Fixes s'more (Kingsoft Business Basic) cartridge.

markusC64 · Sep 9, 2021 · be804d2 · be804d2
1 parent 708055d
commit be804d2
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Showing 2 changed files with 10 additions and 5 deletions.
diff --git a/fpga/cart_slot/vhdl_source/all_carts_v5.vhd b/fpga/cart_slot/vhdl_source/all_carts_v5.vhd
@@ -268,13 +268,11 @@ begin
 
             when c_bbasic => -- Write IO1 = off, Read IO1 = ON
                 if io_write='1' and io_addr(8)='0' then
-                    mode_bits(0) <= '1';
-                    bank_bits(14) <= '1';
-                elsif io_read='1' and io_addr(8)='0' then
                     mode_bits(0) <= '0';
-                    bank_bits(14) <= '0';
+                elsif io_read='1' and io_addr(8)='0' then
+                    mode_bits(0) <= '1';
                 end if;
-                if mode_bits(0)='0' then -- ROM mode  (starts in ROM mode?)
+                if mode_bits(0)='1' then
                    game_n    <= '0';
                    exrom_n   <= '0';
                 -- Dynamic mode, Ultimax in ranges 8000, A000 and E000.  How about writes?
@@ -286,6 +284,9 @@ begin
                    exrom_n   <= '1';
                 end if;
                 serve_rom <= '1';
+                serve_io1 <= '1';
+                rom_mode  <= "11"; -- 32K! The ROMs shall be placed in memory at the right location by the software.
+                -- Note that the CRT files are usually wrong; they list 3 banks of 8K, all at $8000, which is incorrect.
 
             when c_blackbox_v3 =>
                 if io_write='1' and io_addr(8)='0' then -- write IO1 => disable

diff --git a/software/io/c64/c64_crt.cc b/software/io/c64/c64_crt.cc
@@ -482,6 +482,10 @@ void C64_CRT::configure_cart(cart_def *def)
         case CART_BBASIC:
             cart_type = CART_TYPE_BBASIC; // Business Basic
             prohibit = CART_PROHIBIT_DEXX;
+            // CHIPs have been loaded at 0000, 4000 and 8000; while they should be at 0000, 2000 and 6000
+            // So source and destinations do not overlap; we can simply copy the data
+            memcpy(cart_memory + 0x2000, cart_memory + 0x4000, 0x2000);
+            memcpy(cart_memory + 0x6000, cart_memory + 0x8000, 0x2000);
             break;
         case CART_PAGEFOX:
             cart_type = CART_TYPE_PAGEFOX; // Pagefox