org.razvan.jzx
Class BaseSpectrum

java.lang.Object
  org.razvan.jzx.BaseComponent
      org.razvan.jzx.BaseSpectrum

Direct Known Subclasses:

Spectrum, Spectrum

public abstract class BaseSpectrum
extends BaseComponent

Base class extended by all Spectrum models (48k, 128k).

This class provides basic, common spectrum functionality for the various spectrum models.

Author:

Razvan Surdulescu (c) 2001 - 2006, Erik Kunze (c) 1995, 1996, 1997, Des Herriott (c) 1993, 1994
You may use and distribute this software for free provided you include this copyright notice. You may not sell this software, use my name for publicity reasons or modify the code without permission from me.

Field Summary

static long	FREQUENCY_MS The 20ms frequency of the interrupt clock.
static int	ISSUE_2 48k Spectrum model 2 (issue 2)
static int	ISSUE_3 48k Spectrum model 3 (issue 3)
protected Clock	m_clock The interrupt clock.
protected java.awt.Container	m_container Component that decorates the screen object for display in a Frame, Applet, etc.
protected Z80	m_cpu Contained reference to the Z80 CPU.
protected int	m_cyclesLine The number of CPU T-States per TV line.
protected long	m_frequency
protected BaseIO	m_io Contained reference to the I/O object.
protected int	m_issue The model (issue) of this Spectrum.
protected BaseKeyboard	m_keyboard Contained reference to the keyboard object.
protected BaseMemory	m_memory Contained reference to the memory object.
protected int	m_scale The current scale value for this Spectrum.
protected BaseScreen	m_screen Contained reference to the screen object.
protected java.awt.Label	m_status Label used to display various status messages.
protected int	m_tvLines The number of lines per TV frame.
protected int	m_vline The current vertical line being drawn.

Fields inherited from class org.razvan.jzx.BaseComponent

m_logger, m_spectrum

Constructor Summary

BaseSpectrum()

Method Summary

void	emulate() The main emulator loop.
java.awt.Component	getContainer() Return a Container that decorates the Spectrum screen and adds other UI elements such as a status bar.
Z80	getCPU() Trivial accessor for this Spectrum's CPU.
long	getFrequency() Get the frequency used by the m_clock.
BaseIO	getIO() Trivial accessor for this Spectrum's I/O.
int	getIssue() Trivial accessor for the issue (model) of this Spectrum.
BaseKeyboard	getKeyboard() Trivial accessor for this Spectrum's keyboard.
BaseMemory	getMemory() Trivial accessor for this Spectrum's memory.
abstract java.lang.String	getMode() String that describes the type of Spectrum ("48", "128").
int	getScale() Trivial accessor for the scale parameter of this Spectrum.
BaseScreen	getScreen() Trivial accessor for this Spectrum's screen.
int	getVline() Trivial accessor for the current TV line being drawn.
void	init(BaseSpectrum spectrum, ILogger logger) Allocate the clock object, and initialize all contained references (CPU, memory, I/O, screen and keyboard.)
void	load(BaseLoader loader) Load the Spectrum contents from the given loader, by calling the load() method of all contained components.
void	pause() Pause the emulation (asynchronous).
void	reset() Reset all contained references (CPU, memory, I/O, screen and keyboard.)
void	setFrequency(long frequency) Set the frequency used by the m_clock.
void	setScale(int scale) Trivial mutator for the scale parameter of this Spectrum.
void	stop() Stop the emulation (asynchronous.)
void	terminate() Terminate all contained references (CPU, memory, I/O, screen and keyboard) and subsequently set them to null.
void	unpause() Unpause the emulation (asynchronous).
void	update()

Methods inherited from class org.razvan.jzx.BaseComponent

getSpectrum

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

FREQUENCY_MS

public static final long FREQUENCY_MS

The 20ms frequency of the interrupt clock. NOTE: This is set to 19 (instead of 20) because many games are frame-synchronized, and if they miss a screen refresh even by a little they wait until the next one. This means that roughly one out of two times, they will wait a frame too long. This effectively reduces the framerate by 50% to around 30FPS. By setting the frequency to 19, we guarantee that an interrupt will have arrived by the next frame, so the effective framerate is around 50FPS.

