6502/CLK
1
0
Fork 0
mirror of https://github.com/TomHarte/CLK.git synced 2024-09-27 18:55:48 +00:00
Code Issues Projects Releases Wiki Activity

Sought to introduce head loading and unloading delays.

Browse Source
This commit is contained in:
Thomas Harte 2017-08-12 09:36:21 -04:00
parent 8c33ac71ee
commit e7db2a2f6d
2 changed files with 74 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

70
Components/8272/i8272.cpp
View File

@ -29,7 +29,7 @@ i8272::i8272(Cycles clock_rate, int clock_rate_multiplier, int revolutions_per_m
interesting_event_mask_((int)Event8272::CommandByte),
resume_point_(0),
delay_time_(0),
status_{0, 0, 0} {
head_timers_running_(0) {
posit_event((int)Event8272::CommandByte);
}
@ -69,6 +69,23 @@ void i8272::run_for(Cycles cycles) {
}
}
}
// check for any head unloads
if(head_timers_running_) {
for(int c = 0; c < 4; c++) {
for(int h = 0; h < 2; h++) {
if(drives_[c].head_unload_delay[c] > 0) {
if(cycles.as_int() >= drives_[c].head_unload_delay[c]) {
drives_[c].head_unload_delay[c] = 0;
drives_[c].head_is_loaded[c] = false;
head_timers_running_--;
} else {
drives_[c].head_unload_delay[c] -= cycles.as_int();
}
}
}
}
}
}
void i8272::set_register(int address, uint8_t value) {
@ -109,6 +126,7 @@ void i8272::set_disk(std::shared_ptr<Storage::Disk::Disk> disk, int drive) {
#define END_SECTION() }
#define WAIT_FOR_EVENT(mask) resume_point_ = __LINE__; interesting_event_mask_ = (int)mask; return; case __LINE__:
#define WAIT_FOR_TIME(ms) resume_point_ = __LINE__; interesting_event_mask_ = (int)Event8272::Timer; delay_time_ = ms * 8000; case __LINE__: if(delay_time_) return;
#define PASTE(x, y) x##y
#define CONCAT(x, y) PASTE(x, y)
@ -136,10 +154,31 @@ void i8272::set_disk(std::shared_ptr<Storage::Disk::Disk> disk, int drive) {
#define SET_DRIVE_HEAD_MFM() \
if(!dma_mode_) main_status_ |= StatusNonDMAExecuting; \
set_drive(drives_[command_[1]&3].drive); \
active_drive_ = command_[1]&3; \
active_head_ = (command_[1] >> 2)&1; \
set_drive(drives_[active_drive_].drive); \
drives_[active_drive_].clear_status(); \
drives_[active_drive_].drive->set_head((unsigned int)active_head_); \
set_is_double_density(command_[0] & 0x40); \
invalidate_track();
#define LOAD_HEAD() \
if(!drives_[active_drive_].head_is_loaded[active_head_]) { \
drives_[active_drive_].head_is_loaded[active_head_] = true; \
WAIT_FOR_TIME(head_load_time_); \
} else { \
if(drives_[active_drive_].head_unload_delay[active_head_] > 0) { \
drives_[active_drive_].head_unload_delay[active_head_] = 0; \
head_timers_running_--; \
} \
}
#define SCHEDULE_HEAD_UNLOAD() \
if(drives_[active_drive_].head_unload_delay[active_head_] == 0) { \
head_timers_running_++; \
} \
drives_[active_drive_].head_unload_delay[active_head_] = head_unload_time_;
void i8272::posit_event(int event_type) {
if(!(interesting_event_mask_ & event_type)) return;
interesting_event_mask_ &= ~event_type;
@ -247,13 +286,15 @@ void i8272::posit_event(int event_type) {
// Establishes the drive and head being addressed, and whether in double density mode; populates the internal
// cylinder, head, sector and size registers from the command stream.
status_[0] = status_[1] = status_[2] = 0;
SET_DRIVE_HEAD_MFM();
cylinder_ = command_[2];
head_ = command_[3];
sector_ = command_[4];
size_ = command_[5];
// TODO: is the head loaded?
LOAD_HEAD();
read_next_data:
// Sets a maximum index hole limit of 2 then performs a find header/read header loop, continuing either until
@ -303,8 +344,8 @@ void i8272::posit_event(int event_type) {
read_data_not_found:
printf("Not found\n");
status_[1] |= 0x4;
status_[0] = 0x40; // (status_[0] & ~0xc0) |
drives_[active_drive_].status[1] |= 0x4;
drives_[active_drive_].status[0] = 0x40; // (status_[0] & ~0xc0) |
goto post_st012chrn;
read_deleted_data:
@ -328,6 +369,7 @@ void i8272::posit_event(int event_type) {
// Establishes the drive and head being addressed, and whether in double density mode.
printf("Read ID\n");
SET_DRIVE_HEAD_MFM();
LOAD_HEAD();
// Sets a maximum index hole limit of 2 then waits either until it finds a header mark or sees too many index holes.
// If a header mark is found, reads in the following bytes that produce a header. Otherwise branches to data not found.
@ -372,7 +414,7 @@ void i8272::posit_event(int event_type) {
// a recalibrate the target is -1 and ::run_for knows that -1 means the terminal condition is the drive
// returning that its at track zero, and that it should reset the drive's current position once reached.
if(drives_[command_[1]&3].phase != Drive::Seeking) {
status_[0] = status_[1] = status_[2] = 0;
drives_[command_[1]&3].clear_status();
int drive = command_[1]&3;
drives_[drive].phase = Drive::Seeking;
drives_[drive].steps_taken = 0;
@ -404,11 +446,11 @@ void i8272::posit_event(int event_type) {
// If a drive was found, return its results. Otherwise return a single 0x80.
if(found_drive != -1) {
drives_[found_drive].phase = Drive::NotSeeking;
status_[0] = (uint8_t)found_drive | 0x20;
drives_[found_drive].status[0] = (uint8_t)found_drive | 0x20;
main_status_ &= ~(1 << found_drive);
result_stack_.push_back(drives_[found_drive].head_position);
result_stack_.push_back(status_[0]);
result_stack_.push_back(drives_[found_drive].status[0]);
} else {
result_stack_.push_back(0x80);
}
@ -439,20 +481,22 @@ void i8272::posit_event(int event_type) {
// Performs any invalid command.
invalid:
// A no-op, but posts ST0.
result_stack_.push_back(status_[0]);
// A no-op, but posts ST0 (but which ST0?)
result_stack_.push_back(0x80);
goto post_result;
// Posts ST0, ST1, ST2, C, H, R and N as a result phase.
post_st012chrn:
SCHEDULE_HEAD_UNLOAD();
result_stack_.push_back(size_);
result_stack_.push_back(sector_);
result_stack_.push_back(head_);
result_stack_.push_back(cylinder_);
result_stack_.push_back(status_[2]);
result_stack_.push_back(status_[1]);
result_stack_.push_back(status_[0]);
result_stack_.push_back(drives_[active_drive_].status[2]);
result_stack_.push_back(drives_[active_drive_].status[1]);
result_stack_.push_back(drives_[active_drive_].status[0]);
goto post_result;

