TweetFollow Us on Twitter

Pearl Lisp
Volume Number:6
Issue Number:8
Column Tag:Programmer's Workshop

Objects in Pearl Lisp

By Stephan E. Miner, Menlo Park, CA

As a software engineer in the Information Sciences and Technology Center at SRI International, Steve Miner works on applied research in artificial intelligence, particularly in the areas of planning and decision aids. SRI’s hardware environment consists mainly of Sun workstations and Symbolics Lisp Machines, but Steve gets to use a Macintosh SE at home.

Introduction

Coral Software recently released Pearl Lisp, a subset of Common Lisp for about $100. Pearl Lisp is based on Coral’s Allegro Common Lisp which has been discussed in an earlier issue of MacTutor (see Paul Snively’s article in the March 1988 issue.) Although Allegro received very good reviews, its list price of about $600 made it impractical for most first-time Lisp programmers. Pearl Lisp offers an affordable introduction to Lisp programming on the Macintosh.

Although a complete review of Pearl Lisp is not the purpose of this article, a brief overview might be helpful. Some features of Common Lisp (such as packages, structures, hash tables and multiple values) are not supported. However, most of the list, control, and mathematical functions of Common Lisp are available. Lexical scoping and closures are also implemented. The development environment is very much like Allegro’s and includes an EMACS-like editor known as FRED (FRED Resembles EMACS Deliberately.) The reference manual is well-written, with cross references to Steele’s Common LISP: the Language and several popular textbooks. In addition to the subset of Common Lisp functions, Pearl Lisp includes a native object-oriented programming system, called Object Lisp, which is the topic of this article.

As a demonstration of Object Lisp, the sample program simulates a solar system. Objects are used to implement the planets as well as the Macintosh windows and menus. Each planet orbits around a gravitational center at some radius with a certain period. At any point in time, the planet has some X and Y coordinates relative to the center of the solar system. The simulation is displayed in various windows with each window offering the view from a particular planet. For example, a heliocentric view has the Sun appearing fixed at the center of the window. In contrast, a geocentric view keeps the Earth at the center of display with some of the other planets showing retrograde motion. In both cases, the same planets are used and they maintain the same relative motions. It is the window objects which implements the different points of view.

Object Lisp

Before describing the sample program in detail, a brief introduction to the basic concepts of Object Lisp will be presented. As in other object-oriented programming systems, an object encapsulates both data and functions. An object’s data is contained in internal variables, known as instance variables. (Instance variables are often called slots in other systems.) An object can also have specialized object functions that allow access to the object’s internal variables as if the internal variables were local to the function. (Object functions are often called methods in other object-oriented systems.)

Inheritance is another key concept in most object-oriented systems. In Object Lisp, objects are defined in terms of other objects. An object inherits the instance variables and object functions of its parents. (Object Lisp supports multiple inheritance, but the details are not discussed in this article.) An object can replace, specialize, or combine the characteristics of its parents by shadowing the appropriate object functions. A parent’s object function foo is also accessible by calling usual-foo, even when the parent’s object function is shadowed.

The special form ask is used to access the environment of an object. For example, suppose that OBJECT is bound to some object. The form (ASK OBJECT VAR) will return the object’s internal value for VAR. The form (ASK OBJECT (FUNC ‘ARG)) will return the result of calling the object function FUNC with the argument ‘ARG.

Conceptually, global variables and functions belong to the root object nil. Thus, (ASK NIL (GLOBAL-FUNC ‘ARG)) is equivalent to (GLOBAL-FUNC ‘ARG). This also implies that global variables and functions are accessible by all objects through inheritance from the root object. The root object also implements several useful object functions. The have object function is used to create instance variables. For example, (ASK OBJECT (HAVE ‘VAR ‘VAL)) will create an instance variable VAR with an initial value VAL for the object OBJECT. The self object function simply returns the current object.

Classes

Most object-oriented systems make a distinction between a class and an instance. A class defines a type of object with a description of its internal data and the associated procedures (or methods) for operating on that data. An instance, on the other hand, is a specific object with internal values which hold its state. Object Lisp does not enforce this strict distinction, but it does support a convention that implements classes as types of objects.

