implement fast forward

README.md

@@ -66,6 +66,7 @@ Sega gamepad support will be available starting from PCB rev.D (or Rev.C with sl
 | Button | Function |
 | - | - |
 | F1 | Pause |
+| F2 | Fast forward |
 | F5 | Magic button |
 | F10 | Reboot |
 | F12 | Reboot |

cpld/rtl/cpu.sv

@@ -16,6 +16,7 @@ module cpu(
     input [2:0] ram_page128,
     input machine_t machine,
     input turbo_t turbo,
+    input fastforward,
     input hold,
     input ext_wait_cycle1,
     input ext_wait_cycle2,
@@ -90,7 +91,13 @@ localparam INT_L_S128      = 6'd36;
 localparam INT_V_PENT      = 239;
 localparam INT_H_PENT      = 322;
 localparam INT_L_PENT      = 6'd32;
+localparam INT_V_FF1       = 0;
+localparam INT_V_FF2       = 106;
+localparam INT_V_FF3       = 212;
+localparam INT_H_FF        = 0;
 wire int_begin =
+    (fastforward)?
+        (vc == INT_V_FF1 || vc == INT_V_FF2 || vc == INT_V_FF3) && hc == INT_H_FF :
     (machine == MACHINE_S48)?
         vc == INT_V_S48 && hc == INT_H_S48 :
     (machine == MACHINE_S128 || machine == MACHINE_S3)?

cpld/rtl/magic.sv

@@ -14,6 +14,7 @@ module magic(
 
     input magic_button,
     input pause_button,
+    input fastforward_button,
     input div_paged,
     input basic48_paged,
 
@@ -40,7 +41,8 @@ module magic(
     output reg sd_indication_en,
     output reg bright_boost,
     output reg zxkit1,
-    output reg joy_a_up
+    output reg joy_a_up,
+    output reg fastforward
 );
 
 localparam magic_on_start = 1'b1;
@@ -63,7 +65,7 @@ always @(posedge clk28 or negedge rst_n) begin
         opcode_is_reading <= 0;
     end
     else begin
-        if ((magic_button || pause_button) && n_int == 1'b1 && n_int_next == 1'b0) begin
+        if ((magic_button || pause_button || fastforward_button) && n_int == 1'b1 && n_int_next == 1'b0) begin
             if (!magic_mode)
                 n_nmi <= 1'b0;
             magic_mode <= 1'b1;
@@ -136,6 +138,7 @@ always @(posedge clk28 or negedge rst_n) begin
         magic_reboot <= 0;
         magic_beeper <= 0;
         rom_wren <= 0;
+        fastforward <= 0;
     end
     else if (config_cs && bus.wr) case (bus.a[15:8])
         8'h01: {rom_wren, magic_reboot, magic_beeper} <= bus.d[2:0];
@@ -154,11 +157,12 @@ always @(posedge clk28 or negedge rst_n) begin
         8'h0E: autoturbo_en <= bus.d[0];
         8'h0F: zxkit1 <= bus.d[0];
         8'h10: joy_a_up <= bus.d[0];
+        8'h11: fastforward <= bus.d[0];
     endcase
 end
 
 reg config_rd;
-wire [7:0] config_data = {4'b0000, div_paged, 1'b1, pause_button, magic_button};
+wire [7:0] config_data = {4'b0000, div_paged, fastforward_button, pause_button, magic_button};
 always @(posedge clk28 or negedge rst_n) begin
     if (!rst_n)
         config_rd <= 0;
@@ -189,6 +193,8 @@ end
 always @(posedge clk28 or negedge rst_n) begin
     if (!rst_n)
         turbo <= TURBO_NONE;
+    else if (fastforward)
+        turbo <= TURBO_14;
     else if (autoturbo_en && div_paged && !magic_map)
         turbo <= TURBO_14;
     else if (autoturbo_en && |portfe_noturbo)

cpld/rtl/ps2.v

@@ -16,6 +16,7 @@ module ps2#(
     output reg key_magic,
     output reg key_reset,
     output reg key_pause,
+    output reg key_fastforward,
     output reg joy_up,
     output reg joy_down,
     output reg joy_left,
@@ -57,6 +58,7 @@ always @(posedge clk or negedge rst_n) begin
         is_ext <= 0;
         key_magic <= 0;
         key_pause <= 0;
+        key_fastforward <= 0;
         {joy_up, joy_down, joy_left, joy_right, joy_fire} <= 0;
         {key2_a, key2_b, key2_c, key2_d, key2_e, key2_f, key2_g, key2_h, key2_i, key2_j, key2_k, key2_l, key2_m, key2_n} <= 0;
         {key2_o, key2_p, key2_q, key2_r, key2_s, key2_t, key2_u, key2_v, key2_w, key2_x, key2_y, key2_z, key2_0, key2_1} <= 0;
@@ -137,6 +139,7 @@ always @(posedge clk or negedge rst_n) begin
                 `PS2_PGDN:      key2_pgdn <= is_press;
 
