implement drive motor-off one-second delay

src/Makefile.am

@@ -12,7 +12,7 @@ epple2_CPPFLAGS = $(AM_CPPFLAGS) -DETCDIR=\"$(sysconfdir)\"
 
 epple2_SOURCES = a2colorsobserved.cpp addressbus.cpp analogtv.cpp apple2.cpp \
 applentsc.cpp card.cpp cassette.cpp clipboardhandler.cpp clockcard.cpp \
-configep2.cpp cpu.cpp diskbytes.cpp diskcontroller.cpp drive.cpp \
+configep2.cpp cpu.cpp diskbytes.cpp diskcontroller.cpp drive.cpp drivemotor.cpp \
 emptyslot.cpp emulator.cpp firmwarecard.cpp gui.cpp hypermode.cpp \
 keyboard.cpp keyboardbuffermode.cpp languagecard.cpp lowpass_1_5_mhz.cpp \
 lowpass_3_58_mhz.cpp lss.cpp main.cpp memory.cpp paddlebuttonstates.cpp \
@@ -26,7 +26,7 @@ StateCalculator.cpp  Trace.cpp  TransCache.cpp  TransNetwork.cpp
 
 noinst_HEADERS = a2colorsobserved.h addressbus.h analogtv.h apple2.h applentsc.h \
 card.h cassette.h clipboardhandler.h clockcard.h configep2.h cpu.h diskbytes.h \
-diskcontroller.h drive.h e2const.h emptyslot.h emulator.h firmwarecard.h font3x5.h gui.h \
+diskcontroller.h drive.h drivemotor.h e2const.h emptyslot.h emulator.h firmwarecard.h font3x5.h gui.h \
 hypermode.h keyboardbuffermode.h keyboard.h languagecard.h lowpass_1_5_mhz.h \
 lowpass_3_58_mhz.h lss.h memory.h paddlebuttonstates.h paddles.h picturegenerator.h \
 powerupreset.h raminitializer.h screenimage.h slots.h speakerclicker.h \

src/diskcontroller.cpp

@@ -45,21 +45,19 @@ unsigned char DiskController::io(const unsigned short addr, const unsigned char
     case 2:
     case 3:
         this->currentDrive->setMagnet(q,on);
-        this->gui.setTrack(this->slot,getCurrentDriveNumber(),getTrack());
+        this->gui.setTrack(this->slot, getCurrentDriveNumber(), getTrack());
         break;
     case 4:
-        this->motorOn = on;
-        this->gui.setIO(this->slot,getCurrentDriveNumber(),on);
+        this->motor.power(on);
         break;
     case 5:
-        this->gui.clearCurrentDrive(this->slot,getCurrentDriveNumber());
+        this->gui.clearCurrentDrive(this->slot, getCurrentDriveNumber());
         this->currentDrive = (on ? &this->drive2 : &this->drive1);
-        this->gui.setCurrentDrive(this->slot,getCurrentDriveNumber(),getTrack(),this->motorOn);
+        this->gui.setCurrentDrive(this->slot, getCurrentDriveNumber(),getTrack(), this->motor.isOn());
         break;
     case 6:
         this->load = on;
         // TODO when to do these GUI updates?
-//        this->gui.setIO(this->slot,getCurrentDriveNumber(),this->motorOn);
 //        this->gui.setDirty(this->slot,getCurrentDriveNumber(),true);
         break;
     case 7:
@@ -83,9 +81,11 @@ unsigned char DiskController::io(const unsigned short addr, const unsigned char
  * (When the motor is on, that is.)
  */
 void DiskController::tick() {
-    if (!this->motorOn) {
+    this->gui.setIO(this->slot, getCurrentDriveNumber(), this->motor.isOn());
+    if (!this->motor.isOn()) {
         return;
     }
+    this->motor.tick(); // only need to send tick when motor is powered on
 
     rotateCurrentDisk();
 

src/diskcontroller.h

@@ -17,6 +17,7 @@
 */
 #include "card.h"
 #include "drive.h"
+#include "drivemotor.h"
 #include "wozfile.h"
 #include "lss.h"
 #include "screenimage.h"
@@ -41,7 +42,12 @@ private:
 
         bool load; // Q6
         bool write; // Q7
-        bool motorOn; // TODO WOZ make it delay power-off by about 1 second.
+
+        /*
+         * Only one drive's motor can be on at a time,
+         * so we only need one instance.
+         */
+        DriveMotor motor;
 