Class objects can be created with the macro defobject which defines the name of the class and the parents from which it inherits. Nil is used as the root object class.

An instance of a class is created by the function oneof which takes the parent class as the first argument, followed by a list of keyword-value pairs for initializing the instance. The initialization is actually executed by the exist object function defined for the class. We will see how the exist object function works in our sample program.

The Solar Program

The sample program can be divided into three major sections. The first part implements the planet class. Window objects are implemented by the second part. The final section provides menus for controlling the execution of the program.

The *planet* class is quite simple. It is defined using defobject and inherits only from the root class object, nil.

The exist object function for *planet* needs more explanation. Exist will be called automatically by the system when the oneof function is used to create a new instance of*planet*. The init-list argument will be a list of the keyword-value pairs given to oneof. The main purpose of the exist object function is to initialize the instance variables. The getf function is used to access the value associated with the indicated keyword. A default value can also be specified in case the keyword is not found. For example, if the period of a planet is not specified in the init-list, the default value of 25 is used.

In order to simplify the creation of new planets, the :center keyword is used to specify the orbital center of the new planet. When calculating coordinates, however, it is more natural to proceed from the center out to the satellites. The center is asked to add the new planet to the its list of satellites using the add-satellite object function.

The update-system object function calculates the new X and Y coordinates for the planet given the time and the coordinates of the planet’s orbital center. The planet then recursively asks its satellites to run update-system. Thus, a single update-system call to the sun of a solar system will be propagated through all the planets in the system.

The other class that the program defines is the *solar-window*. This class is a specialized version of the *window* class which is provided by Coral as an interface to the Macintosh window system. This is a good example of how one can easily extend a previously defined class. In this case, the new exist first calls usual-exist to handle the normal initialization of the window. The init-list-default function returns an init-list with the additional defaults. *Solar-window* also has a couple of its own instance variables. The center instance variable determines the gravitational center of the solar system (normally the *sun*.) The view instance variable controls the viewpoint of the display. For example, a geocentric view is given by setting the view to *earth*.

The center-origin object function resets the origin of the window to the center of view. This simplifies the display of the solar system. The window-zoom-event-handler and set-window-size object functions are also extended to recenter the origin.

The inheritedwindow-show object function displays the window on the screen. This indirectly calls the window-draw-contents object function. The sample program does not worry too much about animation flicker so it simply erases the entire window and then redraws everything. The usual-window-draw-contents takes care of redrawing the grow box.

The draw-system object function does most of the work. Its structure is similar to update-system in that it draws one planet and then recursively draws the satellites of that planet. In this case, however, the x-off and y-off arguments are offsets that are added to the absolute coordinates for the planet to determine the planet’s window coordinates. Each view assigns offsets so that the view planet remains centered in the window. The rlet macro lets a Lisp program create Pascal record structures, such as those used by the Macintosh ROM routines. Here, a rectangle is initialized based on the size of the planet and its window coordinates. The Quickdraw routines, fill-oval and frame-oval, are used to draw the planet. When rlet exits, the temporary record is disposed automatically.

The erase-window object function also accesses a Pascal record structure. In this case, it uses the rref macro to return the window’s portrect. The instance variable, wptr, is defined by the *window* class and holds a Macintosh window pointer. Rref allows the Lisp program to access the fields of the record using a Pascal-style notation. The window is erased by calling the Quickdraw function erase-rect.

The final section of the sample program involves the menu system. Once again, the menus and menu items are predefined classes of objects. A menu-item-action function is associated with each menu item. This function is called when the user selects the item.

The ubiquitous main event loop is implemented by the Pearl Lisp event system and its interface to the Macintosh operating system. It is important to note that the event system will interrupt the normal Lisp read-eval-print loop in order to run event handlers. Menus and dialogs can take advantage of this behavior by using the eval-enqueue function. Eval-enqueue queues the given form in the Lisp system’s read-eval-print loop for execution after the event handler exits. This allows the user to interact freely with the program while it is executing. The programmer is also freed from writing his own main event loop since the object system will call the appropriate handlers as needed.

