| 1 | /* |
| 2 | * PicoDrive |
| 3 | * (C) notaz, 2008 |
| 4 | * |
| 5 | * This work is licensed under the terms of MAME license. |
| 6 | * See COPYING file in the top-level directory. |
| 7 | */ |
| 8 | #include "../pico_int.h" |
| 9 | |
| 10 | // x: 0x03c - 0x19d |
| 11 | // y: 0x1fc - 0x2f7 |
| 12 | // 0x2f8 - 0x3f3 |
| 13 | picohw_state PicoPicohw; |
| 14 | |
| 15 | static int prev_line_cnt_irq3 = 0, prev_line_cnt_irq5 = 0; |
| 16 | static int fifo_bytes_line = (16000<<16)/60/262/2; |
| 17 | |
| 18 | static const int guessed_rates[] = { 8000, 14000, 12000, 14000, 16000, 18000, 16000, 16000 }; // ? |
| 19 | |
| 20 | #define PICOHW_FIFO_IRQ_THRESHOLD 12 |
| 21 | |
| 22 | PICO_INTERNAL void PicoReratePico(void) |
| 23 | { |
| 24 | int rate = guessed_rates[PicoPicohw.r12 & 7]; |
| 25 | if (Pico.m.pal) |
| 26 | fifo_bytes_line = (rate<<16)/50/312/2; |
| 27 | else fifo_bytes_line = (rate<<16)/60/262/2; |
| 28 | PicoPicoPCMRerate(rate); |
| 29 | } |
| 30 | |
| 31 | static void PicoLinePico(void) |
| 32 | { |
| 33 | PicoPicohw.line_counter++; |
| 34 | |
| 35 | #if 1 |
| 36 | if ((PicoPicohw.r12 & 0x4003) && PicoPicohw.line_counter - prev_line_cnt_irq3 > 200) { |
| 37 | prev_line_cnt_irq3 = PicoPicohw.line_counter; |
| 38 | // just a guess/hack, allows 101 Dalmantians to boot |
| 39 | elprintf(EL_PICOHW, "irq3"); |
| 40 | SekInterrupt(3); |
| 41 | return; |
| 42 | } |
| 43 | #endif |
| 44 | |
| 45 | if (PicoPicohw.fifo_bytes > 0) |
| 46 | { |
| 47 | PicoPicohw.fifo_line_bytes += fifo_bytes_line; |
| 48 | if (PicoPicohw.fifo_line_bytes >= (1<<16)) { |
| 49 | PicoPicohw.fifo_bytes -= PicoPicohw.fifo_line_bytes >> 16; |
| 50 | PicoPicohw.fifo_line_bytes &= 0xffff; |
| 51 | if (PicoPicohw.fifo_bytes < 0) |
| 52 | PicoPicohw.fifo_bytes = 0; |
| 53 | } |
| 54 | } |
| 55 | else |
| 56 | PicoPicohw.fifo_line_bytes = 0; |
| 57 | |
| 58 | #if 1 |
| 59 | if (PicoPicohw.fifo_bytes_prev >= PICOHW_FIFO_IRQ_THRESHOLD && |
| 60 | PicoPicohw.fifo_bytes < PICOHW_FIFO_IRQ_THRESHOLD) { |
| 61 | prev_line_cnt_irq3 = PicoPicohw.line_counter; // ? |
| 62 | elprintf(EL_PICOHW, "irq3, fb=%i", PicoPicohw.fifo_bytes); |
| 63 | SekInterrupt(3); |
| 64 | } |
| 65 | PicoPicohw.fifo_bytes_prev = PicoPicohw.fifo_bytes; |
| 66 | #endif |
| 67 | |
| 68 | #if 0 |
| 69 | if (PicoPicohw.line_counter - prev_line_cnt_irq5 > 512) { |
| 70 | prev_line_cnt_irq5 = PicoPicohw.line_counter; |
| 71 | elprintf(EL_PICOHW, "irq5"); |
| 72 | SekInterrupt(5); |
| 73 | } |
| 74 | #endif |
| 75 | } |
| 76 | |
| 77 | static void PicoResetPico(void) |
| 78 | { |
| 79 | PicoPicoPCMReset(); |
| 80 | PicoPicohw.xpcm_ptr = PicoPicohw.xpcm_buffer; |
| 81 | } |
| 82 | |
| 83 | PICO_INTERNAL void PicoInitPico(void) |
| 84 | { |
| 85 | elprintf(EL_STATUS, "Pico startup"); |
| 86 | PicoLineHook = PicoLinePico; |
| 87 | PicoResetHook = PicoResetPico; |
| 88 | |
| 89 | PicoAHW = PAHW_PICO; |
| 90 | memset(&PicoPicohw, 0, sizeof(PicoPicohw)); |
| 91 | PicoPicohw.pen_pos[0] = 0x03c + 320/2; |
| 92 | PicoPicohw.pen_pos[1] = 0x200 + 240/2; |
| 93 | prev_line_cnt_irq3 = prev_line_cnt_irq5 = 0; |
| 94 | |
| 95 | // map version register |
| 96 | PicoDetectRegion(); |
| 97 | switch (Pico.m.hardware >> 6) { |
| 98 | case 0: PicoPicohw.r1 = 0x00; break; |
| 99 | case 1: PicoPicohw.r1 = 0x00; break; |
| 100 | case 2: PicoPicohw.r1 = 0x40; break; |
| 101 | case 3: PicoPicohw.r1 = 0x20; break; |
| 102 | } |
| 103 | } |
| 104 | |