Here is the start of a listing of the reserved I/O space at the top of the Color Computer memory map. I am still looking for more information on devices that are not listed here, so if anyone has any feel free to email me and I will add it to the list. For now the list is just showing a brief description, if I get ambitious in the future I may link off this list to more specific descriptions on this site or others.
| Hex Address | Decimal Address | Device | Description |
| FF00 | 65280 | CoCo 1,2,3 | Keyboard Rows Bit 0 - 6, Bit 7 Joystick comparison input |
| FF01 | 65281 | CoCo 1,2,3 | Horizontal Sync Clock Interrupt input, SEL 1 |
| FF02 | 65283 | CoCo 1,2,3 | Keyboard Columns |
| FF03 | 65284 | CoCo 1,2,3 | Field Sync Interrupt input, SEL 2 |
| FF20 | 65312 | CoCo 1,2,3 | 6 Bit D/A, RS-232 Output, Cassette Data input |
| FF21 | 65313 | CoCo 1,2,3 | RS-232 CD Status, Cassette Motor control |
| FF22 | 65314 | CoCo 1,2,3 | RS-232 Data Input, Single Bit Sound output, Ram Size input, VDG Control |
| FF23 | 65315 | CoCo 1,2,3 | Cartridge Interrupt, 6 Bit Sound enable |
| FF40-FF4F | 65344-65359 | Drive Controller | |
| FF50-FF5F | 65360-65375 | Drive Controller, Disto | |
| FF50-FF57 | 65360-65367 | Disto Mini Expansion Bus | |
| FF50-FF58 | 65360-65368 | IDE Controller | Default Address |
| FF60-FF7F | 65376-65407 | TC^3 SCSI Interface | Two addresses used in this range |
| FF60 | 65376 | X - Pad | X Axis Data |
| FF61 | 65377 | X - Pad | Y Axis Data |
| FF62 | 65378 | X - Pad | Pen Status |
| FF63 | 65379 | X - Pad | Unused |
| FF68 | 65384 | RS-232 Pak | Data |
| FF69 | 65385 | RS-232 Pak | Write Soft Reset, Read Status Register |
| FF6A | 65386 | RS-232 Pak | Command Register |
| FF6B | 65387 | RS-232 Pak | Control Register |
| FF6C-FF6F | 65388-65391 | Modem Pak | |
| FF70-FF78 | 65392-65400 | IDE Controller | Alternate Address |
| FF70 | 65392 | LR Tech SASI | Alternate Address |
| FF74 | 65396 | LR Tech SASI | Default Address |
| FF74-FF77 | 65396-65399 | Disto SCII Haltless Controller | Additional Addresses |
| FF7A | 65402 | Orchestra 90 Pak | Left Channel D/A |
| FF7B | 65403 | Orchestra 90 Pak | Right Channel D/A |
| FF7D | 65405 | Speech/Sound Pak | Software Reset |
| FF7E | 65406 | Speech/Sound Pak | Data and Status |
| FF7F | 65407 | Multi-pak Interface | Slot Select |
| FF90 | 65424 | CoCo 3 | Initialization Register 0 |
| FF91 | 65425 | CoCo 3 | Initialization Register 1 |
| FF92 | 65426 | CoCo 3 | IRQ Enable |
| FF93 | 65427 | CoCo3 | FIRQ Enable |
| FF94 | 65428 | CoCo 3 | Timer MSN (Most Significant Nibble) |
| FF95 | 65429 | CoCo 3 | Timer LSB |
| FF98 | 65432 | CoCo 3 | Video Mode Register |
| FF99 | 65433 | CoCo 3 | Video Resolution Register |