In the sample program, the first three menu items create three different views of the solar system. Each item calls the new-solar function to create a new solar window with the appropriate view planet. The window title includes a number for easy reference. The program has no limit on the number of windows that it can display.

The *run-item* uses eval-enqueue to enqueue a call to the run-loop function. Run-loop maintains the checkmarks on the menu items and runs the simulations. On each pass through the loop, the global variable*time* is incremented, and the *sun* is asked to update-system for the new time. (This updates the locations of all the planets in the solar system.) Then each window is asked to redraw itself to reflect the new positions of the planets. The (ownp ‘wptr) test makes sure that the window still exists and protects against the user having closed the window while the loop was executing. Run-loop exits when the *stop-flag* is set or the window list is empty.

The *stop-item* action immediately sets the *stop-flag* during the execution of the handler. This action will interrupt the execution of the run-loop function which will later exit as soon as it rechecks the flag. The *exit-item* is similar but also enqueues a call to exit-solar which will execute after the run-loop function terminates. The exit-solar function then quits the demonstration by gathering a list of all *solar-window* objects and asking each of them to close-window (which is inherited from *window*.) Close-window also takes care of disposing of the window structure.

Conclusion

This article has presented an introduction to object-oriented programming in Pearl Lisp. The sample program demonstrates how the object system simplifies programming with windows and menus in Lisp. Without any extra work, the program also runs in the background under MultiFinder. The included screen shot shows how the program conveniently integrates with the Pearl Lisp environment.

;;; Sample program for "Objects in Pearl Lisp"
;;; by Stephen E. Miner
;;; Written in Pearl Lisp 1.01
;;; File:  Solar.lisp
;;; Version: 1.0

;;; NOTE:  The "object-variable" declarations prevent the ;;;compiler 
from issuing warnings about free variables.

;;; Set up environment
(eval-when (eval load compile)
  (require 'quickdraw))
(eval-when (eval compile)
  (require 'records))

;;; Global variables
(defvar *solar-num* 0 "Global counter for numbering windows.")
(defvar *time* 0 "Global variable holding the time that is     displayed.")
(defvar *stop-flag* t "Non-nil if simulation should stop.")

;;; The planet class
(defobject *planet* nil)

(defobfun (exist *planet*) (init-list)
  "Initializes an instance of the *planet* class according to INIT-LIST. 
 Useful init keywords are :period, :size, :pattern, :radius and :center. 
 The return value is undefined."
  (have 'period (getf init-list :period 25))
  (have 'size (getf init-list :size 3))
  (have 'pattern (getf init-list :pattern *black-pattern*))
  (have 'x 0)
  (have 'y 0)
  (have 'satellites nil)
  (let ((center (getf init-list :center))
           (me (self))) ;(self) returns object being defined
      (have 'radius (getf init-list :radius (if center 25 0)))
      (when center
         (ask center (add-satellite me)))))

(defobfun (add-satellite *planet*) (sat)
  "Add SAT to the planet's list of satellites and return the new list."
  (declare (object-variable satellites))
  (setq satellites (cons sat satellites)))
 
(defobfun (update-system *planet*) (time cx cy)
  "Update the x and y coordinates of the planet according to the TIME 
and the offsets CX and CY which should be the x and y coordinates of 
the center of the planet's orbit.  Then recursively send the update-system 
message to the satellites of the planet using the new x and y coordinates 
as the offsets.  The return value is undefined." 
  (declare (object-variable period radius x y satellites))
  (let* ((theta (* 2 pi (/ time period)))
             (new-x (+ cx (round (* radius (cos theta)))))
             (new-y (+ cy (round (* radius (sin theta))))))
      (setq x new-x y new-y)
      (dolist (sat satellites)
          (ask sat (update-system time new-x new-y)))))

;;; The planet objects (the numbers are not accurate, but they 
;;; produce a reasonable display.)
(defparameter *sun* (oneof *planet* :center nil :size 11 
                           :pattern *light-gray-pattern*))
  