                 `PS2_F1:        key_pause <= is_press;
+                `PS2_F2:        key_fastforward <= is_press;
                 `PS2_F5:        key_magic <= is_press;
                 `PS2_F10:       key_reset0 <= is_press;
                 `PS2_F12:       key_reset0 <= is_press;

cpld/rtl/top.sv

@@ -109,6 +109,7 @@ wire joy_a_up;
 wire div_map;
 wire div_mapram;
 wire basic48_paged;
+wire fastforward;
 
 
 /* CPU BUS */
@@ -230,7 +231,7 @@ rgb rgb0(
 
 /* PS/2 KEYBOARD */
 wire [4:0] ps2_kd;
-wire ps2_key_magic;
+wire ps2_key_magic, ps2_key_fastforward;
 wire ps2_joy_up, ps2_joy_down, ps2_joy_left, ps2_joy_right, ps2_joy_fire;
 `ifndef REV_C
 ps2 #(.CLK_FREQ(28_000_000)) ps2_0(
@@ -243,6 +244,7 @@ ps2 #(.CLK_FREQ(28_000_000)) ps2_0(
     .key_magic(ps2_key_magic),
     .key_reset(ps2_key_reset),
     .key_pause(ps2_key_pause),
+    .key_fastforward(ps2_key_fastforward),
     .joy_up(ps2_joy_up),
     .joy_down(ps2_joy_down),
     .joy_left(ps2_joy_left),
@@ -338,6 +340,7 @@ cpu cpu0(
     .machine(machine),
     .video_contention(video_contention),
     .turbo(turbo),
+    .fastforward(fastforward),
     .hold(mem_wait),
     .ext_wait_cycle2(ay_ext_wait_cycle2 | div_ext_wait_cycle2),
 
@@ -389,6 +392,7 @@ magic magic0(
 
     .magic_button(~n_magic || joy_mode || ps2_key_magic),
     .pause_button(ps2_key_pause || joy_start),
+    .fastforward_button(ps2_key_fastforward),
     .div_paged(div_map && !div_mapram),
     .basic48_paged(basic48_paged),
 
@@ -415,7 +419,8 @@ magic magic0(
     .sd_indication_en(sd_indication_en),
     .bright_boost(bright_boost),
     .zxkit1(zxkit1),
-    .joy_a_up(joy_a_up)
+    .joy_a_up(joy_a_up),
+    .fastforward(fastforward)
 );
 
 

rom_src/config.asm

@@ -46,6 +46,7 @@ bright     DB BRIGHT_DEFAULT
 autoturbo  DB 0
 zxkit1     DB 0
 joy_a_up   DB 0
+fastforward DB 0
     ENDS
 
     STRUCT CFGEXT_T

rom_src/main.asm

@@ -56,6 +56,8 @@ startup_handler:
     call detect_external_bdi
     call check_custom_rom
 .warm_boot:
+    xor a
+    ld (cfg_saved.fastforward), a
     call load_config
     call init_cpld
     call save_initialized
@@ -80,15 +82,18 @@ nmi_handler:
     ld (var_magic_enter_cnt), a
     ld (var_magic_leave_cnt), a
 .key_wait_loop:
-    call check_entering_pause ; A[1] == 1 if pause button is pressed
+    xor a                     ;
-    bit 1, a                  ; ...
+    in a, (#ff)               ;
-    jp nz, .enter_pause       ; ...
+    bit 2, a                  ; A[2] == 1 if fastforward button is pressed
+    jr nz, .enter_fastforward ; ...
+    bit 1, a                  ; A[1] == 1 if pause button is pressed
+    jr nz, .enter_pause       ; ...
     call delay_10ms           ;
     call check_entering_menu  ; A == 1 if we are entering menu, A == 2 if we are leaving to...
-    bit 0, a                  ; ...default nmi handler, A == 0 otherwise
+    cp 1                      ; ...default nmi handler, A == 0 otherwise
-    jp nz, .enter_menu        ; ...
+    jr z, .enter_menu         ; ...
-    bit 1, a                  ; ...
+    cp 2                      ; ...
-    jr z, .key_wait_loop      ; ...
+    jr nz, .key_wait_loop     ; ...
 .leave_no_key:
     xor a                     ; disable border
     ld bc, #01ff              ; ...
@@ -96,10 +101,14 @@ nmi_handler:
     ld bc, #00ff              ; ...
     in a, (c)                 ; if divmmc paged - just do retn
     bit 3, a                  ; ...
-    jr nz, exit_with_ret      ; ...
+    jp nz, exit_with_ret      ; ...
     ld hl, #0066              ; otherwise jump to default nmi handler
-    jr exit_with_jp           ; ...
+    jp exit_with_jp           ; ...
 