| FF9A | 65434 | CoCo 3 | Border Register |
| FF9B | 65435 | CoCo3/ 2 Mb Memory, NoCan Series to 8 Mb | Bits 0 - 5 |
| FF9C | 65436 | CoCo 3 | Vertical Scroll Register |
| FF9D | 65437 | CoCo 3 | Vertical Offset 1 Register |
| FF9E | 65438 | CoCo 3 | Vertical Offset 0 Register |
| FF9F | 65439 | CoCo 3 | Horizontal Offset 0 Register |
| FFA0-FFA8 | 65440-65448 | CoCo 3 | MMU |
| FFA9-FFAF | 65449-65455 | CoCo 3 | MMU |
| FFB0-FFBF | 65456-65471 | CoCo 3 | Palette Registers |
| FFC0 | 65472 | CoCo 1,2,3 | Display Mode Control |
| FFC1 | 65473 | CoCo 1,2,3 | Display Mode Control |
| FFC2 | 65474 | CoCo 1,2,3 | Display Mode Control |
| FFC3 | 65475 | CoCo 1,2,3 | Display Mode Control |
| FFC4 | 65476 | CoCo 1,2,3 | Display Mode Control |
| FFC5 | 65477 | CoCo 1,2,3 | Display Mode Control |
| FFC6 | 65478 | CoCo 1,2,3 | Display Offset |
| FFC7 | 65479 | CoCo 1,2,3 | Display Offset |
| FFC8 | 65480 | CoCo 1,2,3 | Display Offset |
| FFC9 | 65481 | CoCo 1,2,3 | Display Offset |
| FFCA | 65482 | CoCo 1,2,3 | Display Offset |
| FFCB | 65483 | CoCo 1,2,3 | Display Offset |
| FFCC | 65484 | CoCo 1,2,3 | Display Offset |
| FFCD | 65485 | CoCo 1,2,3 | Display Offset |
| FFCE | 65486 | CoCo 1,2,3 | Display Offset |
| FFCF | 65487 | CoCo 1,2,3 | Display Offset |
| FFD0 | 65488 | CoCo 1,2,3 | Display Offset |
| FFD1 | 65489 | CoCo1,2,3 | Display Offset |
| FFD2 | 65490 | CoCo 1,2,3 | Display Offset |
| FFD3 | 65491 | CoCo 1,2,3 | Display Offset |
| FFD4 | 65492 | CoCo 1,2 | Page 1 |
| FFD5 | 65493 | CoCo 1,2 | Page 1 |
| FFD6 | 65494 | CoCo 1,2 | CPU Rate |
| FFD7 | 65495 | CoCo 1,2 | CPU Rate |
| FFD8 | 65496 | CoCo 1,2,3 | CPU Rate |
| FFD9 | 65497 | CoCo 1,2,3 | CPU Rate |
| FFDA | 65498 | CoCo 1,2 | Memory size |
| FFDB | 65499 | CoCo 1,2 | Memory size |
| FFDC | 65500 | CoCo 1,2 | Memory Size |
| FFDD | 65501 | CoCo 1,2 | Memory Size |
| FFDE | 65502 | CoCo 1,2,3 | Map Type |
| FFDF | 65503 | CoCo 1,2,3 | Map Type |
| FFF0 | 65520 | 6309 | Exception Vector MSB |
| FFF1 | 65521 | 6309 | Exception Vector LSB |
| FFF2 | 65522 | CoCo 1,2,3 | SWI3 Vector MSB |
| FFF3 | 65523 | CoCo 1,2,3 | SWI3 Vector LSB |
| FFF4 | 65524 | CoCo 1,2,3 | SWI2 Vector MSB |
| FFF5 | 65525 | CoCo 1,2,3 | SWI2 Vector LSB |
| FFF6 | 65526 | CoCo 1,2,3 | FIRQ Vector MSB |
| FFF7 | 65527 | CoCo 1,2,3 | FIRQ Vector LSB |
| FFF8 | 65528 | CoCo 1,2,3 | IRQ Vector MSB |
| FFF9 | 65529 | CoCo 1,2,3 | IRQ Vector LSB |
| FFFA | 65530 | CoCo 1,2,3 | SWI1 Vector MSB |
| FFFB | 65531 | CoCo 1,2,3 | SWI1 Vector LSB |
| FFFC | 65532 | CoCo 1,2,3 | NMI Vector MSB |
| FFFD | 65533 | CoCo 1,2,3 | NMI Vector LSB |
| FFFE | 65534 | CoCo 1,2,3 | RESET Vector MSB |
| FFFF | 65535 | CoCo 1,2,3 | RESET Vector LSB |