(defparameter *mercury* (oneof *planet* :radius 20 :center     *sun* 
:period 12  :size 3 :pattern  *dark-gray-pattern*))

(defparameter *venus* (oneof *planet* :radius 35 :center       *sun* 
:period 32 :size 5 :pattern *dark-gray-pattern*))

(defparameter *earth* (oneof *planet* :radius 60 :center *sun* 
 :period 52 :size 6 :pattern *gray-pattern*))

(defparameter *moon* (oneof *planet* :radius 10 :center  *earth* :period 
4  :size 2))

(defparameter *mars* (oneof *planet* :radius 85 :center *sun*  :period 
90 :size 5 :pattern *dark-gray-pattern*))

;;; The solar window class
(defobject *solar-window* *window*)

(defobfun (exist *solar-window*) (init-list)
  "Initializes an instance of the *solar-window* according to the INIT-LIST. 
 Useful keywords are :center which specifies the gravitational center 
of the displayed system and :view which specifies the planet that controls 
the viewpoint of the display.  The return value is undefined."
  (declare (object-variable center))
  (usual-exist (init-list-default init-list 
                                  :window-title "Solar System"
                                  :window-size #@(250 250)
                                  :window-show nil))
  ;;don't show window until the window is fully initialized
  (have 'center (getf init-list :center))
  (have 'view (getf init-list :view center))
  (center-origin)
  (window-show))

;;; The event system will automatically ask windows to handle 
;;; certain events.  Specialized object functions for handling 
;;; these events are defined below.
(defobfun (window-draw-contents *solar-window*) ()
  "Specialized version of window-draw-contents called by the event system 
whenever part of the window needs to be redrawn.  The return value is 
undefined."
  (declare (object-variable center view x y))
  (erase-window)
  (usual-window-draw-contents)
  (draw-system center (- (ask view x)) (- (ask view y))))

(defobfun (window-zoom-event-handler *solar-window*) (message)
  "Specialized version of window-zoom-event-handler which is called by 
the operating system when the user clicks in the zoom box.  The MESSAGE 
is passed on to the usual-window-zoom-event-handler.  This version also 
recenters the origin.  The return value is undefined."
  (usual-window-zoom-event-handler message)
  (center-origin))

(defobfun (set-window-size *solar-window*) (h &optional v)
  "Specialized version of set-window-size.  Sets the size of the window 
according to horizontal and vertical dimensions, H and V.  H and V are 
either two integers or H is taken as a point if V is nil.  Also recenters 
the origin and redraws the window.  Returns the window's new size as 
a point."
  (prog1
    (usual-set-window-size h v)
    (center-origin)
    (window-draw-contents)))

(defobfun (center-origin *solar-window*) ()
  "Adjust the origin to the center of the window.  Returns the window's 
new upper lefthand corner as a point."
  (let ((pt (window-size)))
    (set-origin (floor (point-h pt) -2)
                (floor (point-v pt) -2))))

(defobfun (draw-system *solar-window*) (planet x-off y-off)
  "Draw the PLANET and its satellites in the window after adding X-OFF 
and Y-OFF to the planet's x and y coordinates.  The return value is undefined."
  (declare (object-variable x y size pattern satellites))
  (let ((x0 (+ (ask planet x) x-off))
        (y0 (+ (ask planet y) y-off))
        (size (ask planet size)))
    ;;allocate a temporary rectangle for graphics calls
    (rlet ((rec :rect :top (- x0 size) :left (- y0 size)
                :bottom (+ x0 size) :right (+ y0 size)))
      (fill-oval (ask planet pattern) rec)
      (frame-oval rec)))
  ;;draw the satellites
  (dolist (sat (ask planet satellites))
    (draw-system sat x-off y-off)))

(defobfun (erase-window *solar-window*) ()
  "Erase the contents of the window.  The return value is undefined."
  ;;rref access the Macintosh record and in this case returns 
  ;; the window's portrect.  See the Pearl Lisp documentation 
  ;; for more information about records.
  (declare (object-variable wptr))
  (erase-rect (rref wptr window.portrect)))

