aiie/teensy/teensy.ino

424 lines
11 KiB
C++

#include <Arduino.h>
#include <ff.h> // uSDFS
#include <SPI.h>
#include <EEPROM.h>
#include <TimeLib.h>
#include <TimerOne.h>
#include "bios.h"
#include "cpu.h"
#include "applevm.h"
#include "teensy-display.h"
#include "teensy-keyboard.h"
#include "teensy-speaker.h"
#include "teensy-paddles.h"
#include "teensy-filemanager.h"
#define RESETPIN 39
#define BATTERYPIN A19
#define SPEAKERPIN A21
#include "globals.h"
#include "teensy-crash.h"
volatile float nextInstructionMicros;
volatile float startMicros;
FATFS fatfs; /* File system object */
BIOS bios;
enum {
D_NONE = 0,
D_SHOWFPS = 1,
D_SHOWMEMFREE = 2,
D_SHOWPADDLES = 3,
D_SHOWPC = 4,
D_SHOWCYCLES = 5,
D_SHOWBATTERY = 6,
D_SHOWTIME = 7
};
uint8_t debugMode = D_NONE;
static time_t getTeensy3Time() { return Teensy3Clock.get(); }
#define ESP_TXD 51
#define ESP_CHPD 52
#define ESP_RST 53
#define ESP_RXD 40
#define ESP_GPIO0 41
#define ESP_GPIO2 42
void setup()
{
Serial.begin(230400);
/* while (!Serial) {
; // wait for serial port to connect. Needed for Leonardo only
}
Serial.println("hi");
*/
delay(100); // let the serial port connect if it's gonna
enableFaultHandler();
// set the Time library to use Teensy 3.0's RTC to keep time
setSyncProvider(getTeensy3Time);
delay(100); // don't know if we need this
if (timeStatus() == timeSet) {
Serial.println("RTC set from Teensy");
} else {
Serial.println("Error while setting RTC");
}
TCHAR *device = (TCHAR *)_T("0:/");
f_mount (&fatfs, device, 0); /* Mount/Unmount a logical drive */
pinMode(RESETPIN, INPUT);
digitalWrite(RESETPIN, HIGH);
analogReference(EXTERNAL); // 3.3v external, or 1.7v internal. We need 1.7 internal for the battery level, which means we're gonna have to do something about the paddles :/
analogReadRes(8); // We only need 8 bits of resolution (0-255) for battery & paddles
analogReadAveraging(4); // ?? dunno if we need this or not.
analogWriteResolution(12);
pinMode(SPEAKERPIN, OUTPUT); // analog speaker output, used as digital volume control
pinMode(BATTERYPIN, INPUT);
Serial.println("creating virtual hardware");
g_speaker = new TeensySpeaker(SPEAKERPIN);
Serial.println(" fm");
// First create the filemanager - the interface to the host file system.
g_filemanager = new TeensyFileManager();
// Construct the interface to the host display. This will need the
// VM's video buffer in order to draw the VM, but we don't have that
// yet.
Serial.println(" display");
g_display = new TeensyDisplay();
// Next create the virtual CPU. This needs the VM's MMU in order to
// run, but we don't have that yet.
Serial.println(" cpu");
g_cpu = new Cpu();
// Create the virtual machine. This may read from g_filemanager to
// get ROMs if necessary. (The actual Apple VM we've built has them
// compiled in, though.) It will create its virutal hardware (MMU,
// video driver, floppy, paddles, whatever).
Serial.println(" vm");
g_vm = new AppleVM();
// Now that the VM exists and it has created an MMU, we tell the CPU
// how to access memory through the MMU.
Serial.println(" [setMMU]");
g_cpu->SetMMU(g_vm->getMMU());
// And the physical keyboard needs hooks in to the virtual keyboard...
Serial.println(" keyboard");
g_keyboard = new TeensyKeyboard(g_vm->getKeyboard());
Serial.println(" paddles");
g_paddles = new TeensyPaddles(A23, A24, 1, 1);
// Now that all the virtual hardware is glued together, reset the VM
Serial.println("Resetting VM");
g_vm->Reset();
g_display->redraw();
// g_display->blit();
Serial.println("Reading prefs");
readPrefs(); // read from eeprom and set anything we need setting
Serial.println("free-running");
startMicros = 0;
nextInstructionMicros = micros();
// Debugging: insert a disk on startup...
