diff options
Diffstat (limited to 'src/mame/machine/btime.c')
-rw-r--r-- | src/mame/machine/btime.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/src/mame/machine/btime.c b/src/mame/machine/btime.c new file mode 100644 index 00000000000..2d2c815ec5e --- /dev/null +++ b/src/mame/machine/btime.c @@ -0,0 +1,93 @@ + +#include "driver.h" + + +#define BASE 0xb000 + + +static int protection_command; +static int protection_status = 0; +static int protection_value; +static int protection_ret = 0; + + +READ8_HANDLER( mmonkey_protection_r ) +{ + UINT8 *RAM = memory_region(REGION_CPU1); + + int ret = 0; + + if (offset == 0x0000) ret = protection_status; + else if (offset == 0x0e00) ret = protection_ret; + else if (offset >= 0x0d00 && offset <= 0x0d02) ret = RAM[BASE+offset]; /* addition result */ + else logerror("Unknown protection read. PC=%04X Offset=%04X\n", activecpu_get_pc(), offset); + + return ret; +} + + + +WRITE8_HANDLER( mmonkey_protection_w ) +{ + UINT8 *RAM = memory_region(REGION_CPU1); + + + if (offset == 0) + { + /* protection trigger */ + if (data == 0) + { + int i,s1,s2,r; + + switch (protection_command) + { + case 0: /* score addition */ + + s1 = ( 1 * (RAM[BASE+0x0d00] & 0x0f)) + ( 10 * (RAM[BASE+0x0d00] >> 4)) + + ( 100 * (RAM[BASE+0x0d01] & 0x0f)) + ( 1000 * (RAM[BASE+0x0d01] >> 4)) + + (10000 * (RAM[BASE+0x0d02] & 0x0f)) + (100000 * (RAM[BASE+0x0d02] >> 4)); + + s2 = ( 1 * (RAM[BASE+0x0d03] & 0x0f)) + ( 10 * (RAM[BASE+0x0d03] >> 4)) + + ( 100 * (RAM[BASE+0x0d04] & 0x0f)) + ( 1000 * (RAM[BASE+0x0d04] >> 4)) + + (10000 * (RAM[BASE+0x0d05] & 0x0f)) + (100000 * (RAM[BASE+0x0d05] >> 4)); + + r = s1 + s2; + + RAM[BASE+0x0d00] = (r % 10); r /= 10; + RAM[BASE+0x0d00] |= ((r % 10) << 4); r /= 10; + RAM[BASE+0x0d01] = (r % 10); r /= 10; + RAM[BASE+0x0d01] |= ((r % 10) << 4); r /= 10; + RAM[BASE+0x0d02] = (r % 10); r /= 10; + RAM[BASE+0x0d02] |= ((r % 10) << 4); + + break; + + case 1: /* decryption */ + + /* Compute return value by searching the decryption table. */ + /* During the search the status should be 2, but we're done */ + /* instanteniously in emulation time */ + for (i = 0; i < 0x100; i++) + { + if (RAM[BASE+0x0f00+i] == protection_value) + { + protection_ret = i; + break; + } + } + break; + + default: + logerror("Unemulated protection command=%02X. PC=%04X\n", protection_command, activecpu_get_pc()); + break; + } + + protection_status = 0; + } + } + else if (offset == 0x0c00) protection_command = data; + else if (offset == 0x0e00) protection_value = data; + else if (offset >= 0x0f00) RAM[BASE+offset] = data; /* decrypt table */ + else if (offset >= 0x0d00 && offset <= 0x0d05) RAM[BASE+offset] = data; /* source table */ + else logerror("Unknown protection write=%02X. PC=%04X Offset=%04X\n", data, activecpu_get_pc(), offset); +} |