CONTROLLER SETUP: Difference between revisions
(Created page with "== CONTROLLER_SETUP ($C004D4): sets up controllers == '''Warning:''' register contents aren't preserved! Used registers varies. Detects controllers configuration and sets in...") |
m (small changes) |
||
| (One intermediate revision by one other user not shown) | |||
| Line 5: | Line 5: | ||
Detects controllers configuration and sets inputs status byte accordingly. | Detects controllers configuration and sets inputs status byte accordingly. | ||
Range of | Range of supported devices and detection method varies depending on system type and System ROM revision. | ||
== Status bytes == | == Status bytes == | ||
Status byte is the first byte of the input register into BIOS RAM (ex. {{BR|BIOS_P1STATUS}} for P1). It is used by [[SYSTEM_IO]] to correctly read devices. | |||
Status byte is the first byte of the input register into | |||
Possible values are: | Possible values are: | ||
| Line 21: | Line 20: | ||
== MVS == | == MVS == | ||
MVS setup is very straightforward: if hard dip 3 is set, | MVS setup is very straightforward: if hard dip 3 is set, BIOS_P1STATUS is set to 3, else status byte is set to 0 for all players. | ||
== NEO•GEO / NEO•GEO CD== | == NEO•GEO / NEO•GEO CD== | ||
| Line 27: | Line 26: | ||
NEO•GEO controller setup is much more elaborate, looking for 6 different devices. (standard controller, mahjong, 4P adapter, keyboard, plus 2 unknown devices) | NEO•GEO controller setup is much more elaborate, looking for 6 different devices. (standard controller, mahjong, 4P adapter, keyboard, plus 2 unknown devices) | ||
The bios writes various configurations on controller outputs, then checks back controller status (for example a standard | The bios writes various configurations on controller outputs, then checks back controller status (for example a standard controller returns button D pressed when OUT3 is set to 1). Checked button can be either D/C/Select/Start. | ||
Resulting status bytes are stored into a preset table: | Resulting status bytes are stored into a preset table: | ||
| Line 112: | Line 111: | ||
*All status bytes are decreased between 4th & 5th step. | *All status bytes are decreased between 4th & 5th step. | ||
*Keep in mind there's an inverter between outputs and controller ports, writing 101 in the output register actually outputs 010 on the port. | *Keep in mind there's an inverter between outputs and controller ports, writing 101 in the output register actually outputs 010 on the port. | ||
[[Category:BIOS calls]] | [[Category:BIOS calls]] | ||
Latest revision as of 11:01, 19 January 2016
CONTROLLER_SETUP ($C004D4): sets up controllers
Warning: register contents aren't preserved! Used registers varies.
Detects controllers configuration and sets inputs status byte accordingly.
Range of supported devices and detection method varies depending on system type and System ROM revision.
Status bytes
Status byte is the first byte of the input register into BIOS RAM (ex. BIOS_P1STATUS ( $10FD94) for P1). It is used by SYSTEM_IO to correctly read devices.
Possible values are:
- 0 - No connection (dealt as standard controller)
- 1 - Standard controller
- 2 - Expanded controller (4P mode)
- 3 - Mahjong controller
- 4 - Keyboard
MVS
MVS setup is very straightforward: if hard dip 3 is set, BIOS_P1STATUS is set to 3, else status byte is set to 0 for all players.
NEO•GEO / NEO•GEO CD
NEO•GEO controller setup is much more elaborate, looking for 6 different devices. (standard controller, mahjong, 4P adapter, keyboard, plus 2 unknown devices)
The bios writes various configurations on controller outputs, then checks back controller status (for example a standard controller returns button D pressed when OUT3 is set to 1). Checked button can be either D/C/Select/Start.
Resulting status bytes are stored into a preset table:
(neo-epo bios) C16A44: 02 02 00 00, 00 02 00 00, 02 00 00 00, 00 00 00 00 C16A54: 00 00 00 00, 01 00 01 00, 00 01 00 01, 01 01 01 01 C16A64: 03 03 00 00, 00 03 00 00, 03 00 00 00, 00 00 00 00 C16A74: 01 01 03 03, 01 01 01 03, 01 01 03 01, 01 01 01 01 C16A84: 03 03 00 00, 00 03 00 00, 03 00 00 00, 00 00 00 00 C16A94: 04 04 00 00, 00 04 00 00, 04 00 00 00, 00 00 00 00
Software runs 6 consecutive checks. All of then are done, regardless if a previous device does match or not, however a status byte isn't overwritten if not 0.
This means 1st check has top priority, 6th has lowest.
Output status, checked button and resulting status bytes (P1-4) are:
| outputs config (binary) | button checked | P1 & P2 match | P2 match | P1 match | no match | tested device | |
| 1st check | 100 100 | D | 02 02 00 00 | 00 02 00 00 | 02 00 00 00 | 00 00 00 00 | standard controller |
| 2nd check | 001 001, then 101 101 | C | 00 00 00 00 | 01 00 01 00 | 00 01 00 01 | 01 01 01 01 | unknown device |
| 3rd check | 011 011, then 111 111 | D | 03 03 00 00 | 00 03 00 00 | 03 00 00 00 | 00 00 00 00 | unknown device |
| 4th check | 110 110 | D | 01 01 03 03 | 01 01 01 03 | 01 01 03 01 | 01 01 01 01 | early 4P adapter ? |
| 5th check | 100 100 | SELECT | 03 03 00 00 | 00 03 00 00 | 03 00 00 00 | 00 00 00 00 | Mahjong controller |
| 6th check | 100 100 | START | 04 04 00 00 | 00 04 00 00 | 04 00 00 00 | 00 00 00 00 | Keyboard |
- All status bytes are decreased between 4th & 5th step.
- Keep in mind there's an inverter between outputs and controller ports, writing 101 in the output register actually outputs 010 on the port.