// ((AppleVM *)g_vm)->insertDisk(0, "/A2DISKS/UTIL/mock2dem.dsk", false);
// ((AppleVM *)g_vm)->insertDisk(0, "/A2DISKS/JORJ/disk_s6d1.dsk", false);
// ((AppleVM *)g_vm)->insertDisk(0, "/A2DISKS/GAMES/ALIBABA.DSK", false);
pinMode(56, OUTPUT);
pinMode(57, OUTPUT);
Timer1.initialize(3);
Timer1.attachInterrupt(runCPU);
Timer1.start();
}
// FIXME: move these memory-related functions elsewhere...
// This only gives you an estimated free mem size. It's not perfect.
uint32_t FreeRamEstimate()
{
uint32_t stackTop;
uint32_t heapTop;
// current position of the stack.
stackTop = (uint32_t) &stackTop;
// current position of heap.
void* hTop = malloc(1);
heapTop = (uint32_t) hTop;
free(hTop);
// The difference is the free, available ram.
return stackTop - heapTop;
}
#include "malloc.h"
int heapSize(){
return mallinfo().uordblks;
}
void biosInterrupt()
{
Timer1.stop();
// wait for the interrupt button to be released
while (digitalRead(RESETPIN) == LOW)
;
// invoke the BIOS
if (bios.runUntilDone()) {
// if it returned true, we have something to store persistently in EEPROM.
writePrefs();
}
// if we turned off debugMode, make sure to clear the debugMsg
if (debugMode == D_NONE) {
g_display->debugMsg("");
}
// clear the CPU next-step counters
g_cpu->cycles = 0;
nextInstructionMicros = micros();
startMicros = micros();
// Drain the speaker queue (FIXME: a little hacky)
g_speaker->maintainSpeaker(-1);
// Force the display to redraw
((AppleDisplay*)(g_vm->vmdisplay))->modeChange();
// Poll the keyboard before we start, so we can do selftest on startup
g_keyboard->maintainKeyboard();
Timer1.start();
}
//bool debugState = false;
//bool debugLCDState = false;
void runCPU()
{
if (micros() >= nextInstructionMicros) {
// Debugging: to watch when the CPU is triggered...
//debugState = !debugState;
// digitalWrite(56, debugState);
uint8_t executed = g_cpu->Run(24);
// The CPU of the Apple //e ran at 1.023 MHz. Adjust when we think
// the next instruction should run based on how long the execution
// was ((1000/1023) * numberOfCycles) - which is about 97.8%.
nextInstructionMicros = startMicros + (float)g_cpu->cycles * 0.978;
// Timing-critical paddle and keyboard handling
((AppleVM *)g_vm)->cpuMaintenance(g_cpu->cycles);
}
// Timing-crtical audio handling
g_speaker->beginMixing();
// estimate of current cpu cycle counter, delayed a bit
float speakerTick = ((float)micros() - 100.0 - (float)startMicros) / 0.978;
g_speaker->maintainSpeaker(speakerTick);
}
void loop()
{
if (digitalRead(RESETPIN) == LOW) {
// This is the BIOS interrupt. We immediately act on it.
biosInterrupt();
}
((AppleVM*)g_vm)->disk6->fillDiskBuffer();
g_keyboard->maintainKeyboard();
//debugLCDState = !debugLCDState;
//digitalWrite(57, debugLCDState);
doDebugging();
// Only redraw if the CPU is caught up; and then we'll suspend the
// CPU to draw a full frame.
// Note that this breaks audio, b/c it's real-time and requires the
// CPU running to change the audio line's value. So we need to EITHER
//
// - delay the audio line by at least the time it takes for one
// display update, OR
// - lock display updates so the CPU can update the memory, but we
// keep drawing what was going to be displayed
//
// The Timer1.stop()/start() is bad. Using it, the display doesn't
// tear; but the audio is also broken. Taking it out, audio is good
// but the display tears.