19
Components/8272/i8272.hpp
View File

@ -31,7 +31,6 @@ class i8272: public Storage::Disk::MFMController {
private:
void posit_event(int type);
uint8_t main_status_;
uint8_t status_[3];
std::vector<uint8_t> command_;
std::vector<uint8_t> result_stack_;
@ -53,7 +52,9 @@ class i8272: public Storage::Disk::MFMController {
struct Drive {
uint8_t head_position;
uint8_t status[3];
// Seeking state.
enum Phase {
NotSeeking,
Seeking,
@ -63,15 +64,29 @@ class i8272: public Storage::Disk::MFMController {
int steps_taken;
int target_head_position; // either an actual number, or -1 to indicate to step until track zero
// Head state.
int head_unload_delay[2];
bool head_is_loaded[2];
std::shared_ptr<Storage::Disk::Drive> drive;
Drive() : head_position(0), phase(NotSeeking), drive(new Storage::Disk::Drive) {};
Drive() :
head_position(0), phase(NotSeeking),
drive(new Storage::Disk::Drive),
status{0, 0, 0}, head_is_loaded{false, false} {};
void clear_status() {
status[0] = status[1] = status[2] = 0;
}
} drives_[4];
int head_timers_running_;
uint8_t header_[6];
int distance_into_section_;
int index_hole_limit_;
int active_drive_;
int active_head_;
uint8_t cylinder_, head_, sector_, size_;
bool seek_is_satisfied(int drive);