diff options
| author | Mike Pavone <pavone@retrodev.com> | 2012-12-28 20:46:29 -0800 |
|---|---|---|
| committer | Mike Pavone <pavone@retrodev.com> | 2012-12-28 20:46:29 -0800 |
| commit | d168bccaf1d55ddb414f67adb5881dd5b5139ecb (patch) | |
| tree | 67427bcedfa552d9ad14d496b0ecf6900da4493e /blastem.c | |
| parent | f18f61486c979c1955bab5549ef05a985d45fc05 (diff) | |
Fix Z80 busreq logic
Diffstat (limited to 'blastem.c')
| -rw-r--r-- | blastem.c | 24 |
1 files changed, 11 insertions, 13 deletions
@@ -284,22 +284,21 @@ m68k_context * io_write(uint32_t location, m68k_context * context, uint8_t value busreq = 1; if(!reset) { busack_cycle = context->current_cycle + Z80_ACK_DELAY; - new_busack = 1; + new_busack = 0; } } else { busreq = 0; busack_cycle = CYCLE_NEVER; - busack = 0; + busack = 1; } } else if (location == 0x1200) { if (value & 1) { if (reset && busreq) { - new_busack = 1; + new_busack = 0; busack_cycle = context->current_cycle + Z80_ACK_DELAY; } reset = 0; } else { - busack = 0; reset = 1; } } @@ -328,7 +327,7 @@ m68k_context * io_write_w(uint32_t location, m68k_context * context, uint16_t va break; } } else { - //printf("IO Write of %X to %X\n", value, location); + printf("IO Write of %X to %X @ %d\n", value, location, context->current_cycle); if (location == 0x1100) { if (busack_cycle > context->current_cycle) { busack = new_busack; @@ -338,22 +337,21 @@ m68k_context * io_write_w(uint32_t location, m68k_context * context, uint16_t va busreq = 1; if(!reset) { busack_cycle = context->current_cycle + Z80_ACK_DELAY; - new_busack = 1; + new_busack = 0; } } else { busreq = 0; busack_cycle = CYCLE_NEVER; - busack = 0; + busack = 1; } } else if (location == 0x1200) { if (value & 0x100) { if (reset && busreq) { - new_busack = 1; + new_busack = 0; busack_cycle = context->current_cycle + Z80_ACK_DELAY; } reset = 0; } else { - busack = 0; reset = 1; } } @@ -392,8 +390,8 @@ m68k_context * io_read(uint32_t location, m68k_context * context) busack = new_busack; busack_cycle = CYCLE_NEVER; } - context->value = (!reset) && busack; - //printf("Byte read of BUSREQ returned %d\n", context->value); + context->value = reset || busack; + printf("Byte read of BUSREQ returned %d @ %d (reset: %d, busack: %d)\n", context->value, context->current_cycle, reset, busack); } else if (location == 0x1200) { context->value = !reset; } else { @@ -440,8 +438,8 @@ m68k_context * io_read_w(uint32_t location, m68k_context * context) busack = new_busack; busack_cycle = CYCLE_NEVER; } - context->value = ((!reset) && busack) << 8; - //printf("Word read of BUSREQ returned %d\n", context->value); + context->value = (reset || busack) << 8; + printf("Word read of BUSREQ returned %d\n", context->value); } else if (location == 0x1200) { context->value = (!reset) << 8; } else { |