See Also:

Constant Field Values

ISSUE_2

public static final int ISSUE_2

48k Spectrum model 2 (issue 2)

See Also:

Constant Field Values

ISSUE_3

public static final int ISSUE_3

48k Spectrum model 3 (issue 3)

See Also:

Constant Field Values

m_status

protected java.awt.Label m_status

Label used to display various status messages.

m_cpu

protected Z80 m_cpu

Contained reference to the Z80 CPU.

m_memory

protected BaseMemory m_memory

Contained reference to the memory object.

m_io

protected BaseIO m_io

Contained reference to the I/O object.

m_screen

protected BaseScreen m_screen

Contained reference to the screen object.

m_container

protected java.awt.Container m_container

Component that decorates the screen object for display in a Frame, Applet, etc.

m_keyboard

protected BaseKeyboard m_keyboard

Contained reference to the keyboard object.

m_clock

protected Clock m_clock

The interrupt clock.

m_frequency

protected long m_frequency

m_issue

protected int m_issue

The model (issue) of this Spectrum.

m_vline

protected int m_vline

The current vertical line being drawn.

m_scale

protected int m_scale

The current scale value for this Spectrum.

This value is retrieved by the screen object during its init() phase.

m_tvLines

protected int m_tvLines

The number of lines per TV frame.

This value is different for the different Spectrum models.

m_cyclesLine

protected int m_cyclesLine

The number of CPU T-States per TV line.

This value is different for the different Spectrum models.

Constructor Detail

BaseSpectrum

public BaseSpectrum()

Method Detail

init

public void init(BaseSpectrum spectrum,
                 ILogger logger)

Allocate the clock object, and initialize all contained references (CPU, memory, I/O, screen and keyboard.)

Overrides:

init in class BaseComponent

reset

public void reset()

Reset all contained references (CPU, memory, I/O, screen and keyboard.)

Specified by:

reset in class BaseComponent

terminate

public void terminate()

Terminate all contained references (CPU, memory, I/O, screen and keyboard) and subsequently set them to null.

Overrides:

terminate in class BaseComponent

getIssue

public int getIssue()

Trivial accessor for the issue (model) of this Spectrum.

getScale

public int getScale()

Trivial accessor for the scale parameter of this Spectrum.

This method is called by the screen object in its init() method.

setScale

public void setScale(int scale)

Trivial mutator for the scale parameter of this Spectrum.

getVline

public int getVline()

Trivial accessor for the current TV line being drawn.

getFrequency

public long getFrequency()

Get the frequency used by the m_clock.

Returns:

The clock frequency, in milliseconds

setFrequency

public void setFrequency(long frequency)

Set the frequency used by the m_clock.

Parameters:

frequency - The clock frequency, in milliseconds

getCPU

public Z80 getCPU()

Trivial accessor for this Spectrum's CPU.

getMemory

public BaseMemory getMemory()

Trivial accessor for this Spectrum's memory.

getIO

public BaseIO getIO()

Trivial accessor for this Spectrum's I/O.

getScreen

public BaseScreen getScreen()

Trivial accessor for this Spectrum's screen.

getContainer

public java.awt.Component getContainer()

Return a Container that decorates the Spectrum screen and adds other UI elements such as a status bar.

getKeyboard

public BaseKeyboard getKeyboard()

Trivial accessor for this Spectrum's keyboard.

getMode

public abstract java.lang.String getMode()

String that describes the type of Spectrum ("48", "128").

emulate

public void emulate()

The main emulator loop.

The steps performed are as follows:

• Start the clock.
• Repeat until stopped:
• If the current CPU T-States is more than the number of cycles per line, increment the number of lines.
• If the number of lines is greater than the number of lines per frame:
• If this is the 25th frame (twice per second) toggle the flash.
• Refresh the current screen frame.
• Wait for the next CPU interrupt.
• Decode and execute the next CPU instruction.

update

public void update()

pause

public void pause()

Pause the emulation (asynchronous).

unpause

public void unpause()

Unpause the emulation (asynchronous).

stop

public void stop()

Stop the emulation (asynchronous.)

load

public void load(BaseLoader loader)

Load the Spectrum contents from the given loader, by calling the load() method of all contained components.

Specified by:

load in class BaseComponent