+.enter_fastforward:
+    ld hl, nmi_fastforward
+    ld (var_main_fun), hl
+    jr .enter
 .enter_pause:
     ld hl, nmi_pause
     ld (var_main_fun), hl
@@ -231,6 +240,8 @@ load_user_config:
 .quirks:                           ; some options shouldn't be saved by user, so we just overwrite them from default config
     ld a, (CFG_DEFAULT.ay)         ; AY should be disabled only by detect_external_ay
     ld (cfg_saved.ay), a           ; ...
+    ld a, (CFG_DEFAULT.fastforward)
+    ld (cfg_saved.fastforward), a
     ret
 
 ; OUT -  A = 1 if error, 0 if ok
@@ -420,13 +431,6 @@ check_custom_rom:
     ret
 
 
-; OUT - A bit 1 if we are entering pause, 0 otherwise
-check_entering_pause:
-    xor a                       ; read pause key state in bit 1 of #00FF port
-    in a, (#ff)                 ; ...
-    ret
-
-
 ; OUT -  A = 1 if we are entering menu, A = 2 if we are leaving menu, A = 0 otherwise
 ; OUT -  F - garbage
 check_entering_menu:
@@ -458,6 +462,10 @@ check_entering_menu:
 ; OUT - AF - garbage
 ; OUT - BC - garbage
 delay_10ms:
+    ld c, 7*4
+    ld a, (cfg.fastforward)
+    or a
+    jr nz, .loop
     ld c, 7
     ld a, (cfg.clock)
     or a
@@ -624,8 +632,18 @@ bootmenu:
     ld hl, menuboot
     call menu_init
     call menu_input_loop
-    call wait_for_keys_release
+    jp wait_for_keys_release
-    ret
+
+
+nmi_fastforward:
+    ld a, (cfg.fastforward)
+    xor 1
+    ld (cfg.fastforward), a
+    ld bc, #11ff
+    out (c), a
+    ei
+    halt
+    jp wait_for_keys_release
 
 
 nmi_pause:
@@ -639,19 +657,7 @@ nmi_pause:
     ld a, (var_exit_flag)
     or a
     jr z, .loop
-.wait_for_pause_key_release:
+    jp wait_for_keys_release
-    xor a              ; read magic/pause keys state from port #00FF
-    in a, (#ff)        ; ...
-    and #03            ; ...
-    jr nz, .wait_for_pause_key_release
-    ei                 ; second read to fix start button bouncing on 8bitdo gamepad
-    halt               ; ...
-.wait_for_pause_key_release2:
-    xor a              ; read magic/pause keys state from port #00FF
-    in a, (#ff)        ; ...
-    and #03            ; ...
-    jr nz, .wait_for_pause_key_release2
-    ret
 
 
 nmi_menu:
@@ -674,8 +680,7 @@ nmi_menu:
     call menu_init
 .loop:
     call menu_input_loop
-    call wait_for_keys_release
+    jp wait_for_keys_release
-    ret
 
 
 menu_input_loop:
@@ -697,6 +702,9 @@ menu_input_loop:
 
 
 wait_for_keys_release:
+    ld b, 2            ; second attempt to fix start button bouncing on 8bitdo gamepad
+.attempt:
+    push bc
 .loop:
     ei
     halt
@@ -704,10 +712,12 @@ wait_for_keys_release:
     xor a
     or b
     jr nz, .loop
-    xor a              ; read magic/pause keys state from port #00FF
+    xor a              ; read magic/pause/fastforward keys state from port #00FF
     in a, (#ff)        ; ...
-    and #03            ; ...
+    and #07            ; ...
     jr nz, .loop
+    pop bc
+    djnz .attempt
     ret