;;; Menu action functions
(defun new-solar (view-planet title)
  "Create a new solar window with VIEW-PLANET determining the point of 
view and the TITLE string used as base for the window title.  The global 
*solar-num* is incremented and appended to the window title to ease identification. 
 Returns the new window object."
  (setq *solar-num* (+ *solar-num* 1))
  (oneof *solar-window* :window-title 
         (format nil "~A ~A" title *solar-num*)
         :center *sun*
         :view view-planet))

(defun exit-solar ()
  "Close all the solar windows and deinstall the menu.  The return value 
is undefined."
  (dolist (w (windows *solar-window*)) 
    (ask w (window-close)))
  (ask *solar-menu* (menu-deinstall)))

(defun run-loop ()
  "Run the simulation until the global *stop-flag* is true.  This function 
also manages the solar menu."
  (setq *stop-flag* nil)
  (ask *stop-item* (set-menu-item-check-mark nil))
  (ask *run-item* (set-menu-item-check-mark t))
  (loop
    (let ((wlist (windows *solar-window*))) 
           ;;list of all *solar-window*'s
      (when (or *stop-flag* (null wlist))   
       ;;check for end of simulation
        (ask *run-item* (set-menu-item-check-mark nil))
        (ask *stop-item* (set-menu-item-check-mark t))
        (return))
      (setq *time* (+ 1 *time*))
      (ask *sun* (update-system *time* 0 0)) 
      ;;updates all the x and y coords
      (dolist (w wlist)
        (ask w (when (ownp 'wptr)   ;protect against close-box
            (window-draw-contents)))))))   ;redraw the window

;;; The menu items
(defparameter *new-helio-item* 
  (oneof *menu-item* :menu-item-title "New Helio"
         :menu-item-action '(new-solar *sun* "Heliocentric")))

(defparameter *new-geo-item* 
  (oneof *menu-item* :menu-item-title "New Geo"
         :menu-item-action '(new-solar *earth* "Geocentric")))

(defparameter *new-luna-item* 
  (oneof *menu-item* :menu-item-title "New Luna"
         :menu-item-action '(new-solar *moon* "Lunacentric")))

(defparameter *run-item* 
  (oneof *menu-item* :menu-item-title "Run"
         :menu-item-action '(when *stop-flag* 
                             (eval-enqueue '(run-loop)))))
                    
(defparameter *stop-item* 
  (oneof *menu-item* :menu-item-title "Stop"
         :menu-item-action '(setq *stop-flag* t)))

(defparameter *exit-item* 
  (oneof *menu-item* :menu-item-title "Exit"
         :menu-item-action 
         '(progn
            (setq *stop-flag* t)
            (eval-enqueue '(exit-solar)))))
;;The eval-enqueue makes sure that we wait for the run-loop to 
;; finish before we exit.

(defparameter *solar-menu* 
  (oneof *menu* :menu-title "Solar"
         :menu-items (list *new-helio-item*
                           *new-geo-item*      
                           *new-luna-item*
                           (oneof *menu-item* :menu-item-title "-":disabled 
t)
                           *run-item*
                           *stop-item*
                           *exit-item*)))

;;; Install the menu
(ask *run-item* (set-menu-item-check-mark (not *stop-flag*)))
(ask *stop-item* (set-menu-item-check-mark *stop-flag*))
(ask *solar-menu* (menu-install))

