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mirror of https://github.com/TomHarte/CLK.git synced 2024-12-26 09:29:45 +00:00

Started on a real ugly-implementation coroutine approach, and implemented specify as a fairly trivial first command: it has no result phase, and is the only thing called by AMSDOS as part of the initialisation sequence.

This commit is contained in:
Thomas Harte 2017-08-06 12:36:18 -04:00
parent 77da582e88
commit 89f6de1383
2 changed files with 193 additions and 63 deletions

View File

@ -12,78 +12,41 @@
using namespace Intel;
namespace {
const uint8_t StatusRQM = 0x80; // Set indicates: ready to send or receive from processor.
}
i8272::i8272(Cycles clock_rate, int clock_rate_multiplier, int revolutions_per_minute) :
Storage::Disk::MFMController(clock_rate, clock_rate_multiplier, revolutions_per_minute) {
Storage::Disk::MFMController(clock_rate, clock_rate_multiplier, revolutions_per_minute),
status_(StatusRQM),
interesting_event_mask_((int)Event8272::CommandByte),
resume_point_(0),
delay_time_(0) {
posit_event((int)Event8272::CommandByte);
}
void i8272::run_for(Cycles cycles) {
Storage::Disk::MFMController::run_for(cycles);
if(delay_time_ > 0) {
if(cycles.as_int() >= delay_time_) {
delay_time_ = 0;
posit_event((int)Event8272::Timer);
} else {
delay_time_ -= cycles.as_int();
}
}
}
void i8272::set_register(int address, uint8_t value) {
// don't consider attempted sets to the status register
if(!address) return;
// TODO: if not accepting commands, return
// if not ready for commands, do nothing
if(!(status_ & StatusRQM)) return;
// accumulate latest byte in the command byte sequence
command_.push_back(value);
size_t necessary_length;
switch(command_[0] & 0x1f) {
case 0x06: // read data
necessary_length = 9;
break;
case 0x0b: // read deleted data
necessary_length = 9;
break;
case 0x05: // write data
necessary_length = 9;
break;
case 0x09: // write deleted data
necessary_length = 9;
break;
case 0x02: // read track
necessary_length = 9;
break;
case 0x0a: // read ID
necessary_length = 2;
break;
case 0x0d: // format track
necessary_length = 6;
break;
case 0x11: // scan low
necessary_length = 9;
break;
case 0x19: // scan low or equal
necessary_length = 9;
break;
case 0x1d: // scan high or equal
necessary_length = 9;
break;
case 0x07: // recalibrate
necessary_length = 2;
break;
case 0x08: // sense interrupt status
necessary_length = 1;
break;
case 0x03: // specify
necessary_length = 3;
break;
case 0x04: // sense drive status
necessary_length = 2;
break;
case 0x0f: // seek
necessary_length = 3;
break;
default: // invalid
necessary_length = 1;
break;
}
printf("8272 set register %d to %02x\n", address, value);
if(command_.size() == necessary_length) {
printf("8272 Perform!\n");
command_.clear();
}
posit_event((int)Event8272::CommandByte);
}
uint8_t i8272::get_register(int address) {
@ -92,9 +55,161 @@ uint8_t i8272::get_register(int address) {
return 0xff;
} else {
printf("8272 get status\n");
return 0x80;
return status_;
}
}
void i8272::posit_event(Event type) {
#define BEGIN_SECTION() switch(resume_point_) { default:
#define END_SECTION() }
#define WAIT_FOR_EVENT(mask) resume_point_ = __LINE__; interesting_event_mask_ = (int)mask; return; case __LINE__:
void i8272::posit_event(int type) {
if(!(interesting_event_mask_ & type)) return;
interesting_event_mask_ &= ~type;
BEGIN_SECTION();
wait_for_command:
set_data_mode(Storage::Disk::MFMController::DataMode::Scanning);
command_.clear();
wait_for_complete_command_sequence:
status_ |= StatusRQM;
WAIT_FOR_EVENT(Event8272::CommandByte)
status_ &= ~StatusRQM;
switch(command_[0] & 0x1f) {
