diff --git a/devices/floppy/superdrive.cpp b/devices/floppy/superdrive.cpp
index 8cb6f9e..1416ad8 100644
--- a/devices/floppy/superdrive.cpp
+++ b/devices/floppy/superdrive.cpp
@@ -40,6 +40,7 @@ MacSuperDrive::MacSuperDrive()
this->eject_latch = 0; // eject latch is off
this->drive_mode = RecMethod::MFM; // assume MFM mode by default
this->motor_stat = 0; // spindle motor is off
+ this->head_pos = 0; // current head position
this->is_ready = 0; // drive not ready
}
@@ -53,6 +54,14 @@ void MacSuperDrive::command(uint8_t addr, uint8_t value)
case CommandAddr::Step_Direction:
this->step_dir = value ? -1 : 1;
break;
+ case CommandAddr::Do_Step:
+ if (!value) {
+ this->head_pos += this->step_dir;
+ if (this->head_pos < 0)
+ this->head_pos = 0;
+ this->track_zero = this->head_pos == 0;
+ }
+ break;
case CommandAddr::Motor_On_Off:
new_motor_stat = value ^ 1;
if (this->motor_stat != new_motor_stat) {
diff --git a/devices/floppy/superdrive.h b/devices/floppy/superdrive.h
index 55b5442..f74ced8 100644
--- a/devices/floppy/superdrive.h
+++ b/devices/floppy/superdrive.h
@@ -51,6 +51,7 @@ enum StatusAddr : uint8_t {
/** Apple Drive command addresses. */
enum CommandAddr : uint8_t {
Step_Direction = 0,
+ Do_Step = 1,
Motor_On_Off = 2,
Reset_Eject_Latch = 4,
Switch_Drive_Mode = 5,
@@ -87,7 +88,9 @@ private:
uint8_t motor_stat; // spindle motor status: 1 - on, 0 - off
uint8_t drive_mode; // drive mode: 0 - GCR, 1 - MFM
uint8_t is_ready;
+ uint8_t track_zero; // 1 - if head is at track zero
int step_dir; // step direction -1/+1
+ int head_pos; // track number the head is currently at
// physical parameters of the currently inserted disk
uint8_t media_kind;
diff --git a/devices/floppy/swim3.cpp b/devices/floppy/swim3.cpp
index ec68781..dd045c8 100644
--- a/devices/floppy/swim3.cpp
+++ b/devices/floppy/swim3.cpp
@@ -21,6 +21,7 @@ along with this program. If not, see .
/** @file Sander-Wozniak Machine 3 (SWIM3) emulation. */
+#include
#include
#include
#include
@@ -36,6 +37,7 @@ Swim3Ctrl::Swim3Ctrl()
this->setup_reg = 0;
this->mode_reg = 0;
this->int_reg = 0;
+ this->int_flags = 0;
this->int_mask = 0;
this->xfer_cnt = 0;
this->first_sec = 0xFF;
@@ -49,7 +51,7 @@ Swim3Ctrl::Swim3Ctrl()
uint8_t Swim3Ctrl::read(uint8_t reg_offset)
{
- uint8_t status_addr;
+ uint8_t status_addr, old_int_flags;
switch(reg_offset) {
case Swim3Reg::Phase:
@@ -60,9 +62,15 @@ uint8_t Swim3Ctrl::read(uint8_t reg_offset)
if (this->mode_reg & 2) { // internal drive?
status_addr = ((this->mode_reg & 0x20) >> 2) | (this->phase_lines & 7);
return ((this->int_drive->status(status_addr) & 1) << 2);
- } else {
- return 4;
}
+ return 4;
+ case Swim3Reg::Interrupt_Flags:
+ old_int_flags = this->int_flags;
+ this->int_flags = 0; // read from this register clears all flags
+ update_irq();
+ return old_int_flags;
+ case Swim3Reg::Interrupt_Mask:
+ return this->int_mask;
default:
LOG_F(INFO, "SWIM3: reading from 0x%X register", reg_offset);
}
@@ -71,6 +79,8 @@ uint8_t Swim3Ctrl::read(uint8_t reg_offset)
void Swim3Ctrl::write(uint8_t reg_offset, uint8_t value)
{
+ uint8_t old_mode_reg;
+
switch(reg_offset) {
case Swim3Reg::Param_Data:
this->pram = value;
@@ -91,12 +101,29 @@ void Swim3Ctrl::write(uint8_t reg_offset, uint8_t value)
break;
case Swim3Reg::Status_Mode0:
// ones in value clear the corresponding bits in the mode register
+ if ((this->mode_reg & value) & (SWIM3_GO | SWIM3_GO_STEP)) {
+ if (value & SWIM3_GO_STEP) {
+ stop_stepping();
+ } else {
+ stop_action();
+ }
+ }
this->mode_reg &= ~value;
break;
case Swim3Reg::Handshake_Mode1:
// ones in value set the corresponding bits in the mode register
+ if ((this->mode_reg ^ value) & (SWIM3_GO | SWIM3_GO_STEP)) {
+ if (value & SWIM3_GO_STEP) {
+ start_stepping();
+ } else {
+ start_action();
+ }
+ }
this->mode_reg |= value;
break;
+ case Swim3Reg::Step:
+ this->step_count = value;
+ break;
case Swim3Reg::Interrupt_Mask:
this->int_mask = value;
break;
@@ -104,3 +131,70 @@ void Swim3Ctrl::write(uint8_t reg_offset, uint8_t value)
LOG_F(INFO, "SWIM3: writing 0x%X to register 0x%X", value, reg_offset);
}
}
+
+void Swim3Ctrl::update_irq()
+{
+}
+
+void Swim3Ctrl::do_step()
+{
+ if (this->mode_reg & SWIM3_GO_STEP && this->step_count) { // are we still stepping?
