The is a list of all known I/O ports of the Amstrad CPC (copied from the FutureOS manual).
| I/O | Port | Read | Write |
| #7FXX | Gate Array | Write | |
| #BCXX | 6845 CRTC Address-Register | - | Write |
| #BDXX | 6845 CRTC Data-Register | - | Write |
| #BEXX | 6845 CRTC Status-Register | Read | - |
| #BFXX | 6845 CRTC Video-Address-Register | Read | - |
| #BDXX | select ROM | - | Write |
| #EFXX | Printer Port | - | Write |
| #F4XX | 8255 PIO Port A | Read | Write |
| #F5XX | 8255 PIO Port B | Read | - |
| #F6XX | 8255 PIO Port C | - | Write |
| #F7XX | 8255 PIO Control-Register | - | Write |
| #F8B0 | Vidi-CPC Video-Digitiser | ? | ? |
| #F8B1 | Vidi-CPC Video-Digitiser | ? | ? |
| #F8DC - #F8DD | CPCI Serial Interface | Read | Write |
| #F8E0 | Z80 STI Indirect Data Register | Read | Write |
| #F8E1 | Z80 STI Gen. Purpose I/O Interrupt | Read | Write |
| #F8E8 | Z80 STI Pointer Vector Register | Read | Write |
| #F8E8 | Music Machine | - | Write |
| #F8EC | Z80 STI USART Control Register | Read | Write |
| #F8EC | Music Machine | - | Write |
| #F8ED | Z80 STI Receiver Status Register | Read | Write |
| #F8EE | Z80 STI Transmitter Status Register | Read | Write |
| #F8EF | Z80 STI USART Data Register | Read | Write |
| #F8EF | Music Machine | Read | - |
| #F8E2 - #F8E4 | Dobbertin Eprommer 4003 | ? | ? |
| #F8F0 | Music Machine | - | Write |
| #F8F2 | Dobbertin Eprommer 4003 | ? | ? |
| #F8F4 | Music Machine | Read | - |
| #F8F8 | Music Machine | - | Write |
| #F9B0 | Vidi-CPC Video-Digitiser | ? | ? |
| #F9FC - #F9FE | Otten & Fecht 1 MB RAM-Disc | ? | ? |
| #FA7E | Floppy Motor Control | - | Write |
| #FADC | Z80-SIO / DART port A Data Register | Read | Write |
| #FADD | Z80-SIO / DART port A Control Reg. | Read | Write |
| #FADE | Z80-SIO / DART port B Data Register | Read | Write |
| #FADF | Z80-SIO / DART port B Control Reg. | Read | Write |
| #FB7E | 765 FDC (internal) Status Register | Read | - |
| #FB7F | 765 FDC (internal) Data Register | Read | Write |
| #FBDC | 8253 Timer counter 0 | Read | Write |
| #FBDD | 8253 Timer counter 1 | Read | Write |
| #FBDE | 8253 Timer counter 2 | Read | Write |
| #FBDF | 8253 Timer Modus Select | - | Write |
| #FBE0 | Hard Disc Data Port | Read | Write |
| #FBE1 | Hard Disc Status, Reset | Read | Write |
| #FBE2 | Hard Disc Select, Configuration | Read | Write |
| #FBE3 | Hard Disc DMA, Interrupt | Read | Write |
| #FBE4 | Hard Disc Reset | Read | Write |
| #FBE0 - #FBE3 | dk'tronics RTC. | ? | ? |
| &FBE8 | dk'tronics RTC. | ? | ? |
| #FBEE | SSA1 dk'tronics Speech-Module | Read | Write |
| #FBF0 - #FBFF | Otten & Fecht 1 MB RAM-Disc | ? | ? |
| #FBF6 | 765 FDC (Vortex,ext) Status Register | Read | - |
| #FBF7 | 765 FDC (Vortex,ext) Data Register | Read | Write |
| #FD00 - #FD3F | SYMBiFACE II | Read | Write |
| #FEE8 | Multiface II | ? | ? |
| #FEEA | Multiface II | ? | ? |
| #FFxx | CPC Booster | Read | Write |