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Deeper 2.2.1 - Enable hidden features in...
Deeper is a personalization utility for macOS which allows you to enable and disable the hidden functions of the Finder, Dock, QuickTime, Safari, iTunes, login window, Spotlight, and many of Apple's... Read more
Spotify 1.0.59.395. - Stream music, crea...
Spotify is a streaming music service that gives you on-demand access to millions of songs. Whether you like driving rock, silky R&B, or grandiose classical music, Spotify's massive catalogue puts... Read more
FileZilla 3.27.0.1 - Fast and reliable F...
FileZilla (ported from Windows) is a fast and reliable FTP client and server with lots of useful features and an intuitive interface. Version 3.27.0.1: MSW: Add misssing file to .zip binary package... Read more
Sierra Cache Cleaner 11.0.6 - Clear cach...
Sierra Cache Cleaner is an award-winning general purpose tool for macOS X. SCC makes system maintenance simple with an easy point-and-click interface to many macOS X functions. Novice and expert... Read more
Live Home 3D Pro 3.1.2 - $69.99
Live Home 3D Pro, a successor of Live Interior 3D, is the powerful yet intuitive home design software that lets you build the house of your dreams right on your Mac. It has every feature of Live Home... Read more
Pinegrow 3.04 - Mockup and design webpag...
Pinegrow (was Pinegrow Web Designer) is desktop app that lets you mockup and design webpages faster with multi-page editing, CSS and LESS styling, and smart components for Bootstrap, Foundation,... Read more
DiskCatalogMaker 7.1.2 - Catalog your di...
DiskCatalogMaker is a simple disk management tool which catalogs disks. Simple, light-weight, and fast Finder-like intuitive look and feel Super-fast search algorithm Can compress catalog data for... Read more
Apple iTunes 12.6.2 - Play Apple Music a...
Apple iTunes lets you organize and stream Apple Music, download and watch video and listen to Podcasts. It can automatically download new music, app, and book purchases across all your devices and... Read more
Transmit 5.0 - Excellent FTP/SFTP client...
Transmit is an excellent FTP (file transfer protocol), SFTP, S3 (Amazon.com file hosting) and iDisk/WebDAV client that allows you to upload, download, and delete files over the internet. With the... Read more
Adobe Lightroom 6.12 - Import, develop,...
Adobe Lightroom is available as part of Adobe Creative Cloud for as little as $9.99/month bundled with Photoshop CC as part of the photography package. Lightroom 6 is also available for purchase as a... Read more

Latest Forum Discussions

See All

The best deals on the App Store this wee...
There are quite a few truly superb games on sale on the App Store this week. If you haven't played some of these, many of which are true classics, now's the time to jump on the bandwagon. Here are the deals you need to know about. [Read more] | Read more »
Realpolitiks Mobile (Games)
Realpolitiks Mobile 1.0 Device: iOS Universal Category: Games Price: $5.99, Version: 1.0 (iTunes) Description: PLEASE NOTE: The game might not work properly on discontinued 1GB of RAM devices (iPhone 5s, iPhone 6, iPhone 6 Plus, iPad... | Read more »
Layton’s Mystery Journey (Games)
Layton’s Mystery Journey 1.0.0 Device: iOS Universal Category: Games Price: $15.99, Version: 1.0.0 (iTunes) Description: THE MUCH-LOVED LAYTON SERIES IS BACK WITH A 10TH ANNIVERSARY INSTALLMENT! Developed by LEVEL-5, LAYTON’S... | Read more »
Full Throttle Remastered (Games)
Full Throttle Remastered 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: Originally released by LucasArts in 1995, Full Throttle is a classic graphic adventure game from industry legend Tim... | Read more »
Stunning shooter Morphite gets a new tra...
Morphite is officially landing on iOS in September. The game looks like the space shooter we've been needing on mobile, and we're going to see if it fits the bill quite shortly. The game's a collaborative effort between Blowfish Studios, We're Five... | Read more »
Layton's Mystery Journey arrives to...
As you might recall, Layton's Mystery Journey is headed to iOS and Android -- tomorrow! To celebrate the impending launch, Level-5's released a new trailer, complete with an adorable hamster. [Read more] | Read more »
Sidewords (Games)
Sidewords 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Grab a cup of coffee and relax with Sidewords. Sidewords is part logic puzzle, part word game, all original. No timers. No... | Read more »
Noodlecake Games' 'Leap On!...
Noodlecake Games is always good for some light-hearted arcade fun, and its latest project, Leap On! could carry on that tradition. It's a bit like high stakes tetherball in a way. Your job is to guide a cute little blob around a series of floating... | Read more »
RuneScape goes mobile later this year
Yes, RuneScape still exists. In fact, it's coming to iOS and Android in just a few short months. Jagex, creators of the hit fantasy MMORPG of yesteryear, is releasing RuneScape Mobile and Old School RuneScape for mobile devices, complete with... | Read more »
Crash of Cars wants you to capture the c...
Crash of Cars is going full on medieval in its latest update, introducing castles and all manner of new cars and skins fresh from the Dark Ages. The update introduces a new castle-themed map (complete with catapults) and a gladiator-style battle... | Read more »