case 0x06: // read data
if(command_.size() < 9) goto wait_for_complete_command_sequence;
goto read_data;
case 0x0b: // read deleted data
if(command_.size() < 9) goto wait_for_complete_command_sequence;
goto read_deleted_data;
case 0x05: // write data
if(command_.size() < 9) goto wait_for_complete_command_sequence;
goto write_data;
case 0x09: // write deleted data
if(command_.size() < 9) goto wait_for_complete_command_sequence;
goto write_deleted_data;
case 0x02: // read track
if(command_.size() < 9) goto wait_for_complete_command_sequence;
goto read_track;
case 0x0a: // read ID
if(command_.size() < 2) goto wait_for_complete_command_sequence;
goto read_id;
case 0x0d: // format track
if(command_.size() < 6) goto wait_for_complete_command_sequence;
goto format_track;
case 0x11: // scan low
if(command_.size() < 9) goto wait_for_complete_command_sequence;
goto scan_low;
case 0x19: // scan low or equal
if(command_.size() < 9) goto wait_for_complete_command_sequence;
goto scan_low_or_equal;
case 0x1d: // scan high or equal
if(command_.size() < 9) goto wait_for_complete_command_sequence;
goto scan_high_or_equal;
case 0x07: // recalibrate
if(command_.size() < 2) goto wait_for_complete_command_sequence;
goto recalibrate;
case 0x08: // sense interrupt status
goto sense_interrupt_status;
case 0x03: // specify
if(command_.size() < 3) goto wait_for_complete_command_sequence;
goto specify;
case 0x04: // sense drive status
if(command_.size() < 2) goto wait_for_complete_command_sequence;
goto sense_drive_status;
case 0x0f: // seek
if(command_.size() < 3) goto wait_for_complete_command_sequence;
goto seek;
default: // invalid
goto invalid;
}
read_data:
printf("Read data unimplemented!!");
goto wait_for_command;
read_deleted_data:
printf("Read deleted data unimplemented!!");
goto wait_for_command;
write_data:
printf("Write data unimplemented!!");
goto wait_for_command;
write_deleted_data:
printf("Write deleted data unimplemented!!");
goto wait_for_command;
read_track:
printf("Read track unimplemented!!");
goto wait_for_command;
read_id:
printf("Read ID unimplemented!!");
goto wait_for_command;
format_track:
printf("Fromat track unimplemented!!");
goto wait_for_command;
scan_low:
printf("Scan low unimplemented!!");
goto wait_for_command;
scan_low_or_equal:
printf("Scan low or equal unimplemented!!");
goto wait_for_command;
scan_high_or_equal:
printf("Scan high or equal unimplemented!!");
goto wait_for_command;
recalibrate:
printf("Recalibrate unimplemented!!");
goto wait_for_command;
sense_interrupt_status:
printf("Sense interrupt status unimplemented!!");
goto wait_for_command;
specify:
printf("Specify");
step_rate_time_ = command_[1] &0xf0; // i.e. 16 to 240m
head_unload_time_ = command_[1] & 0x0f; // i.e. 1 to 16ms
head_load_time_ = command_[2] & ~1; // i.e. 2 to 254 ms in increments of 2ms
dma_mode_ = !(command_[2] & 1);
goto wait_for_command;
sense_drive_status:
printf("Sense drive status unimplemented!!");
goto wait_for_command;
seek:
printf("Seek unimplemented!!");
goto wait_for_command;
invalid:
// A no-op, causing the FDC to go back into standby mode.
goto wait_for_command;
END_SECTION()
}

View File

@ -26,9 +26,24 @@ class i8272: public Storage::Disk::MFMController {
uint8_t get_register(int address);
private:
void posit_event(Event type);
void posit_event(int type);
uint8_t status_;
std::vector<uint8_t> command_;
enum class Event8272: int {
CommandByte = (1 << 3),
Timer = (1 << 4),
};
int interesting_event_mask_;
int resume_point_;
int delay_time_;
int step_rate_time_;
int head_unload_time_;
int head_load_time_;
bool dma_mode_;
};
}