-- Ultimate SD Cartridge - Atari 400/800/XL/XE Multi-Cartridge -- Copyright (C) 2015 Robin Edwards -- -- This program is free software; you can redistribute it and/or -- modify it under the terms of the GNU General Public License -- as published by the Free Software Foundation; either version 2 -- of the License, or (at your option) any later version. -- -- This program is distributed in the hope that it will be useful, -- but WITHOUT ANY WARRANTY; without even the implied warranty of -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -- GNU General Public License for more details. -- -- You should have received a copy of the GNU General Public License -- along with this program; if not, write to the Free Software -- Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. LIBRARY ieee; USE ieee.std_logic_1164.all; USE ieee.numeric_std.all; ENTITY atari_rom IS PORT ( CLK: in std_logic; LED: out std_logic_vector(4 downto 0); CART_ADDR: in std_logic_vector(12 downto 0); CART_DATA: inout std_logic_vector(7 downto 0); CART_RD5: out std_logic; CART_RD4: out std_logic; CART_S5: in std_logic; CART_S4: in std_logic; CART_PHI2: in std_logic; CART_CTL: in std_logic; CART_RW: in std_logic; SD_CARD_cs: out std_logic; SD_CARD_sclk: out std_logic; SD_CARD_mosi: out std_logic; SD_CARD_miso: in std_logic; EXT_SRAM_ADDR: out std_logic_vector(19 downto 0); EXT_SRAM_DATA: inout std_logic_vector(7 downto 0); EXT_SRAM_CE: out std_logic; EXT_SRAM_OE: out std_logic; EXT_SRAM_WE: out std_logic ); END atari_rom; ARCHITECTURE structure OF atari_rom IS constant CART_TYPE_BOOT : integer := 0; constant CART_TYPE_8K : integer := 1; constant CART_TYPE_16K : integer := 2; constant CART_TYPE_ATARIMAX_1MBIT : integer := 3; constant CART_TYPE_ATARIMAX_8MBIT : integer := 4; constant CART_TYPE_XEGS_32K : integer := 5; constant CART_TYPE_XEGS_64K : integer := 6; constant CART_TYPE_XEGS_128K : integer := 7; constant CART_TYPE_XEGS_256K : integer := 8; constant CART_TYPE_XEGS_512K : integer := 9; constant CART_TYPE_XEGS_1024K : integer := 10; constant CART_TYPE_SW_XEGS_32K : integer := 11; constant CART_TYPE_SW_XEGS_64K : integer := 12; constant CART_TYPE_SW_XEGS_128K : integer := 13; constant CART_TYPE_SW_XEGS_256K : integer := 14; constant CART_TYPE_SW_XEGS_512K : integer := 15; constant CART_TYPE_SW_XEGS_1024K : integer := 16; constant CART_TYPE_MEGACART_16K : integer := 17; constant CART_TYPE_MEGACART_32K : integer := 18; constant CART_TYPE_MEGACART_64K : integer := 19; constant CART_TYPE_MEGACART_128K : integer := 20; constant CART_TYPE_MEGACART_256K : integer := 21; constant CART_TYPE_MEGACART_512K : integer := 22; constant CART_TYPE_MEGACART_1024K : integer := 23; constant CART_TYPE_BOUNTY_BOB : integer := 24; constant CART_TYPE_WILLIAMS_64K : integer := 25; constant CART_TYPE_OSS_16K_034M : integer := 26; constant CART_TYPE_OSS_16K_043M : integer := 27; constant CART_TYPE_OSS_16K_TYPE_B : integer := 28; constant CART_TYPE_OSS_8K : integer := 29; constant CART_TYPE_SIC : integer := 30; constant CART_TYPE_SDX_64K : integer := 31; constant CART_TYPE_DIAMOND_64K : integer := 32; constant CART_TYPE_EXPRESS_64K : integer := 33; constant