Timer1.stop();
g_vm->vmdisplay->lockDisplay();
if (g_vm->vmdisplay->needsRedraw()) {
AiieRect what = g_vm->vmdisplay->getDirtyRect();
g_vm->vmdisplay->didRedraw();
g_display->blit(what);
}
g_vm->vmdisplay->unlockDisplay();
Timer1.start();
static unsigned long nextBattCheck = 0;
static int batteryLevel = 0; // static for debugging code! When done
// debugging, this can become a local
// in the appropriate block below
if (millis() >= nextBattCheck) {
// FIXME: what about rollover?
nextBattCheck = millis() + 3 * 1000; // check every 30 seconds
// This is a bit disruptive - but the external 3.3v will drop along with the battery level, so we should use the more stable (I hope) internal 1.7v.
// The alternative is to build a more stable buck/boost regulator for reference...
analogReference(INTERNAL);
batteryLevel = analogRead(BATTERYPIN);
analogReference(EXTERNAL);
/* LiIon charge to a max of 4.2v; and we should not let them discharge below about 3.5v.
* With a resistor voltage divider of Z1=39k, Z2=10k we're looking at roughly 20.4% of
* those values: (10/49) * 4.2 = 0.857v, and (10/49) * 3.5 = 0.714v. Since the external
* voltage reference flags as the battery drops, we can't use that as an absolute
* reference. So using the INTERNAL 1.1v reference, that should give us a reasonable
* range, in theory; the math shows the internal reference to be about 1.27v (assuming
* the resistors are indeed 39k and 10k, which is almost certainly also wrong). But
* then the high end would be 172, and the low end is about 142, which matches my
* actual readings here very well.
*
* Actual measurements:
* 3.46v = 144 - 146
* 4.21v = 172
*/
#if 1
Serial.print("battery: ");
Serial.println(batteryLevel);
#endif
if (batteryLevel < 146)
batteryLevel = 146;
if (batteryLevel > 168)
batteryLevel = 168;
batteryLevel = map(batteryLevel, 146, 168, 0, 100);
g_display->drawBatteryStatus(batteryLevel);
}
}
void doDebugging()
{
char buf[25];
switch (debugMode) {
case D_SHOWFPS:
// display some FPS data
static uint32_t startAt = millis();
static uint32_t loopCount = 0;
loopCount++;
time_t lenSecs;
lenSecs = (millis() - startAt) / 1000;
if (lenSecs >= 5) {
sprintf(buf, "%lu FPS", loopCount / lenSecs);
g_display->debugMsg(buf);
startAt = millis();
loopCount = 0;
}
break;
case D_SHOWMEMFREE:
sprintf(buf, "%lu %u", FreeRamEstimate(), heapSize());
g_display->debugMsg(buf);
break;
case D_SHOWPADDLES:
sprintf(buf, "%u %u", g_paddles->paddle0(), g_paddles->paddle1());
g_display->debugMsg(buf);
break;
case D_SHOWPC:
sprintf(buf, "%X", g_cpu->pc);
g_display->debugMsg(buf);
break;
case D_SHOWCYCLES:
sprintf(buf, "%lX", g_cpu->cycles);
g_display->debugMsg(buf);
break;
case D_SHOWBATTERY:
sprintf(buf, "BAT %d", analogRead(BATTERYPIN));
g_display->debugMsg(buf);
break;
case D_SHOWTIME:
sprintf(buf, "%.2d:%.2d:%.2d", hour(), minute(), second());
g_display->debugMsg(buf);
break;
}
}
typedef struct _prefs {
uint32_t magic;
int16_t volume;
} prefs;
// Fun trivia: the Apple //e was in production from January 1983 to
// November 1993. And the 65C02 in them supported weird BCD math modes.
#define MAGIC 0x01831093
void readPrefs()
{
prefs p;
uint8_t *pp = (uint8_t *)&p;
Serial.println("reading prefs");
for (uint8_t i=0; i<sizeof(prefs); i++) {
*pp++ = EEPROM.read(i);
}
if (p.magic == MAGIC) {
// looks valid! Use it.
Serial.println("prefs valid! Restoring volume");
if (p.volume > 15) {
p.volume = 15;
}
if (p.volume < 0) {
p.volume = 0;
}
g_volume = p.volume;
return;
}
// use defaults
g_volume = 0;
}
void writePrefs()
{
Serial.println("writing prefs");
Timer1.stop();
prefs p;
uint8_t *pp = (uint8_t *)&p;
p.magic = MAGIC;
p.volume = g_volume;
for (uint8_t i=0; i<sizeof(prefs); i++) {
EEPROM.write(i, *pp++);
}
Timer1.start();
}