src/mess/drivers/pc88va.c
| r9502 | r9503 | |
|---|
| 799 | 799 | case 0x00: return 0; // FDC mode register |
| 800 | 800 | case 0x02: return 0; // FDC control port 0 |
| 801 | 801 | case 0x04: return 0; // FDC control port 1 |
| 802 | | case 0x06: return 0; // FDC control port 2 |
| 802 | /* ---x ---- RDY: (0) Busy (1) Ready */ |
| 803 | case 0x06: // FDC control port 2 |
| 804 | return 0; |
| 803 | 805 | case 0x08: return upd765_status_r(space->machine->device("upd765"), 0); |
| 804 | 806 | case 0x0a: return upd765_data_r(space->machine->device("upd765"), 0); |
| 805 | 807 | } |
| r9502 | r9503 | |
|---|
| 811 | 813 | { |
| 812 | 814 | switch(offset*2) |
| 813 | 815 | { |
| 814 | | case 0x00: break; // FDC mode register |
| 815 | | case 0x02: break; // FDC control port 0 |
| 816 | | case 0x04: break; // FDC control port 1 |
| 817 | | case 0x06: break; // FDC control port 2 |
| 816 | /* |
| 817 | ---- ---x MODE: FDC op mode (0) Intelligent (1) DMA |
| 818 | */ |
| 819 | case 0x00: // FDC mode register |
| 820 | break; |
| 821 | /* |
| 822 | --x- ---- CLK: FDC clock selection (0) 4.8MHz (1) 8 MHz |
| 823 | ---x ---- DS1: Prohibition of the drive selection of FDC (0) Permission (1) Prohibition |
| 824 | ---- xx-- TD1/TD0: Drive 1/0 track density (0) 48 TPI (1) 96 TPI |
| 825 | ---- --xx RV1/RV0: Drive 1/0 mode selection (0) 2D and 2DD mode (1) 2HD mode |
| 826 | */ |
| 827 | case 0x02: // FDC control port 0 |
| 828 | break; |
| 829 | /* |
| 830 | ---- x--- PCM: ? |
| 831 | ---- --xx M1/M0: Drive 1/0 motor control (0) Motor OFF (1) Motor ON |
| 832 | */ |
| 833 | case 0x04: // FDC control port 1 |
| 834 | break; |
| 835 | /* |
| 836 | x--- ---- FDCRST: FDC Reset |
| 837 | -xx- ---- FDCFRY FRYCEN: FDC force ready control |
| 838 | ---x ---- DMAE: DMA Enable (0) Prohibit DMA (1) Enable DMA |
| 839 | ---- -x-- XTMASK: FDC timer IRQ mask (0) Disable (1) Enable |
| 840 | ---- ---x TTRG: FDC timer trigger (0) FDC timer clearing (1) FDC timer start |
| 841 | */ |
| 842 | case 0x06: |
| 843 | break; // FDC control port 2 |
| 818 | 844 | case 0x08: break; // UPD765 status |
| 819 | 845 | case 0x0a: upd765_data_w(space->machine->device("upd765"), 0,data); break; |
| 820 | 846 | } |