CART_TYPE_SDX_128K : integer := 34; constant CART_TYPE_BLIZZARD_16K : integer := 35; constant CART_TYPE_TURBOSOFT : integer := 36; constant CART_TYPE_ATRAX_128K : integer := 37; constant CART_TYPE_4K : integer := 38; constant CART_TYPE_ATARIMAX_8MBIT_NEW : integer := 39; constant CART_TYPE_JACART_8 : integer := 40; constant CART_TYPE_JACART_16 : integer := 41; constant CART_TYPE_JACART_32 : integer := 42; constant CART_TYPE_JACART_64 : integer := 43; constant CART_TYPE_JACART_128 : integer := 44; constant CART_TYPE_JACART_256 : integer := 45; constant CART_TYPE_JACART_512 : integer := 46; constant CART_TYPE_JACART_1024 : integer := 47; constant CART_TYPE_DCART : integer := 48; constant CART_TYPE_XEX : integer := 254; constant CART_TYPE_NONE : integer := 255; signal fpga_data_out : std_logic_vector (7 downto 0); signal sram_data_out : std_logic_vector (7 downto 0); signal data_out : std_logic_vector (7 downto 0); signal fpga_address_in : std_logic_vector (12 downto 0); signal sram_address_in : std_logic_vector (19 downto 0); signal cart_type_in: std_logic_vector (7 downto 0); signal cart_type: integer range 0 to 255 := CART_TYPE_BOOT; signal sram_cart_bus_enabled: std_logic; signal sram_ce: std_logic; signal nios_led_out: std_logic_vector(4 downto 0); -- High (0xA000) / Low (0x8000) cartridge bank enable flags signal high_bank_enabled: std_logic := '1'; signal low_bank_enabled: std_logic := '0'; signal bank_out: std_logic_vector (6 downto 0); -- Used for sending data from atari to FPGA/NIOS cpu signal atari_d500_byte: std_logic_vector(7 downto 0) := "00000000"; signal reset_d500_byte: std_logic; -- Bounty bob cartridge selected 4k banks signal bounty_bob_bank8 : std_logic_vector (1 downto 0); signal bounty_bob_bank9 : std_logic_vector (1 downto 0); -- OSS 4k banks signal oss_bank : std_logic_vector (1 downto 0); -- SIC d500 byte signal sic_d500_byte : std_logic_vector(7 downto 0); signal sic_read_d500 : boolean := false; -- XEX access signal file_offset: std_logic_vector(15 downto 0); signal xex_read_d500 : boolean := false; signal xex_access: std_logic; -- Register some cartridge bus signals on the rising edge signal cart_addr_reg : std_logic_vector (12 downto 0); signal cart_ctl_reg : std_logic := '1'; signal cart_s4_reg : std_logic := '1'; signal cart_s5_reg : std_logic := '1'; signal cart_rw_reg : std_logic := '1'; component host is port ( cart_memory_s2_address : in std_logic_vector(12 downto 0) := (others => 'X'); -- address cart_memory_s2_chipselect : in std_logic := 'X'; -- chipselect cart_memory_s2_clken : in std_logic := 'X'; -- clken cart_memory_s2_write : in std_logic := 'X'; -- write cart_memory_s2_readdata : out std_logic_vector(7 downto 0); -- readdata cart_memory_s2_writedata : in std_logic_vector(7 downto 0) := (others => 'X'); -- writedata clk_clk : in std_logic := 'X'; -- clk ext_sram_atari_bus_driven_export : in std_logic := 'X'; -- atari_bus_driven_export ext_sram_atari_sram_addr_export : in std_logic_vector(19 downto 0) := (others => 'X'); -- atari_sram_addr_export ext_sram_atari_sram_data_export : out std_logic_vector(7 downto 0); -- atari_sram_data_export ext_sram_atari_sram_enable_export : in std_logic := 'X'; -- atari_sram_enable_export ext_sram_sram_addr_export : out std_logic_vector(19 downto 0); -- sram_addr_export ext_sram_sram_dq_export : inout std_logic_vector(7 downto 0) := (others => 'X'); -- sram_dq_export ext_sram_sram_ce_export : out std_logic; -- sram_ce_export ext_sram_sram_oe_n_export : out std_logic; -- sram_oe_n_export ext_sram_sram_we_n_export : out std_logic; -- sram_we_n_export led_external_connection_export : out std_logic_vector(4 downto 0); -- export sel_cartridge_type_export : out std_logic_vector(7 downto 0); -- export reset_reset_n : in std_logic := 'X'; -- reset_n spi_master_0_cs : out std_logic; -- cs spi_master_0_sclk : out std_logic; -- sclk spi_master_0_mosi : out std_logic; -- mosi spi_master_0_miso : in std_logic := 'X'; -- miso spi_master_0_cd : in std_logic := 'X'; -- cd spi_master_0_wp : in std_logic := 'X'; -- wp atari_d500_byte_export : in std_logic_vector(7 downto 0) := (others => 'X'); -- export reset_d500_export : out std_logic -- export ); end component host; BEGIN u0 : component host port map ( clk_clk => CLK, led_external_connection_export => nios_led_out, reset_reset_n => '1', cart_memory_s2_address => fpga_address_in, cart_memory_s2_chipselect => '1', cart_memory_s2_clken => '1', cart_memory_s2_write => '0', cart_memory_s2_readdata => fpga_data_out, cart_memory_s2_writedata => "ZZZZZZZZ", ext_sram_sram_addr_export => EXT_SRAM_ADDR, ext_sram_sram_ce_export => EXT_SRAM_CE, ext_sram_sram_oe_n_export => EXT_SRAM_OE, ext_sram_sram_we_n_export => EXT_SRAM_WE, ext_sram_sram_dq_export => EXT_SRAM_DATA, ext_sram_atari_bus_driven_export => sram_cart_bus_enabled, ext_sram_atari_sram_addr_export => sram_address_in, ext_sram_atari_sram_data_export => sram_data_out, ext_sram_atari_sram_enable_export => sram_ce, sel_cartridge_type_export => cart_type_in, spi_master_0_cs => SD_CARD_cs, spi_master_0_sclk => SD_CARD_sclk, spi_master_0_mosi => SD_CARD_mosi, spi_master_0_miso => SD_CARD_miso, spi_master_0_cd => '0', spi_master_0_wp => '0', atari_d500_byte_export => atari_d500_byte, reset_d500_export => reset_d500_byte ); CART_RD5 <= high_bank_enabled; CART_RD4 <= low_bank_enabled; CART_DATA <= data_out when ((CART_S5 = '0' and high_bank_enabled = '1') or (CART_S4 = '0' and low_bank_enabled = '1') or (CART_CTL = '0' and (sic_read_d500 or xex_read_d500))) else "ZZZZZZZZ"; sram_cart_bus_enabled <= '0' when cart_type = CART_TYPE_BOOT else '1'; xex_access <= '1' when xex_read_d500 else '0'; LED <= nios_led_out when cart_type = CART_TYPE_BOOT else "0000" & not (high_bank_enabled or low_bank_enabled or xex_access); -- store the cartridge bus address on rising edge of phi2 -- since it may be invalid by the falling edge (outside spec 6502s) process (CART_PHI2) begin if (rising_edge(CART_PHI2)) then cart_addr_reg <= CART_ADDR; cart_ctl_reg <= CART_CTL; cart_s4_reg <= CART_S4; cart_s5_reg <= CART_S5; cart_rw_reg <= CART_RW; -- SIC D500-D51F read ? sic_read_d500 <= (cart_type = CART_TYPE_SIC and CART_CTL = '0' and CART_RW = '1' and CART_ADDR(7 downto 5) = "000"); -- XEX D500-D5FF read ? xex_read_d500 <= (cart_type = CART_TYPE_XEX and CART_CTL = '0' and CART_RW = '1'); end