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mirror of https://github.com/TomHarte/CLK.git synced 2024-12-27 01:31:42 +00:00

Adds in VIA access decoding, and a note to self on video.

The Mac now proceeds to try to talk to the IWM.
This commit is contained in:
Thomas Harte 2019-05-04 14:23:37 -04:00
parent 29fc024ecd
commit bc9eb82e6f
2 changed files with 28 additions and 3 deletions

View File

@ -73,12 +73,33 @@ class ConcreteMachine:
// Hardware devices begin at 0x800000.
mc68000_.set_is_peripheral_address(word_address >= 0x400000);
if(word_address >= 0x400000) {
printf("IO access to %06x\n", word_address << 1);
if(cycle.data_select_active()) {
printf("IO access to %06x: ", word_address << 1);
// VIA accesses are via address 0xefe1fe + register*512,
// which at word precision is 0x77f0ff + register*256.
if((word_address & 0x77f0ff) == 0x77f0ff) {
printf("VIA access ");
if(cycle.operation & Microcycle::Read) {
cycle.value->halves.low = via_.get_register(word_address >> 8);
if(cycle.operation & Microcycle::SelectWord) cycle.value->halves.high = 0xff;
} else {
via_.set_register(word_address >> 8, cycle.value->halves.low);
}
}
printf("\n");
}
} else {
if(cycle.data_select_active()) {
uint16_t *memory_base = nullptr;
bool is_read_only = false;
if(word_address & 0x200000 || ROM_is_overlay_) {
// When ROM overlay is enabled, the ROM begins at both $000000 and $400000,
// and RAM is available at $600000.
//
// Otherwise RAM is mapped at $000000 and ROM from $400000.
if((ROM_is_overlay_ && word_address < 0x600000) || (!ROM_is_overlay_ && word_address & 0x200000)) {
memory_base = rom_.data();
word_address %= rom_.size();
is_read_only = true;
@ -143,7 +164,7 @@ class ConcreteMachine:
*/
private:
class VIAPortHandler: public MOS::MOS6522::PortHandler {
struct VIAPortHandler: public MOS::MOS6522::PortHandler {
void set_port_output(MOS::MOS6522::Port port, uint8_t value, uint8_t direction_mask) {
/*
Port A:

View File

@ -28,3 +28,7 @@ Video::Video(uint16_t *ram) :
void Video::set_scan_target(Outputs::Display::ScanTarget *scan_target) {
crt_.set_scan_target(scan_target);
}
/*
Video: $1A700 and the alternate buffer starts at $12700; for a 512K Macintosh, add $60000 to these numbers.
*/