Price Scanner via MacPrices.net

Save or Share
FotoJet Designer, is a simple but powerful new graphic design apps available on both Mac and Windows. With FotoJet Designer’s 900+ templates, thousands of resources, and powerful editing tools you... Read more
Logo Maker Shop iOS App Lets Businesses Get C...
A newly released app is designed to help business owners to get creative with their branding by designing their own logos. With more than 1,000 editable templates, Logo Maker Shop 1.0 provides the... Read more
Sale! New 15-inch MacBook Pros for up to $150...
Amazon has the new 2017 15″ MacBook Pros on sale for up to $150 off MSRP including free shipping: – 15″ 2.8GHz MacBook Pro Space Gray: $2249 $150 off MSRP – 15″ 2.89Hz MacBook Pro Space Gray: $2779 $... Read more
DEVONthink To Go 2.1.7 For iOS Brings Usabili...
DEVONtechnologies has updated DEVONthink To Go, the iOS companion to DEVONthink for Mac, with enhancements and bug fixes. Version 2.1.7 adds an option to clear the Global Inbox and makes the grid... Read more
15-inch 2.2GHz Retina MacBook Pro, Apple refu...
Apple has Certified Refurbished 2015 15″ 2.2GHz Retina MacBook Pros available for $1699. That’s $300 off MSRP, and it’s the lowest price available for a 15″ MacBook Pro. An Apple one-year warranty is... Read more
13-inch 2.3GHz Silver MacBook Pro on sale for...
B&H Photo has the new 2017 13″ 2.3GHz/256GB Silver MacBook Pro (MPXU2LL/A) on sale for $1399 including free shipping plus NY & NJ sales tax only. Their price is $100 off MSRP. Read more
Apple Tackles Distracted Driving With iOS 11...
One of the most important new features coming in iOS 11 is Do Not Disturb while driving, intended to help drivers stay more focused on the road. With Do Not Disturb while driving, your iPhone can... Read more
iMazing Mini for Mac: Free Automatic and Priv...
Geneva, Switzerland-based indie developer DigiDNA has released iMazing Mini, their free macOS utility designed to automatically back up iOS devices over any local Wi-Fi network. The app offers users... Read more
Clearance 2016 13-inch MacBook Airs, Apple re...
Apple dropped prices recently on Certified Refurbished 2016 13″ MacBook Airs, with models now available starting at $809. An Apple one-year warranty is included with each MacBook, and shipping is... Read more
9.7-inch 2017 iPads available for $299, save...
B&H Photo has 2017 9.7″ 32GB WiFi iPads on sale for $30 off MSRP for a limited time. Shipping is free, and pay sales tax in NY & NJ only: – 32GB iPad WiFi: $299, $30 off Read more

Jobs Board

Senior Payments Architect - *Apple* Pay - A...
Changing the world is all in a day's work at Apple . If you love innovation, here's your chance to make a career of it. You'll work hard. But the job comes with more Read more
Frameworks Engineering Manager, *Apple* Wat...
Frameworks Engineering Manager, Apple Watch Job Number: 41632321 Santa Clara Valley, California, United States Posted: Jun. 15, 2017 Weekly Hours: 40.00 Job Summary Read more
Manager, *Apple* Media Products - Apple Inc...
Job Summary The Apple Media Products Discovery, Fraud and Abuse team is responsible for protecting the integrity of Apple services. As a manager of the team, you Read more
*Apple* Watch, Accessories, Engineering Proj...
Job Summary Engineering Project Manager, Apple Watch Accessories. The Accessories group is looking for an Engineering Project Manager (EPM) to lead the design and Read more
Sr. Technical Writer - *Apple* Information...
Changing the world is all in a day's work at Apple . If you love innovation, here's your chance to make a career of it. You'll work hard. But the job comes with more Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.