         // Maintain a copy of the last thing on the data bus, so it can
         // be read by the LSS algorithm when needed.
@@ -57,7 +63,7 @@ private:
         // TODO for a rev. 0 motherboard, the disk controller will auto reset the CPU (see UA2, 9-13)
 
         void writeBit(bool on) {
-                if (!this->motorOn) {
+                if (!this->motor.isOn()) {
                         return;
                 }
                 this->currentDrive->writeBit(on);
@@ -89,7 +95,7 @@ public:
 		this->gui.clearCurrentDrive(this->slot,getCurrentDriveNumber());
 
 		this->currentDrive = &this->drive1;
-		this->motorOn = false;
+                this->motor.reset();
 
 		this->gui.setCurrentDrive(this->slot,getCurrentDriveNumber(),getTrack(),false);
 	}
@@ -119,7 +125,7 @@ public:
 
 	bool isMotorOn()
 	{
-		return this->motorOn;
+                return this->motor.isOn();
 	}
 
 //        const WozFile& getDiskBytes(unsigned char disk)

src/drivemotor.cpp

@@ -0,0 +1,62 @@
+/*
+    epple2
+    Copyright (C) 2018 by Christopher A. Mosher <cmosher01@gmail.com>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY, without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "drivemotor.h"
+#include "e2const.h"
+//#include <cstdio>
+
+DriveMotor::DriveMotor():
+    on(false),
+    pendingTicks(0) {
+}
+
+DriveMotor::~DriveMotor() {
+}
+
+bool DriveMotor::isOn() const {
+    return this->on;
+}
+
+void DriveMotor::power(bool on) {
+    if (on) {
+        this->on = true;
+//        printf("MOTOR: power on\n");
+    } else {
+        // delay power-off by about one second (a little longer, for momentum)
+        // U.A.II, p. 9-13 (NE556 timer)
+        this->pendingTicks = (int)(E2Const::AVG_CPU_HZ*1.2);
+//        printf("MOTOR: power off pending...\n");
+    }
+}
+
+void DriveMotor::reset() {
+    // immediate power off
+    // U.A.II, p. 9-13
+    this->on = false;
+//    printf("MOTOR: power off (immediate)\n");
+}
+
+void DriveMotor::tick() {
+    if (this->pendingTicks > 0) {
+        --this->pendingTicks;
+        if (this->pendingTicks == 0){
+            this->on = false;
+//            printf("MOTOR: power off\n");
+        }
+    }
+}

src/drivemotor.h

@@ -0,0 +1,39 @@
+/*
+    epple2
+    Copyright (C) 2018 by Christopher A. Mosher <cmosher01@gmail.com>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY, without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef DRIVEMOTOR_H
+#define DRIVEMOTOR_H
+
+#include <cstdint>
+
+class DriveMotor {
+private:
+    bool on;
+    std::uint32_t pendingTicks;
+
+public:
+    DriveMotor();
+    ~DriveMotor();
+
+    bool isOn() const;
+    void power(bool on);
+    void reset();
+    void tick();
+};
+
+#endif // DRIVEMOTOR_H

src/wozfile.cpp

@@ -312,7 +312,7 @@ void WozFile::rotateOneBit(std::uint8_t currentQuarterTrack) {
 
 bool WozFile::getBit(std::uint8_t currentQuarterTrack) {
     if (!isLoaded()) {
-        printf("No disk to read from; will generate random data.\n");
+//        printf("No disk to read from; will generate random data.\n");
         return false; // there's no disk, so no pulse
     }