Mercurial > repos > blastem
annotate jcart.c @ 1637:95880d947257
Fix for VRAM byte write order broke VDP FIFO testing ROM results. This change cleans up VRAM writes and fixes the regression while preserving the correct VRAM byte write order
| author | Michael Pavone <pavone@retrodev.com> |
|---|---|
| date | Sun, 11 Nov 2018 22:39:29 -0800 |
| parents | 28ec17387be5 |
| children | 395f684c5379 |
| rev | line source |
|---|---|
| 1610 | 1 #include "genesis.h" |
| 2 | |
| 3 static io_port *get_ports(m68k_context *m68k) | |
| 4 { | |
| 5 genesis_context *gen = m68k->system; | |
| 6 if (!gen->extra) { | |
| 7 io_port *ports = calloc(2, sizeof(io_port)); | |
| 8 ports[0].device_type = IO_GAMEPAD3; | |
| 9 ports[0].device.pad.gamepad_num = 3; | |
| 10 ports[1].device_type = IO_GAMEPAD3; | |
| 11 ports[1].device.pad.gamepad_num = 4; | |
| 12 io_control_write(ports, 0x40, 0); | |
| 13 io_control_write(ports + 1, 0x40, 0); | |
| 14 gen->extra = ports; | |
| 15 } | |
| 16 | |
| 17 return gen->extra; | |
| 18 } | |
| 19 | |
| 20 void *jcart_write_w(uint32_t address, void *context, uint16_t value) | |
| 21 { | |
| 22 m68k_context *m68k= context; | |
| 23 io_port *ports = get_ports(m68k); | |
| 24 value = value << 6 & 0x40; | |
| 25 io_data_write(ports, value, m68k->current_cycle); | |
| 26 io_data_write(ports + 1, value, m68k->current_cycle); | |
| 27 return context; | |
| 28 } | |
| 29 | |
| 30 void *jcart_write_b(uint32_t address, void *context, uint8_t value) | |
| 31 { | |
| 32 if (address & 1) { | |
| 33 return jcart_write_w(address, context, value); | |
| 34 } | |
| 35 return context; | |
| 36 } | |
| 37 | |
| 38 uint16_t jcart_read_w(uint32_t address, void *context) | |
| 39 { | |
| 40 m68k_context *m68k= context; | |
| 41 io_port *ports = get_ports(m68k); | |
| 42 //according to Eke, bit 14 is forced low, at least on the Micro Machines 2 cart | |
| 43 //TODO: Test behavior of actual cart | |
|
1612
28ec17387be5
Remove stray / in jcart.c
Michael Pavone <pavone@retrodev.com>
parents:
1610
diff
changeset
|
44 uint16_t value = io_data_read(ports, m68k->current_cycle) << 8; |
| 1610 | 45 value |= io_data_read(ports + 1, m68k->current_cycle); |
| 46 return value; | |
| 47 } | |
| 48 | |
| 49 uint8_t jcart_read_b(uint32_t address, void *context) | |
| 50 { | |
| 51 m68k_context *m68k= context; | |
| 52 io_port *ports = get_ports(m68k); | |
| 53 return io_data_read(ports + (address & 1), m68k->current_cycle); | |
| 54 } | |
| 55 | |
| 56 void jcart_adjust_cycles(genesis_context *context, uint32_t deduction) | |
| 57 { | |
| 58 io_port *ports = get_ports(context->m68k); | |
| 59 io_adjust_cycles(ports, context->m68k->current_cycle, deduction); | |
| 60 io_adjust_cycles(ports + 1, context->m68k->current_cycle, deduction); | |
| 61 } | |
| 62 | |
| 63 void jcart_gamepad_down(genesis_context *context, uint8_t gamepad_num, uint8_t button) | |
| 64 { | |
| 65 io_port *ports = get_ports(context->m68k); | |
| 66 if (gamepad_num == ports[1].device.pad.gamepad_num) { | |
| 67 ports++; | |
| 68 } else if (gamepad_num != ports[0].device.pad.gamepad_num) { | |
| 69 ports = NULL; | |
| 70 } | |
| 71 if (ports) { | |
| 72 io_port_gamepad_down(ports, button); | |
| 73 } | |
| 74 } | |
| 75 | |
| 76 void jcart_gamepad_up(genesis_context *context, uint8_t gamepad_num, uint8_t button) | |
| 77 { | |
| 78 io_port *ports = get_ports(context->m68k); | |
| 79 if (gamepad_num == ports[1].device.pad.gamepad_num) { | |
| 80 ports++; | |
| 81 } else if (gamepad_num != ports[0].device.pad.gamepad_num) { | |
| 82 ports = NULL; | |
| 83 } | |
| 84 if (ports) { | |
| 85 io_port_gamepad_up(ports, button); | |
| 86 } | |
| 87 } |