| Porty | Význam |
|---|
| 00h | Channel 0 Base and Current Address Register |
| 01h | Channel 0 Base and Current Word Count Register |
| 02h | Channel 1 Base and Current Address Register |
| 03h | Channel 1 Base and Current Word Count Register |
| 04h | Channel 2 Base and Current Address Register |
| 05h | Channel 2 Base and Current Word Count Register |
| 06h | Channel 3 Base and Current Address Register |
| 07h | Channel 3 Base and Current Word Count Register |
| 08h | Read Status Register/Write Command Register |
| 09h | Write Request Register |
| 0Ah | Write Single Mask Register Bit |
| 0Bh | Write Mode Register |
| 0Ch | Clear Byte Pointer Flip-flop |
| 0Dh | Read Temporary Register/Write Master Clear |
| 0Eh | Clear Mask Register |
| 0Fh | Write All Mask Register Bits |
| 10h - 1Fh | PIO(Programmed-I/O) / SCB(Subsystem Control Block) DMA Interface
| 10h - 17h | Reserved |
| 18h | Function register (PIO:WO, SCB:R/W) |
| 19h | Extended function register (SCB:R/W) |
| 1Ah | Execute function port (PIO:R/W, SCB:R/W) |
| 1Bh | Reserved |
| 1Ch | Attention register (SCB:WO) |
| 1Dh | Subsystem control register (SCB:WO) |
| 1Eh | Reserved |
| 1Fh | Command busy/Status register (SCB:RO) |
|
| Porty | Význam |
|---|
| 60h |
AT Keyboard Input Port
| bit | význam | hodnoty |
|---|
| 7 | Keyboard inhibit switch | 1=not inhibited |
| 6 | Display switch | 1=MDA, 0=CGA |
| 5 | Manf. test jumper | 1=not installed |
| 4 | System RAM | 0=512K, 1=256K |
| 0-3 | - | - |
|
| 61h |
| bit | význam |
|---|
| 7 | Parity Check |
| 6 | Channel Check |
| 5 | Timer Output bit 2 state |
| 4 | Refresh Detect |
| 3 | Enable I/O check |
| 2 | Enable RAM Parity Check |
| 1 | Speaker Data |
| 0 | Speaker Timer 2 Gate |
|
| 62h |
AT Keyboard Input Port
| bit | význam |
|---|
| 7 | Keyboard data output |
| 6 | Keyboard clock output |
| 5 | Input buffer empty |
| 4 | Output buffer full |
| 3 | - |
| 2 | - |
| 1 | Gate A20 |
| 0 | System reset |
|
| 63h | ? |
| 64h |
AT Keyboard Status Register
| bit | význam | hodnoty |
|---|
| 7 | Parity Error | 1=even parity, 0=odd parity (no error) |
| 6 | Receive Timeout | 1=keyboard did not finish |
| 5 | Transmit Timeout | 1=keyboard did not finish |
| 4 | Inhibit switch | 1=keyboard NOT inhibited |
| 3 | Command/data | 1=addressed as port 64h, 0=port 60h |
| 2 | System flag | 1=Self test OK, 0=reset by power on |
| 1 | Input buffer full | - |
| 0 | Output buffer full | - |
|
| 65h - 6Fh | ? |
| 65h - 6Fh | ? |
| Porty | Význam |
|---|
| 0C0h | Channel 4 Base and Current Address Register |
| 0C2h | Channel 4 Base and Current Word Count |
| 0C4h | Channel 5 Base and Current Address Register |
| 0C6h | Channel 5 Base and Current Word Count |
| 0C8h | Channel 6 Base and Current Address Register |
| 0CAh | Channel 6 Base and Current Word Count |
| 0CCh | Channel 7 Base and Current Address Register |
| 0CEh | Channel 7 Base and Current Word Count |
| 0D0h | Read Status Register/Write Command Register |
| 0D2h | Write Request Register |
| 0D4h | Write Single Mask Register Bit |
| 0D6h | Write Mode Register |
| 0D8h | Clear Byte Pointer Flip-flop |
| 0DAh | Read Temporary Register/Write Master Clear |
| 0DCh | Clear Mask Register |
| 0DEh | Write All Mask Register Bits |