Port | Read | Write |
#7Fxx | N/A | Standard RAM Expansion (512K) |
#DFxx | N/A | Upper ROM Bank |
#FD00-#FD05 | ? | ? |
#FD06 | IDE Alternate Status | IDE Digital Output |
#FD07 | IDE Drive Address | N/A |
#FD08 | IDE Data Register | IDE Data Register |
#FD09 | IDE Error Register | IDE Features Register (Write Precomp Reg.) |
#FD0A | IDE Sector Count | IDE Sector Count |
#FD0B | IDE Sector Number | IDE Sector Number |
#FD0C | IDE Cylinder Low | IDE Cylinder Low |
#FD0D | IDE Cylinder High | IDE Cylinder High |
#FD0E | IDE Device/Head Register | IDE Device/Head Register |
#FD0F | IDE Status Register | IDE Command Register |
#FD10 | PS/2 Mouse Status | N/A |
#FD11 | ROM Enable SYMBiFACE II Roms | ROM Disable SYMBiFACE II Roms |
#FD12-#FD13 | ? | ? |
#FD14 | RTC Data | RTC Data |
#FD15 | N/A | RTC Index |
#FD16 | ? | ? |
#FD17 | Map upper ROM to 4000h-7FFFh (for writing to ROMs) |
Don't map Upper ROM to 4000h-7FFFh (default) |
#FD18 | PS/2 Mouse Status | N/A |
#FD19-#FD3F | ? | ? |