diff options
Diffstat (limited to 'genesis.c')
| -rw-r--r-- | genesis.c | 19 |
1 files changed, 17 insertions, 2 deletions
@@ -519,6 +519,10 @@ static m68k_context * vdp_port_write(uint32_t vdp_port, m68k_context * context, if (vdp_port & 0x2700E0) { fatal_error("machine freeze due to write to address %X\n", 0xC00000 | vdp_port); } + genesis_context * gen = context->system; + if (!gen->vdp_unlocked) { + fatal_error("machine freeze due to VDP write to %X without TMSS unlock\n", 0xC00000 | vdp_port); + } vdp_port &= 0x1F; //printf("vdp_port write: %X, value: %X, cycle: %d\n", vdp_port, value, context->current_cycle); #ifdef REFRESH_EMULATION @@ -529,7 +533,6 @@ static m68k_context * vdp_port_write(uint32_t vdp_port, m68k_context * context, last_sync_cycle = context->current_cycle; #endif sync_components(context, 0); - genesis_context * gen = context->system; vdp_context *v_context = gen->vdp; uint32_t before_cycle = v_context->cycles; if (vdp_port < 0x10) { @@ -658,6 +661,10 @@ static uint16_t vdp_port_read(uint32_t vdp_port, m68k_context * context) if (vdp_port & 0x2700E0) { fatal_error("machine freeze due to read from address %X\n", 0xC00000 | vdp_port); } + genesis_context *gen = context->system; + if (!gen->vdp_unlocked) { + fatal_error("machine freeze due to VDP read from %X without TMSS unlock\n", 0xC00000 | vdp_port); + } vdp_port &= 0x1F; uint16_t value; #ifdef REFRESH_EMULATION @@ -668,7 +675,6 @@ static uint16_t vdp_port_read(uint32_t vdp_port, m68k_context * context) last_sync_cycle = context->current_cycle; #endif sync_components(context, 0); - genesis_context *gen = context->system; vdp_context * v_context = gen->vdp; uint32_t before_cycle = v_context->cycles; if (vdp_port < 0x10) { @@ -1168,6 +1174,11 @@ static uint8_t unused_read_b(uint32_t location, void *vcontext) } } +static void check_tmss_lock(genesis_context *gen) +{ + gen->vdp_unlocked = gen->tmss_lock[0] == 'SE' && gen->tmss_lock[1] == 'GA'; +} + static void *unused_write(uint32_t location, void *vcontext, uint16_t value) { m68k_context *context = vcontext; @@ -1175,6 +1186,7 @@ static void *unused_write(uint32_t location, void *vcontext, uint16_t value) uint8_t has_tmss = gen->version_reg & 0xF; if (has_tmss && (location == 0xA14000 || location == 0xA14002)) { gen->tmss_lock[location >> 1 & 1] = value; + check_tmss_lock(gen); } else if (has_tmss && location == 0xA14100) { value &= 1; if (gen->tmss != value) { @@ -1209,6 +1221,7 @@ static void *unused_write_b(uint32_t location, void *vcontext, uint8_t value) gen->tmss_lock[offset] &= 0xFF; gen->tmss_lock[offset] |= value << 8; } + check_tmss_lock(gen); } else if (has_tmss && (location == 0xA14100 || location == 0xA14101)) { if (location & 1) { value &= 1; @@ -1737,6 +1750,8 @@ genesis_context *alloc_init_genesis(rom_info *rom, void *main_rom, void *lock_on uint8_t tmss = !strcmp(tern_find_ptr_default(model, "tmss", "off"), "on"); if (tmss) { gen->version_reg |= 1; + } else { + gen->vdp_unlocked = 1; } uint8_t max_vsram = !strcmp(tern_find_ptr_default(model, "vsram", "40"), "64"); |