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Attempts retroactively to enforce the rule that 8-bit index modes => no top byte.

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(Rather than a preserved but ignored top byte)
This commit is contained in:
Thomas Harte 2020-11-02 18:55:28 -05:00
parent 53f60f7c87
commit 0178aaee2b
3 changed files with 146 additions and 35 deletions
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159
Machines/Apple/AppleIIgs/AppleIIgs.cpp
View File

@ -98,6 +98,7 @@ class ConcreteMachine:
forceinline Cycles perform_bus_operation(const CPU::WDC65816::BusOperation operation, const uint32_t address, uint8_t *const value) {
const auto &region = MemoryMapRegion(memory_, address);
static bool log = false;
// TODO: potentially push time to clock_.
@ -106,7 +107,8 @@ class ConcreteMachine:
const bool is_read = isReadOperation(operation);
memory_.access(uint16_t(address), is_read);
switch(address & 0xffff) {
const auto address_suffix = address & 0xffff;
switch(address_suffix) {
// New video register.
case 0xc029:
@ -193,7 +195,7 @@ class ConcreteMachine:
#undef LanguageRead
#undef SwitchRead
// Video switches.
// Video switches (and annunciators).
case 0xc050: case 0xc051:
video_.set_text(address & 1);
break;
@ -206,6 +208,11 @@ class ConcreteMachine:
case 0xc056: case 0xc057:
video_.set_high_resolution(address&1);
break;
case 0xc058: case 0xc059:
case 0xc05a: case 0xc05b:
case 0xc05c: case 0xc05d:
// Annunciators 0, 1 and 2.
break;
case 0xc05e: case 0xc05f:
video_.set_annunciator_3(!(address&1));
break;
@ -271,19 +278,105 @@ class ConcreteMachine:
case 0xc071: case 0xc072: case 0xc073: case 0xc074: case 0xc075: case 0xc076: case 0xc077:
case 0xc078: case 0xc079: case 0xc07a: case 0xc07b: case 0xc07c: case 0xc07d: case 0xc07e: case 0xc07f:
if(is_read) {
*value = rom_[rom_.size() - 65536 + (address & 0xffff)];
*value = rom_[rom_.size() - 65536 + address_suffix];
}
break;
// Analogue inputs. All TODO.
case 0xc060: case 0xc061: case 0xc062: case 0xc063:
// Joystick buttons (and keyboard modifiers).
if(is_read) {
*value = 0x00;
}
break;
case 0xc064: case 0xc065: case 0xc066: case 0xc067:
// Analogue inputs.
if(is_read) {
*value = 0x00;
}
break;
case 0xc070:
// TODO: begin analogue channel charge.
break;
case 0xc02d:
// TODO: slot register selection.
// b7: 0 = internal ROM code for slot 7;
// b6: 0 = internal ROM code for slot 6;
// b5: 0 = internal ROM code for slot 5;
// b4: 0 = internal ROM code for slot 4;
// b3: reserved;
// b2: internal ROM code for slot 2;
// b1: internal ROM code for slot 1;
// b0: reserved.
if(is_read) {
*value = card_mask_;
} else {
card_mask_ = *value;
}
break;
// Addresses that seemingly map to nothing; provided as a separate break out for now,
// while I have an assert on unknown reads.
case 0xc049: case 0xc04a: case 0xc04b: case 0xc04c: case 0xc04d: case 0xc04e: case 0xc04f:
case 0xc069: case 0xc06a: case 0xc06b: case 0xc06c:
printf("Ignoring %04x\n", address_suffix);
log = true;
break;
// 'Test Mode', whatever that is (?)
case 0xc06e: case 0xc06f:
test_mode_ = address & 1;
break;
case 0xc06d:
if(is_read) {
*value = test_mode_ * 0x80;
}
break;
default:
if((address & 0xffff) < 0xc100) {
// TODO: all other IO accesses.
printf("Unhandled IO: %04x\n", address & 0xffff);
assert(false);
// Check for a card access.
if(address_suffix >= 0xc080 && address_suffix < 0xc800) {
// This is an abridged version of the similar code in AppleII.cpp from
// line 653; it would be good to factor that out and support cards here.
// For now just either supply the internal ROM or nothing as per the
// current card mask.
size_t card_number = 0;
if(address >= 0xc100) {
/*
Decode the area conventionally used by cards for ROMs:
0xCn00 to 0xCnff: card n.
*/
card_number = (address - 0xc000) >> 8;
} else {
/*
Decode the area conventionally used by cards for registers:
C0n0 to C0nF: card n - 8.
*/
card_number = (address - 0xc080) >> 4;
}
const uint8_t permitted_card_mask_ = card_mask_ & 0xf6;
if(permitted_card_mask_ & (1 << card_number)) {
// TODO: Access an actual card.
if(is_read) {
*value = 0xff;
}
} else {
// TODO: disk-port soft switches should be in COEx.
printf("Internal card-area access: %04x\n", address_suffix);
if(is_read) {
*value = rom_[rom_.size() - 65536 + address_suffix];
}
}
} else {
// Card IO. Not implemented!
if(isReadOperation(operation)) {
*value = 0xff;
if(address_suffix < 0xc080) {
// TODO: all other IO accesses.
printf("Unhandled IO: %04x\n", address_suffix);
assert(false);
}
}
}
@ -299,20 +392,23 @@ class ConcreteMachine:
}
}
// printf("%06x %s %02x", address, isReadOperation(operation) ? "->" : "<-", *value);
// if(operation == CPU::WDC65816::BusOperation::ReadOpcode) {
// printf(" a:%04x x:%04x y:%04x s:%04x e:%d p:%02x db:%02x pb:%02x d:%04x\n",
// m65816_.get_value_of_register(CPU::WDC65816::Register::A),
// m65816_.get_value_of_register(CPU::WDC65816::Register::X),
// m65816_.get_value_of_register(CPU::WDC65816::Register::Y),
// m65816_.get_value_of_register(CPU::WDC65816::Register::StackPointer),
// m65816_.get_value_of_register(CPU::WDC65816::Register::EmulationFlag),
// m65816_.get_value_of_register(CPU::WDC65816::Register::Flags),
// m65816_.get_value_of_register(CPU::WDC65816::Register::DataBank),
// m65816_.get_value_of_register(CPU::WDC65816::Register::ProgramBank),
// m65816_.get_value_of_register(CPU::WDC65816::Register::Direct)
// );
// } else printf("\n");
// log |= (address >= 0xffa6d9) && (address < 0xffa6ec);
if(log) {
printf("%06x %s %02x", address, isReadOperation(operation) ? "->" : "<-", *value);
if(operation == CPU::WDC65816::BusOperation::ReadOpcode) {
printf(" a:%04x x:%04x y:%04x s:%04x e:%d p:%02x db:%02x pb:%02x d:%04x\n",
m65816_.get_value_of_register(CPU::WDC65816::Register::A),
m65816_.get_value_of_register(CPU::WDC65816::Register::X),
m65816_.get_value_of_register(CPU::WDC65816::Register::Y),
m65816_.get_value_of_register(CPU::WDC65816::Register::StackPointer),
m65816_.get_value_of_register(CPU::WDC65816::Register::EmulationFlag),
m65816_.get_value_of_register(CPU::WDC65816::Register::Flags),
m65816_.get_value_of_register(CPU::WDC65816::Register::DataBank),
m65816_.get_value_of_register(CPU::WDC65816::Register::ProgramBank),
m65816_.get_value_of_register(CPU::WDC65816::Register::Direct)
);
} else printf("\n");
}
Cycles duration = Cycles(5);
@ -333,9 +429,7 @@ class ConcreteMachine:
CPU::WDC65816::Processor<ConcreteMachine, false> m65816_;
MemoryMap memory_;
Apple::Clock::ParallelClock clock_;
Apple::IIgs::Video::Video video_;
Apple::IIgs::ADB::GLU adb_glu_;
// MARK: - Timing.
int fast_access_phase_ = 0;
int slow_access_phase_ = 0;
@ -348,7 +442,18 @@ class ConcreteMachine:
std::vector<uint8_t> rom_;
// MARK: - Other components.
Apple::Clock::ParallelClock clock_;
Apple::IIgs::Video::Video video_;
Apple::IIgs::ADB::GLU adb_glu_;
Zilog::SCC::z8530 scc_;
// MARK: - Cards.
// TODO: most of cards.
uint8_t card_mask_ = 0x00;
bool test_mode_ = false;
};
}

