trunk/src/mame/machine/naomim2.cpp
| r250234 | r250235 | |
|---|
| 11 | 11 | |
| 12 | 12 | NAOMI_ROM_OFFSET bit29: ROM size/mapping selection, 0 - 4MB ROM mode, 1 - 8MB ROM mode |
| 13 | 13 | |
| 14 | bit28: Bank selection. |
| 15 | in the case of flash-based 171-7885A ROM boards two of them can be stacked at once |
| 16 | onto main board. each must be configured as Bank 0 or 1 via some (currently unknown) jumper. |
| 17 | this bit selects which one ROM board will be accessed. |
| 18 | |
| 14 | 19 | note: if ROM is not mounted its area readed as 0xFF |
| 15 | 20 | |
| 16 | 21 | 8MB ROM mode: |
| r250234 | r250235 | |
|---|
| 166 | 171 | void naomi_m2_board::board_write(offs_t offset, UINT16 data) |
| 167 | 172 | { |
| 168 | 173 | if(offset & 0x40000000) { |
| 169 | | if((offset & 0x0f000000) == 0x02000000) { |
| 174 | if(offset & 0x00020000) { |
| 170 | 175 | offset &= RAM_SIZE-1; |
| 171 | 176 | ram[offset] = data; |
| 172 | 177 | ram[offset+1] = data >> 8; |
| 173 | 178 | return; |
| 174 | 179 | } |
| 175 | | switch(offset & 0x1fffffff) { |
| 180 | switch(offset & 0x1ffff) { |
| 176 | 181 | case 0x1fff8: m_cryptdevice->set_addr_low(data); return; |
| 177 | 182 | case 0x1fffa: m_cryptdevice->set_addr_high(data); return; |
| 178 | 183 | case 0x1fffc: m_cryptdevice->set_subkey(data); return; |