Changes
{|{{Prettytable|width: 700px; font-size: 2em;}}
|'''Port''' || '''Read''' || '''Write'''
|-
|'''#7Fxx''' ||N/A ||Standard RAM Expansion (512K)
|-
|'''#FD00-#FD05''' ||? ||?
|-
|'''#FD06''' ||IDE Alternate Status ||IDE Digital Output
|-
|'''#FD10''' ||PS/2 Mouse Status||Write: Not used
|-
|'''#FD11''' ||ROM Enable SYMBiFACE II roms||ROM Disable all SYMBiFACE II Roms
|-
|'''#FD12-#FD13''' ||? ||?
|-
|'''#FD14''' ||RTC Data ||RTC Data
|-
|'''#FD15''' ||Read: Not used ||RTC Index
|-
|'''#FD16''' ||? ||?
|-
|'''#FD17''' ||ROM Map upper ROM to 4000h-7FFFh (for writing to FLASH ROMs)||ROM Don't map ROM to 4000h-7FFFh (default)
|-
|'''#FD17-#FD3F''' ||? ||?
|}
