path: root/src/mame/drivers/victor9k.cpp
diff options
authorGravatarGravatar Vas Crabb <>2018-07-07 02:40:29 +1000
committerGravatarGravatar Vas Crabb <>2018-07-07 02:40:29 +1000
commitc3fb11c2c98a5c28ece6a27093a0f9def350ac64 (patch)
treec68b38f05ed1d32358add721fda7f45e8803479f /src/mame/drivers/victor9k.cpp
parent5d9e33b786d7ef452317439359f3cbd8cc920513 (diff)
There are multiple issues with the current device callbacks: * They always dispatch through a pointer-to-member * Chained callbacks are a linked list so the branch unit can't predict the early * There's a runtime decision made on the left/right shift direction * There are runtime NULL checks on various objects * Binding a lambda isn't practical * Arbitrary transformations are not supported * When chaining callbacks it isn't clear what the MCFG_DEVCB_ modifiers apply to * It isn't possible to just append to a callback in derived configuration * The macros need a magic, hidden local called devcb * Moving code that uses the magic locals around is error-prone * Writing the MCFG_ macros to make a device usable is a pain * You can't discover applicable MCFG_ macros with intellisense * Macros are not scoped * Using an inappropriate macro isn't detected at compile time * Lots of other things This changeset overcomes the biggest obstacle to remving MCFG_ macros altogether. Essentially, to allow a devcb to be configured, call .bind() and expose the result (a bind target for the callback). Bind target methods starting with "set" repace the current callbacks; methods starting with "append" append to them. You can't reconfigure a callback after resolving it. There's no need to use a macro matching the handler signatures - use FUNC for everything. Current device is implied if no tag/finder is supplied (no need for explicit this). Lambdas are supported, and the memory space and offset are optional. These kinds of things work: * .read_cb().set([this] () { return something; }); * .read_cb().set([this] (offs_t offset) { return ~offset; }); * .write_cb().set([this] (offs_t offset, u8 data) { m_array[offset] = data; }); * .write_cb().set([this] (int state) { some_var = state; }); Arbitrary transforms are allowed, and they can modify offset/mask for example: * .read_cb().set(FUNC(my_state::handler)).transform([] (u8 data) { return bitswap<4>(data, 1, 3, 0, 2); }); * .read_cb().set(m_dev, FUNC(some_device::member)).transform([] (offs_t &offset, u8 data) { offset ^= 3; return data; }); It's possible to stack arbitrary transforms, at the cost of compile time (the whole transform stack gets inlined at compile time). Shifts count as an arbitrary transform, but mask/exor does not. Order of mask/shift/exor now matters. Modifications are applied in the specified order. These are NOT EQUIVALENT: * .read_cb().set(FUNC(my_state::handler)).mask(0x06).lshift(2); * .read_cb().set(FUNC(my_state::handler)).lshift(2).mask(0x06); The bit helper no longer reverses its behaviour for read callbacks, and I/O ports are no longer aware of the field mask. Binding a read callback to no-op is not supported - specify a constant. The GND and VCC aliases have been removed intentionally - they're TTL-centric, and were already being abused. Other quirks have been preserved, including write logger only logging when the data is non-zero (quite unhelpful in many of the cases where it's used). Legacy syntax is still supported for simple cases, but will be phased out. New devices should not have MCFG_ macros. I don't think I've missed any fundamental issues, but if I've broken something, let me know.
Diffstat (limited to 'src/mame/drivers/victor9k.cpp')
1 files changed, 5 insertions, 6 deletions
diff --git a/src/mame/drivers/victor9k.cpp b/src/mame/drivers/victor9k.cpp
index c048e2e2e21..9ad6d577c79 100644
--- a/src/mame/drivers/victor9k.cpp
+++ b/src/mame/drivers/victor9k.cpp
@@ -60,7 +60,6 @@
#define RS232_B_TAG "rs232b"
#define SCREEN_TAG "screen"
#define KB_TAG "kb"
-#define FDC_TAG "fdc"
class victor9k_state : public driver_device
@@ -79,7 +78,7 @@ public:
m_crtc(*this, HD46505S_TAG),
m_ram(*this, RAM_TAG),
m_kb(*this, KB_TAG),
- m_fdc(*this, FDC_TAG),
+ m_fdc(*this, "fdc"),
m_centronics(*this, "centronics"),
m_rs232a(*this, RS232_A_TAG),
m_rs232b(*this, RS232_B_TAG),
@@ -783,10 +782,10 @@ MACHINE_CONFIG_START(victor9k_state::victor9k)
MCFG_VICTOR9K_KBRDY_HANDLER(WRITELINE(*this, victor9k_state, kbrdy_w))
MCFG_VICTOR9K_KBDATA_HANDLER(WRITELINE(*this, victor9k_state, kbdata_w))
- MCFG_VICTOR_9000_FDC_IRQ_CB(WRITELINE(*this, victor9k_state, fdc_irq_w))
- MCFG_VICTOR_9000_FDC_SYN_CB(WRITELINE(I8259A_TAG, pic8259_device, ir0_w)) MCFG_DEVCB_XOR(1)
+ VICTOR_9000_FDC(config, m_fdc, 0);
+ m_fdc->irq_wr_callback().set(FUNC(victor9k_state::fdc_irq_w));
+ m_fdc->syn_wr_callback().set(I8259A_TAG, FUNC(pic8259_device::ir0_w)).invert();
+ m_fdc->lbrdy_wr_callback().set_inputline(I8088_TAG, INPUT_LINE_TEST).invert();
// internal ram