if; end process; process (CART_PHI2, reset_d500_byte) variable new_cart_type : integer; begin if (reset_d500_byte = '1') then atari_d500_byte <= "00000000"; else if (falling_edge(CART_PHI2)) then -- uses _reg signals (captured on rising edge) in place of actual cartridge signals (except data bus) -- Change of cartridge type? if (cart_type /= to_integer(unsigned(cart_type_in))) then new_cart_type := to_integer(unsigned(cart_type_in)); -- Default to high bank only low_bank_enabled <= '0'; high_bank_enabled <= '1'; bank_out <= "0000000"; -- Cartridge type specific initialisation if (new_cart_type = CART_TYPE_NONE or new_cart_type = CART_TYPE_XEX) then high_bank_enabled <= '0'; file_offset <= (others => '0'); elsif (new_cart_type = CART_TYPE_16K or new_cart_type = CART_TYPE_BLIZZARD_16K) then low_bank_enabled <= '1'; elsif (new_cart_type = CART_TYPE_ATARIMAX_8MBIT) then bank_out <= "1111111"; elsif (new_cart_type >= CART_TYPE_XEGS_32K and new_cart_type <= CART_TYPE_XEGS_1024K) then low_bank_enabled <= '1'; elsif (new_cart_type >= CART_TYPE_SW_XEGS_32K and new_cart_type <= CART_TYPE_SW_XEGS_1024K) then low_bank_enabled <= '1'; elsif (new_cart_type >= CART_TYPE_MEGACART_16K and new_cart_type <= CART_TYPE_MEGACART_1024K) then low_bank_enabled <= '1'; elsif (new_cart_type = CART_TYPE_BOUNTY_BOB) then low_bank_enabled <= '1'; bounty_bob_bank8 <= "00"; bounty_bob_bank9 <= "00"; elsif (new_cart_type = CART_TYPE_OSS_16K_TYPE_B or new_cart_type = CART_TYPE_OSS_8K) then oss_bank <= "01"; elsif (new_cart_type = CART_TYPE_OSS_16K_034M or new_cart_type = CART_TYPE_OSS_16K_043M) then oss_bank <= "00"; elsif (new_cart_type = CART_TYPE_SIC) then low_bank_enabled <= '1'; sic_d500_byte <= (others => '0'); end if; cart_type <= new_cart_type; end if; -- CCTL set? if (cart_ctl_reg = '0') then case cart_type is -- boot ROM when CART_TYPE_BOOT => if (cart_addr_reg(7 downto 0) = x"10") then -- restrict to D510 only for compatability with Ultimate 1meg atari_d500_byte <= CART_DATA; end if; -- atarimax 1mbit bankswitching when CART_TYPE_ATARIMAX_1MBIT => if (cart_addr_reg(7 downto 5) = "000") then high_bank_enabled <= not cart_addr_reg(4); bank_out <= "000" & cart_addr_reg(3 downto 0); end if; -- atarimax 8mbit bankswitching when CART_TYPE_ATARIMAX_8MBIT | CART_TYPE_ATARIMAX_8MBIT_NEW => high_bank_enabled <= not cart_addr_reg(7); bank_out <= cart_addr_reg(6 downto 0); -- xegs carts - schematic has RW as NC when CART_TYPE_XEGS_32K => bank_out <= "00000" & CART_DATA(1 downto 0); when CART_TYPE_XEGS_64K => bank_out <= "0000" & CART_DATA(2 downto 0); when CART_TYPE_XEGS_128K => bank_out <= "000" & CART_DATA(3 downto 0); when CART_TYPE_XEGS_256K => bank_out <= "00" & CART_DATA(4 downto 0); when CART_TYPE_XEGS_512K => bank_out <= "0" & CART_DATA(5 downto 0); when CART_TYPE_XEGS_1024K => bank_out <= CART_DATA(6 downto 0); -- williams when CART_TYPE_WILLIAMS_64K => if (cart_addr_reg(7 downto 4) = "0000") then high_bank_enabled <= not cart_addr_reg(3); bank_out <= "0000" & cart_addr_reg(2 downto 0); end if; -- oss type b 16k/8k when CART_TYPE_OSS_16K_TYPE_B | CART_TYPE_OSS_8K => high_bank_enabled <= not (cart_addr_reg(3) and not cart_addr(0)); if (cart_addr_reg(0) = '0' and cart_addr_reg(3) = '0') then oss_bank <= "01"; elsif (cart_addr_reg(0) = '1' and cart_addr_reg(3) = '1') then oss_bank <= "10"; elsif (cart_addr_reg(0) = '1' and cart_addr_reg(3) = '0') then oss_bank <= "11"; end if; -- oss 043M when CART_TYPE_OSS_16K_043M => high_bank_enabled <= not cart_addr_reg(3); case cart_addr_reg(2 downto 0) is when "000" => oss_bank <= "00"; when "011" | "111" => oss_bank <= "10"; when "100" => oss_bank <= "01"; when others => null; end case; -- oss 043M when CART_TYPE_OSS_16K_034M => high_bank_enabled <= not cart_addr_reg(3); case cart_addr_reg(2 downto 0) is when "000" => oss_bank <= "00"; when "011" | "111" => oss_bank <= "01"; when "100" => oss_bank <= "10"; when others => null; end case; -- sdx 64 when CART_TYPE_SDX_64K => if (cart_addr_reg(7 downto 4) = x"E") then high_bank_enabled <= not cart_addr_reg(3); bank_out <= "0000" & not cart_addr_reg(2 downto 0); end if; when CART_TYPE_DIAMOND_64K => if (cart_addr_reg(7 downto 4) = x"D") then high_bank_enabled <= not cart_addr_reg(3); bank_out <= "0000" & not cart_addr_reg(2 downto 0); end if; when CART_TYPE_EXPRESS_64K => if (cart_addr_reg(7 downto 4) = x"7") then high_bank_enabled <= not cart_addr_reg(3); bank_out <= "0000" & not cart_addr_reg(2 downto 0); end if; when CART_TYPE_SDX_128K => if (cart_addr_reg(7 downto 4) = x"F") then high_bank_enabled <= not cart_addr_reg(3); bank_out <= "0000" & not cart_addr_reg(2 downto 0); end if; if (cart_addr_reg(7 downto 4) = x"E") then high_bank_enabled <= not cart_addr_reg(3); bank_out <= "0001" & not cart_addr_reg(2 downto 0); end if; when CART_TYPE_BLIZZARD_16K => high_bank_enabled <= '0'; low_bank_enabled <= '0'; -- TurboSoft 64k & 128k when CART_TYPE_TURBOSOFT => if (cart_addr_reg(7 downto 5) = "000") then high_bank_enabled <= not cart_addr_reg(4); bank_out <= "000" & cart_addr_reg(3 downto 0); end if; -- Atrax 128K when CART_TYPE_ATRAX_128K => high_bank_enabled <= not CART_DATA(7); bank_out <= "000" & CART_DATA(3 downto 0); -- jataricart when CART_TYPE_JACART_8 => high_bank_enabled <= not cart_addr_reg(7); bank_out <= "0000000"; when CART_TYPE_JACART_16 => high_bank_enabled <= not cart_addr_reg(7); bank_out <= "000000" & cart_addr_reg(0); when CART_TYPE_JACART_32 => high_bank_enabled <= not cart_addr_reg(7); bank_out <= "00000" & cart_addr_reg(1 downto 0); when CART_TYPE_JACART_64 => high_bank_enabled <= not cart_addr_reg(7); bank_out <= "0000" & cart_addr_reg(2 downto 0); when CART_TYPE_JACART_128 => high_bank_enabled <= not cart_addr_reg(7); bank_out <= "000" & cart_addr_reg(3 downto 0); when CART_TYPE_JACART_256 => high_bank_enabled <= not cart_addr_reg(7); bank_out <= "00" & cart_addr_reg(4 downto 0); when CART_TYPE_JACART_512 => high_bank_enabled <= not cart_addr_reg(7); bank_out <= "0" & cart_addr_reg(5 downto 0); when CART_TYPE_JACART_1024 => high_bank_enabled <= not cart_addr_reg(7); bank_out <= cart_addr_reg(6 downto 0); -- dcart 512k when CART_TYPE_DCART => high_bank_enabled <= not cart_addr_reg(7); bank_out <= "0" & cart_addr_reg(5 downto 0); when others => null; end case; -- carts that require a data write if (cart_rw_reg = '0') then