+ // instruct the drive to perform single step in current direction
+ this->int_drive->command(MacSuperdrive::CommandAddr::Do_Step, 0);
+ if (--this->step_count == 0) {
+ if (this->step_timer_id) {
+ this->stop_stepping();
+ }
+ this->int_flags |= INT_STEP_DONE;
+ update_irq();
+ }
+ }
+}
+
+void Swim3Ctrl::start_stepping()
+{
+ if (!this->step_count) {
+ LOG_F(WARNING, "SWIM3: step_count is zero while go_step is active!");
+ return;
+ }
+
+ if ((((this->mode_reg & 0x20) >> 3) | (this->phase_lines & 3))
+ != MacSuperdrive::CommandAddr::Do_Step) {
+ LOG_F(WARNING, "SWIM3: invalid command address on the phase lines!");
+ return;
+ }
+
+ this->mode_reg |= SWIM3_GO_STEP;
+
+ // step count > 1 requires periodic task
+ if (this->step_count > 1) {
+ this->step_timer_id = TimerManager::get_instance()->add_cyclic_timer(
+ USECS_TO_NSECS(80),
+ [this]() {
+ this->do_step();
+ }
+ );
+ }
+
+ // perform the first step immediately
+ do_step();
+}
+
+void Swim3Ctrl::stop_stepping()
+{
+ // cancel stepping task
+ if (this->step_timer_id) {
+ TimerManager::get_instance()->cancel_timer(this->step_timer_id);
+ }
+ this->step_timer_id = 0;
+ this->step_count = 0; // not sure this one is required
+}
+
+void Swim3Ctrl::start_action()
+{
+ LOG_F(INFO, "SWIM3: action started!");
+}
+
+void Swim3Ctrl::stop_action()
+{
+}
diff --git a/devices/floppy/swim3.h b/devices/floppy/swim3.h
index 1a4d54c..c0bbebb 100644
--- a/devices/floppy/swim3.h
+++ b/devices/floppy/swim3.h
@@ -41,7 +41,7 @@ enum Swim3Reg : uint8_t {
Setup = 5,
Status_Mode0 = 6, // read: Status, write: zeroes to the mode register
Handshake_Mode1 = 7, // read: Handshake, write: ones to the mode register
- Interrupt = 8,
+ Interrupt_Flags = 8,
Step = 9,
Current_Track = 10,
Current_Sector = 11,
@@ -51,6 +51,17 @@ enum Swim3Reg : uint8_t {
Interrupt_Mask = 15
};
+/** Mode register bits. */
+enum {
+ SWIM3_GO = 0x08,
+ SWIM3_GO_STEP = 0x80,
+};
+
+/** Interrupt flags. */
+enum {
+ INT_STEP_DONE = 0x02,
+};
+
class Swim3Ctrl {
public:
Swim3Ctrl();
@@ -60,6 +71,14 @@ public:
uint8_t read(uint8_t reg_offset);
void write(uint8_t reg_offset, uint8_t value);
+protected:
+ void update_irq();
+ void start_stepping();
+ void do_step();
+ void stop_stepping();
+ void start_action();
+ void stop_action();
+
private:
std::unique_ptr int_drive;
@@ -67,10 +86,14 @@ private:
uint8_t mode_reg;
uint8_t phase_lines;
uint8_t int_reg;
+ uint8_t int_flags; // interrupt flags
uint8_t int_mask;
uint8_t pram; // parameter RAM: two nibbles = {late_time, early_time}
+ uint8_t step_count;
uint8_t first_sec;
uint8_t xfer_cnt;
+
+ int step_timer_id = 0;
};
}; // namespace Swim3