x68000:joystick_regs
Table of Contents
Joystick Registers
The X68000 joystick interface is a µPD82C55. The ADPCM sample rate and pan pot are also set through Port C of this device.
Register List
| Address | Size | R/W | Description |
|---|---|---|---|
| 0xE9A001 | 1.b | R | 8255 Port A (Joystick #1) |
| 0xE9A003 | 1.b | R | 8255 Port B (Joystick #2) |
| 0xE9A005 | 1.b | R/w | 8255 Port C (Joystick Control) |
| 0xE9A007 | 1.b | W | 8255 Control Word (Mode/Bit Manipulation) |
Register Descriptions
Joystick # 1 (0xE9A001):
Joystick # 2 (0xE9A003):
| MSX 2 Button |
|---|
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|---|---|---|---|---|---|---|---|
| 0 | TRG B | TRG A | 0 | RIGHT | LEFT | BACK | FORWARD |
| CPSF and CPSF-MD |
|---|
PC4/PC5 = 0:
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|---|---|---|---|---|---|---|---|
| 0 | TRG B | TRG A | 0 | RIGHT | LEFT | BACK | FORWARD |
PC4/PC5 = 1:
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|---|---|---|---|---|---|---|---|
| 0 | START | TRG C | 0 | MODE | TRG X | TRG Y | TRG Z |
—
Joystick Control (0xE9A005):
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|---|---|---|---|---|---|---|---|
| IOC7 | IOC6 | IOC5 | IOC4 | Sampling Rate | PCM PAN | ||
| Bits | Name | Description |
|---|---|---|
| 7 | IOC7 | %0: Normal operation %1: Joystick #1 Option Function B |
| 6 | IOC6 | %0: Normal operation %1: Joystick #1 Option Function A |
| 5 | IOC5 | %0: Normal operation %1: Joystick #2 Disable processing |
| 4 | IOC4 | %0: Normal operation %1: Joystick #1 Disable processing |
| 3~2 | Sampling Rate | ADPCM sampling frequency setting |
| 1~0 | PCM PAN | ADPCM output pan setting |
—
Control Word - Bit Set/Reset (0xE9A007):
* Note: When MSB of this register is '0' the function is 8255 Port C line set/reset.
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|---|---|---|---|---|---|---|---|
| 0 | BITSEL | DATA | |||||
| Bits | Name | Description |
|---|---|---|
| 3~1 | BITSEL | Specify the position to manipulate. Values 0~7 correspond to its respective PCn line on the 8255. |
| 0 | DATA | Value to set |
—
Control Word - Mode (0xE9A007):
* Note: When MSB of this register is '1' the function is 8255 mode setting.
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|---|---|---|---|---|---|---|---|
| 1 | Group A Mode | PORT A IN/OUT | PORT C(High) IN/OUT | Group B Mode | PORT B IN/OUT | PORT C(low) IN/OUT | |
| Bits | Name | Description |
|---|---|---|
| 6~5 | Group A Mode | Operating mode of group A(Port A and Port C(High)) %00: Mode 0 %01: Mode 1 %10: Mode 2 %11: Mode 3 |
| 4 | PORT A IN/OUT | %0: Port A Output %1: Port A Input |
| 3 | PORT C(High) IN/OUT | %0: Port C(High) Output %1: Port C(High) Input |
| 2 | Group B Mode | Operating mode of Group B(Port B and Port C(Low)) %0: Mode 0 %1: Mode 1 |
| 1 | PORT B IN/OUT | %0: Port B Output %1: Port B Input |
| 0 | PORT C(Low) IN/OUT | %0: Port C(Low) Output %1: Port C(Low) Input |
x68000/joystick_regs.txt · Last modified: by 127.0.0.1