Joypad: Difference between revisions
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Joypads have 4 directions and 4 buttons contacts. | |||
Registers used to read the button's states directly: | Registers used to read the button's states directly (all bits are active low): | ||
*REG_P1CNT ($300000), | *'''REG_P1CNT''' ($300000), Player 1: | ||
*REG_P2CNT ($340000), | *'''REG_P2CNT''' ($340000), Player 2: | ||
*REG_STATUS_B ($380000), | {{8BitRegister|D|1|C|1|B|1|A|1|Right|1|Left|1|Up|1|Down|1}} | ||
*'''REG_STATUS_B''' ($380000), SELECTs and STARTs: | |||
{{8BitRegister|-|4|P2 Select|1|P2 Start|1|P1 Select|1|P2 Start|1}} | |||
The '''BIOSF_VBL''' ($C0044A) [[BIOS calls|BIOS call]] can be used to read joypads more easily: it sets values in the BIOS's RAM space which gives currently pressed, state change, and "repeat" values for both joypads. Need details... | |||
[[Category: controllers]] | [[Category: controllers]] | ||
Revision as of 06:00, 8 March 2011
Joypads have 4 directions and 4 buttons contacts.
Registers used to read the button's states directly (all bits are active low):
- REG_P1CNT ($300000), Player 1:
- REG_P2CNT ($340000), Player 2:
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| Def | D | C | B | A | Right | Left | Up | Down |
- REG_STATUS_B ($380000), SELECTs and STARTs:
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| Def | - | P2 Select | P2 Start | P1 Select | P2 Start | |||
The BIOSF_VBL ($C0044A) BIOS call can be used to read joypads more easily: it sets values in the BIOS's RAM space which gives currently pressed, state change, and "repeat" values for both joypads. Need details...