case cart_type is -- switchable xegs when CART_TYPE_SW_XEGS_32K => bank_out <= "00000" & CART_DATA(1 downto 0); when CART_TYPE_SW_XEGS_64K => bank_out <= "0000" & CART_DATA(2 downto 0); when CART_TYPE_SW_XEGS_128K => bank_out <= "000" & CART_DATA(3 downto 0); when CART_TYPE_SW_XEGS_256K => bank_out <= "00" & CART_DATA(4 downto 0); when CART_TYPE_SW_XEGS_512K => bank_out <= "0" & CART_DATA(5 downto 0); when CART_TYPE_SW_XEGS_1024K => bank_out <= CART_DATA(6 downto 0); -- megacart when CART_TYPE_MEGACART_32K => bank_out <= "000000" & CART_DATA(0); when CART_TYPE_MEGACART_64K => bank_out <= "00000" & CART_DATA(1 downto 0); when CART_TYPE_MEGACART_128K => bank_out <= "0000" & CART_DATA(2 downto 0); when CART_TYPE_MEGACART_256K => bank_out <= "000" & CART_DATA(3 downto 0); when CART_TYPE_MEGACART_512K => bank_out <= "00" & CART_DATA(4 downto 0); when CART_TYPE_MEGACART_1024K => bank_out <= "0" & CART_DATA(5 downto 0); -- sic (all sizes) when CART_TYPE_SIC => if (cart_addr_reg(7 downto 5) = "000") then high_bank_enabled <= not CART_DATA(6); low_bank_enabled <= CART_DATA(5); bank_out <= "00" & CART_DATA(4 downto 0); sic_d500_byte <= CART_DATA; end if; -- xex loader support - D500,D501 are lo-byte hi-byte of file offset (in 256 byte chunks) when CART_TYPE_XEX => if (cart_addr_reg(7 downto 0) = x"00") then file_offset(7 downto 0) <= CART_DATA; elsif (cart_addr_reg(7 downto 0) = x"01") then file_offset(15 downto 8) <= CART_DATA; end if; when others => null; end case; -- switchable XEGS or megacart disable/enable if (cart_type >= CART_TYPE_SW_XEGS_32K and cart_type <= CART_TYPE_SW_XEGS_1024K) then high_bank_enabled <= not CART_DATA(7); low_bank_enabled <= not CART_DATA(7); end if; if (cart_type >= CART_TYPE_MEGACART_16K and cart_type <= CART_TYPE_MEGACART_1024K) then high_bank_enabled <= not CART_DATA(7); low_bank_enabled <= not CART_DATA(7); end if; end if; -- (cart_rw_reg = '0') end if; -- (cart_ctl_reg = '0') -- bounty bob looks for specific accesses to the low bank if (cart_type = CART_TYPE_BOUNTY_BOB and cart_s4_reg = '0') then case ("000" & cart_addr_reg) is when X"0FF6" => bounty_bob_bank8 <= "00"; when X"0FF7" => bounty_bob_bank8 <= "01"; when X"0FF8" => bounty_bob_bank8 <= "10"; when X"0FF9" => bounty_bob_bank8 <= "11"; when X"1FF6" => bounty_bob_bank9 <= "00"; when X"1FF7" => bounty_bob_bank9 <= "01"; when X"1FF8" => bounty_bob_bank9 <= "10"; when X"1FF9" => bounty_bob_bank9 <= "11"; when others => null; end case; end if; end if; -- falling_edge(CART_PHI2) end if; end process; -- When we get a new address from the cartridge port, set up the RAM address bus -- to get the correct data process (cart_addr_reg, cart_s4_reg, cart_s5_reg, cart_ctl_reg, cart_type, bank_out, bounty_bob_bank8, bounty_bob_bank9, oss_bank) begin fpga_address_in <= (others => '0'); sram_address_in <= (others => '0'); sram_ce <= '0'; if (cart_type = CART_TYPE_BOOT) then fpga_address_in <= cart_addr_reg; elsif (cart_type = CART_TYPE_XEX) then if (cart_ctl_reg = '0' and cart_rw_reg = '1') then sram_ce <= '1'; sram_address_in <= file_offset(11 downto 0) & cart_addr_reg(7 downto 0); end if; elsif (cart_type /= CART_TYPE_NONE) then if (cart_s5_reg = '0' or cart_s4_reg = '0') then sram_ce <= '1'; end if; -- default case sram_address_in <= bank_out & cart_addr_reg; -- special cases (i.e. cartridges mapping both banks) case cart_type is when CART_TYPE_16K | CART_TYPE_BLIZZARD_16K => if (cart_s4_reg = '0') then sram_address_in <= "0000000" & cart_addr_reg; else sram_address_in <= "0000001" & cart_addr_reg; end if; when CART_TYPE_XEGS_32K | CART_TYPE_SW_XEGS_32K => if (cart_s5_reg = '0') then sram_address_in <= "0000011" & cart_addr_reg; end if; when CART_TYPE_XEGS_64K | CART_TYPE_SW_XEGS_64K => if (cart_s5_reg = '0') then sram_address_in <= "0000111" & cart_addr_reg; end if; when CART_TYPE_XEGS_128K | CART_TYPE_SW_XEGS_128K => if (cart_s5_reg = '0') then sram_address_in <= "0001111" & cart_addr_reg; end if; when CART_TYPE_XEGS_256K | CART_TYPE_SW_XEGS_256K => if (cart_s5_reg = '0') then sram_address_in <= "0011111" & cart_addr_reg; end if; when CART_TYPE_XEGS_512K | CART_TYPE_SW_XEGS_512K => if (cart_s5_reg = '0') then sram_address_in <= "0111111" & cart_addr_reg; end if; when CART_TYPE_XEGS_1024K | CART_TYPE_SW_XEGS_1024K => if (cart_s5_reg = '0') then sram_address_in <= "1111111" & cart_addr_reg; end if; when CART_TYPE_BOUNTY_BOB => if (cart_s5_reg = '0') then sram_address_in <= "0000100" & cart_addr_reg; else if (cart_addr_reg(12) = '0') then sram_address_in <= "000000" & bounty_bob_bank8 & cart_addr_reg(11 downto 0); -- 0x8000 access else sram_address_in <= "000001" & bounty_bob_bank9 & cart_addr_reg(11 downto 0); -- 0x9000 access end if; end if; when CART_TYPE_OSS_16K_TYPE_B | CART_TYPE_OSS_8K => if (cart_addr_reg(12) = '0') then if (cart_type = CART_TYPE_OSS_8K) then sram_address_in <= "0000000" & oss_bank(0) & cart_addr_reg(11 downto 0); -- 8k, 0xA000 access else sram_address_in <= "000000" & oss_bank & cart_addr_reg(11 downto 0); -- 16k, 0xA000 access end if; else sram_address_in <= "00000000" & cart_addr_reg(11 downto 0); -- 0xB000 access end if; when CART_TYPE_OSS_16K_034M | CART_TYPE_OSS_16K_043M => if (cart_addr_reg(12) = '0') then sram_address_in <= "000000" & oss_bank & cart_addr_reg(11 downto 0); -- 16k, 0xA000 access else sram_address_in <= "00000011" & cart_addr_reg(11 downto 0); -- 0xB000 access end if; when CART_TYPE_SIC | CART_TYPE_MEGACART_16K | CART_TYPE_MEGACART_32K | CART_TYPE_MEGACART_64K | CART_TYPE_MEGACART_128K | CART_TYPE_MEGACART_256K | CART_TYPE_MEGACART_512K | CART_TYPE_MEGACART_1024K => if (cart_s4_reg = '0') then sram_address_in <= bank_out(5 downto 0) & "0" & cart_addr_reg; else sram_address_in <= bank_out(5 downto 0) & "1" & cart_addr_reg; end if; when CART_TYPE_4k => sram_address_in <= "00000000" & cart_addr_reg(11 downto 0); -- 0xB000 access when others => null; end case; end if; -- cart_type /= CART_TYPE_NONE end process; -- When we get new data from RAM, pass it on to the cartridge port process (fpga_data_out, sram_data_out, cart_type, sic_read_d500) begin case cart_type is when CART_TYPE_NONE => data_out <= "00000000"; when CART_TYPE_BOOT => data_out <= fpga_data_out; when others => data_out <= sram_data_out; end case; if (sic_read_d500) then data_out <= sic_d500_byte; end if; end process; END structure;