diff options
Diffstat (limited to 'src/emu/bus/nes_ctrl/ctrl.c')
| -rw-r--r-- | src/emu/bus/nes_ctrl/ctrl.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/src/emu/bus/nes_ctrl/ctrl.c b/src/emu/bus/nes_ctrl/ctrl.c index c90b2bf82e5..9e81d228f6a 100644 --- a/src/emu/bus/nes_ctrl/ctrl.c +++ b/src/emu/bus/nes_ctrl/ctrl.c @@ -1,6 +1,6 @@ /********************************************************************** - Nintendo Family Computer & Entertainment System controller ports + Nintendo Family Computer & Entertainment System controller ports and Family Computer expansion port emulation Here we emulate in fact 3 different kind of ports, which are @@ -9,15 +9,15 @@ corresponding address ($4016 for port1, $4017 for port2) - FC controller ports: these are only hooked to bit 0 of the corresponding address (so that e.g. a NES Zapper could not - be connected to a later FC AV model, because its inputs + be connected to a later FC AV model, because its inputs would not be detected) - FC expansion port: this is hooked to bits 0-4 of both addresses To make things a little bit more complex, old FC models have the controller hardwired to the unit, and the P2 controllers are - directly hooked also to one of the expansion port lines (namely, + directly hooked also to one of the expansion port lines (namely, microphone inputs from P2 go to $4016 bit 2) - Even if the controller port and the expansion port are + Even if the controller port and the expansion port are physically different (the FC expansion is a 15pin port, while the controller ports are 7pin), we emulate them as variants of a common device, exposing the following handlers: @@ -25,15 +25,15 @@ inputs from controllers - read_bit34: for bit3,4 reading, expected to be at the correct offset (but we don't currently check for read_bit34 & 0xf8==0) - - read_exp: for reads going through the expansion, with a offset + - read_exp: for reads going through the expansion, with a offset parameter to decide whether we are reading from $4016 and $4017 - write: to acknowledge writes to $4016 - The driver emulation will take care to only call the correct - handlers they have hooks for: Basic usage is that the expansion - port calls read_exp, FC ctrl ports call read_bit0, and NES ctrl - ports call both read_bit0 and read_bit34. However, to cope with - the original FC microphone, we will have the second controller + The driver emulation will take care to only call the correct + handlers they have hooks for: Basic usage is that the expansion + port calls read_exp, FC ctrl ports call read_bit0, and NES ctrl + ports call both read_bit0 and read_bit34. However, to cope with + the original FC microphone, we will have the second controller port calling read_exp too. Copyright MESS Team. @@ -168,7 +168,7 @@ SLOT_INTERFACE_START( nes_control_port1_devices ) SLOT_INTERFACE("joypad", NES_JOYPAD) SLOT_INTERFACE("zapper", NES_ZAPPER) SLOT_INTERFACE("4score_p1p3", NES_4SCORE_P1P3) -// SLOT_INTERFACE("miracle_piano", NES_MIRACLE) +// SLOT_INTERFACE("miracle_piano", NES_MIRACLE) SLOT_INTERFACE_END SLOT_INTERFACE_START( nes_control_port2_devices ) |
