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Wires up the final IWM signal, SEL, preparatory to an implementation.

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This commit is contained in:
Thomas Harte 2019-05-30 12:08:00 -04:00
parent b3d2b4cd37
commit 4632be4fe5
3 changed files with 38 additions and 9 deletions
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7
Components/DiskII/IWM.cpp
View File

@ -19,7 +19,7 @@ IWM::IWM(int clock_rate) {
uint8_t IWM::read(int address) {
access(address);
// printf("IWM r %d (%02x)\n", address&0xf, q_switches_);
printf("IWM r %d (%02x)\n", address&0xf, q_switches_);
switch(q_switches_) {
default: return 0x00; // Undefined.
@ -38,6 +38,7 @@ uint8_t IWM::read(int address) {
void IWM::write(int address, uint8_t input) {
access(address);
printf("IWM w %d (%02x)\n", address&0xf);
switch(q_switches_) {
default:
break;
@ -68,3 +69,7 @@ void IWM::access(int address) {
void IWM::run_for(const Cycles cycles) {
}
void IWM::set_select(bool enabled) {
printf("IWM s %d\n", int(enabled));
}

5
Components/DiskII/IWM.hpp
View File

@ -29,6 +29,11 @@ class IWM {
*/
uint8_t read(int address);
/*!
Sets the current input of the IWM's SEL line.
*/
void set_select(bool enabled);
/// Advances the controller by @c cycles.
void run_for(const Cycles cycles);

35
Machines/Apple/Macintosh/Macintosh.cpp
View File

@ -42,7 +42,7 @@ class ConcreteMachine:
mc68000_(*this),
video_(ram_.data()),
via_(via_port_handler_),
via_port_handler_(*this, clock_, keyboard_, video_),
via_port_handler_(*this, clock_, keyboard_, video_, iwm_),
iwm_(CLOCK_RATE) {
// Grab a copy of the ROM and convert it into big-endian data.
@ -73,7 +73,7 @@ class ConcreteMachine:
HalfCycles perform_bus_operation(const Microcycle &cycle, int is_supervisor) {
// time_since_video_update_ += cycle.length;
time_since_iwm_update_ += cycle.length;
iwm_.time_since_update += cycle.length;
// The VIA runs at one-tenth of the 68000's clock speed, in sync with the E clock.
// See: Guide to the Macintosh Hardware Family p149 (PDF p188).
@ -135,12 +135,12 @@ class ConcreteMachine:
case 0x68f000:
// The IWM; this is a purely polled device, so can be run on demand.
iwm_.run_for(time_since_iwm_update_.flush_cycles());
iwm_.flush();
if(cycle.operation & Microcycle::Read) {
cycle.value->halves.low = iwm_.read(register_address);
cycle.value->halves.low = iwm_.iwm.read(register_address);
if(cycle.operation & Microcycle::SelectWord) cycle.value->halves.high = 0xff;
} else {
iwm_.write(register_address, cycle.value->halves.low);
iwm_.iwm.write(register_address, cycle.value->halves.low);
}
break;
@ -239,10 +239,21 @@ class ConcreteMachine:
}
private:
struct IWM {
IWM(int clock_rate) : iwm(clock_rate) {}
Apple::IWM iwm;
HalfCycles time_since_update;
void flush() {
iwm.run_for(time_since_update.flush_cycles());
}
};
class VIAPortHandler: public MOS::MOS6522::PortHandler {
public:
VIAPortHandler(ConcreteMachine &machine, RealTimeClock &clock, Keyboard &keyboard, Video &video) :
machine_(machine), clock_(clock), keyboard_(keyboard), video_(video) {}
VIAPortHandler(ConcreteMachine &machine, RealTimeClock &clock, Keyboard &keyboard, Video &video, IWM &iwm) :
machine_(machine), clock_(clock), keyboard_(keyboard), video_(video), iwm_(iwm) {}
using Port = MOS::MOS6522::Port;
using Line = MOS::MOS6522::Line;
@ -265,8 +276,13 @@ class ConcreteMachine:
*/
// printf("6522 A: %02x\n", value);
iwm_.flush();
iwm_.iwm.set_select(!(value & 0x20));
machine_.set_use_alternate_screen_buffer(!(value & 0x40));
machine_.set_rom_is_overlay(!!(value & 0x10));
// TODO: alternate sound buffer, and audio output volume.
break;
case Port::B:
@ -283,6 +299,8 @@ class ConcreteMachine:
*/
if(value & 0x4) clock_.abort();
else clock_.set_input(!!(value & 0x2), !!(value & 0x1));
// TODO: sound enabled/disabled.
break;
}
}
@ -318,6 +336,7 @@ class ConcreteMachine:
RealTimeClock &clock_;
Keyboard &keyboard_;
Video &video_;
IWM &iwm_;
};
std::array<uint16_t, 32*1024> rom_;
@ -332,7 +351,7 @@ class ConcreteMachine:
MOS::MOS6522::MOS6522<VIAPortHandler> via_;
VIAPortHandler via_port_handler_;
Apple::IWM iwm_;
IWM iwm_;
HalfCycles via_clock_;
HalfCycles real_time_clock_;