = { zx8302_comdata_in, ipc_busy, 2'b00,
-		mdv_gap, mdv_rx_ready, mdv_tx_empty, 1'b0 };
+		(mdv_seldrive?mdv2_gap:mdv_gap), 
-
+		(mdv_seldrive?mdv2_rx_ready:mdv_rx_ready), 
+		(mdv_seldrive?mdv2_tx_empty:mdv_tx_empty), 1'b0 };
+		
 assign cpu_dout =
 	// 18000/18001 and 18002/18003
 	(cpu_addr == 2'b00)?rtc[47:32]:
@@ -136,7 +143,7 @@ assign cpu_dout =
 
 	// 18020/18021 and 18022/18023
 	(cpu_addr == 2'b10)?{io_status, irq_pending}:
-	(cpu_addr == 2'b11)?{mdv_byte, mdv_byte}:
+	(cpu_addr == 2'b11)?(mdv_seldrive?{mdv2_byte, mdv2_byte}:{mdv_byte, mdv_byte}):
 
 	16'h0000;	
 
@@ -213,7 +220,7 @@ always @(posedge vs or posedge vsync_irq_reset) begin
 end
 
 // toggling the mask will also trigger irqs ...
-wire gap_irq_in = mdv_gap && irq_mask[0];
+wire gap_irq_in = (mdv_seldrive?mdv2_gap:mdv_gap) && irq_mask[0];
 reg gap_irq;
 wire gap_irq_reset = reset || irq_ack[0];
 always @(posedge gap_irq_in or posedge gap_irq_reset) begin
@@ -236,16 +243,22 @@ end
 // ---------------------------------------------------------------------------------
 
 wire mdv_gap;
+wire mdv2_gap;
 wire mdv_tx_empty;
+wire mdv2_tx_empty;
 wire mdv_rx_ready;
+wire mdv2_rx_ready;
 wire [7:0] mdv_byte;
+wire [7:0] mdv2_byte;
 
-assign led = !mdv_sel[0];
+assign led = !(mdv_sel[0] || mdv_sel[1]);
 
 mdv mdv (
    .clk      ( clk          ),
 	.reset    ( init         ),
 	
+   .mdv_drive (1),		//This is MDV1_
+   
 	.sel      ( mdv_sel[0]   ),
 
 	.reverse  ( mdv_reverse  ),
@@ -268,12 +281,47 @@ mdv mdv (
 	.mem_din  ( mdv_din      )	
 );
 
+mdv mdv2 (
+   .clk      ( clk          ),
+	.reset    ( init         ),
+   
+   .mdv_drive ( 2 ),		//This is MDV2_
+	
+   .sel      ( mdv_sel[1]   ),
+
+	.reverse  ( mdv_reverse  ),
+
+   // control bits	
+	.gap      ( mdv2_gap      ),
+	.tx_empty ( mdv2_tx_empty ),
+	.rx_ready ( mdv2_rx_ready ),
+	.dout     ( mdv2_byte     ),
+	
+	.download ( mdv2_download ),
+	.dl_addr  ( mdv_dl_addr  ),
+
+	// ram interface to read image
+   .mem_ena  ( mdv_men      ),
+   .mem_cycle( video_cycle  ),
+	.mem_clk  ( clk_bus      ),
+	.mem_addr ( mdv2_addr     ),
+	.mem_read ( mdv2_read     ),  
+
+	.mem_din  ( mdv_din      )	
+);
+
 // the microdrive control register mctrl generates the drive selection
+// mdv_sel = 1 for mdv1_, mdv_sel = 2 for mdv2_
 reg [7:0] mdv_sel;
 
 always @(negedge mctrl[1])
 	mdv_sel <= { mdv_sel[6:0], mctrl[0] };
 
+// 0 for MDV1_ or nothing and 1 for MDV2_
+// Only one microdrive can be accessed at a time, this allows
+// switching between them.
+assign mdv_seldrive = mdv_sel[1]?1'b1:1'b0;
+
 // ---------------------------------------------------------------------------------
 // -------------------------------------- RTC --------------------------------------
 // ---------------------------------------------------------------------------------