2
Machines/Apple/AppleIIgs/MemoryMap.hpp
View File

@ -185,7 +185,7 @@ class MemoryMap {
const uint8_t diff = value ^ shadow_register_;
shadow_register_ = value;
if(diff & 0x40) { // IO/language-card inhibit
if(diff & 0x40) { // IO/language-card inhibit.
set_language_card_paging();
set_card_paging();
}

20
Processors/65816/Implementation/65816Storage.cpp
View File

@ -1097,7 +1097,6 @@ void ProcessorStorage::set_emulation_mode(bool enabled) {
if(enabled) {
set_m_x_flags(true, true);
registers_.x.halves.high = registers_.y.halves.high = 0;
registers_.e_masks[0] = 0xff00;
registers_.e_masks[1] = 0x00ff;
} else {
@ -1109,17 +1108,24 @@ void ProcessorStorage::set_emulation_mode(bool enabled) {
}
void ProcessorStorage::set_m_x_flags(bool m, bool x) {
// true/1 => 8bit for both flags.
registers_.mx_flags[0] = m;
registers_.mx_flags[1] = x;
// Reset the top byte of x and y if _exiting_ 8-bit mode.
// TODO: rationalise this sort of logic, both here and
// with regards to the stack pointer.
if(!x && registers_.mx_flags[1]) {
registers_.x.halves.high = registers_.y.halves.high = 0;
}
registers_.x_masks[0] = x ? 0xff00 : 0x0000;
registers_.x_masks[1] = x ? 0x00ff : 0xffff;
registers_.x_shift = x ? 0 : 8;
registers_.m_masks[0] = m ? 0xff00 : 0x0000;
registers_.m_masks[1] = m ? 0x00ff : 0xffff;
registers_.m_shift = m ? 0 : 8;
registers_.x_masks[0] = x ? 0xff00 : 0x0000;
registers_.x_masks[1] = x ? 0x00ff : 0xffff;
registers_.x_shift = x ? 0 : 8;
// true/1 => 8bit for both flags.
registers_.mx_flags[0] = m;
registers_.mx_flags[1] = x;
}
uint8_t ProcessorStorage::get_flags() const {