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Declare no tube, optimistically watch for characters.

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This commit is contained in:
Thomas Harte
2025-09-16 16:25:41 -04:00
parent 1e90387198
commit 019526332d
1 changed files with 22 additions and 7 deletions
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Machines/Acorn/BBCMicro/BBCMicro.cpp
+22 -7
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@@ -105,6 +105,8 @@ struct SystemVIAPortHandler: public MOS::MOS6522::IRQDelegatePortHandler {
// B0: enable writes to the sound generator;
// B1, B2: read/write to the sound processor;
// B3: enable writes to the keyboard.
// B4/B5: "hardware scrolling" (new base address > 32768?)
// B6/B7: keyboard LEDs.
const auto mask = uint8_t(1 << (value & 7));
const auto old_latch = latch_;
latch_ = (latch_ & ~mask) | ((value & 8) ? mask : 0);
@@ -113,7 +115,11 @@ struct SystemVIAPortHandler: public MOS::MOS6522::IRQDelegatePortHandler {
if((old_latch^latch_) & old_latch & 1) {
audio_->write(port_a_output_);
}
// Logger::info().append("Programmable latch: %d%d%d%d", bool(latch_ & 8), bool(latch_ & 4), bool(latch_ & 2), bool(latch_ & 1));
// Update keyboard LEDs.
if(mask >= 0x40) {
Logger::info().append("CAPS: %d SHIFT: %d", bool(latch_ & 0x40), bool(latch_ & 0x40));
}
}
template <MOS::MOS6522::Port port>
@@ -125,7 +131,7 @@ struct SystemVIAPortHandler: public MOS::MOS6522::IRQDelegatePortHandler {
// b6/7: speech interrupt/ready inputs.
Logger::info().append("Port B read");
return 0xff;
return 0x3f; // b6 = b7 = 0 => no speech hardware?
}
if(latch_ & 0b1000) {
@@ -135,13 +141,11 @@ struct SystemVIAPortHandler: public MOS::MOS6522::IRQDelegatePortHandler {
// Read keyboard. Low six bits of output are key to check, state should be returned in high bit.
// Logger::info().append("Keyboard read from line %d", port_a_output_);
switch(port_a_output_ & 0x7f) {
default: return 0xff; // Default: key not pressed.
default: return 0x80; // Default: key not pressed.
case 9: return 0x00; //
case 8: return 0x00; // Startup mode. (= mode 7?)
case 7: return 0x00; //
case 6: return 0xff; // Boot from network?
}
}
@@ -185,8 +189,9 @@ public:
// bool print = false;
// uint16_t start_address = 0x7c00;
// int rows = 24;
// if(print) {
// for(int y = 0; y < 24; y++) {
// for(int y = 0; y < rows; y++) {
// for(int x = 0; x < 40; x++) {
// printf("%c", ram_[start_address + y*40 + x]);
// }
@@ -501,8 +506,14 @@ public:
break;
}
}
} else if(address == 0xfee0) {
if(is_read(operation)) {
Logger::info().append("Read tube status: 0");
*value = 0;
} else {
Logger::info().append("Wrote tube: %02x", *value);
}
}
else {
Logger::error()
.append("Unhandled IO %s at %04x", is_read(operation) ? "read" : "write", address)
@@ -524,6 +535,10 @@ public:
} else {
if(memory_write_masks_[address >> 14]) {
memory_[address >> 14][address] = *value;
if(address >= 0x7c00 && *value) {
Logger::info().append("Output character: %c", *value);
}
}
}