Back to the Future for Computers

The return of the “bicycle for our minds”.

Sinclair Research ZX Spectrum 48K

Sinclair Research ZX Spectrum

What happened to the computer? If you are old enough to remember the 1980’s you may recall the explosion of home computers that occured, some of the most popular being:

  • Sinclair Research’s ZX80, ZX81 and Spectrum.
  • Commodore Business Machines VIC-20, Commodore 64 and Amiga.
  • Atari’s 400, 800 and ST.
  • Acorn Computers BBC Micro, Electron and Archimedes
  • Apple IIe
A Simple Basic Program on an Atari Screen

A Simple Basic Program

Unlike the video games consoles (such as the Atari 2600) not only could these systems be used to play games they could also be programmed, usually in Beginner’s All-purpose Symbolic Instruction Code (BASIC). These easy to use computers provided many with the education needed to forge successful careers and build successful businesses in the new Information Technology industry that emerged in the 1990’s as the Internet sprang into life. What was great about these computers was the immediacy, intimacy, responsiveness and quick boot time. It was only seconds from turning the power on to starting to type a computer program. A computer program that could easily access the raw hardware of the computer. Unlike the typical computers purchased on the high street today, which are over engineered, power hungry, bloated and slow booting devices. So despite a quarter of a century of technological advances how did we end up with expensive devices that kids cannot easily program. Continue reading

Example List of Android Device Screen Resolutions and Sizes

The success of Android as a mobile device Operating System (OS) has resulted in a large variety of screen sizes and resolutions. Here is provided a list of example devices to show that variation.

Portrait v LandscapeIn the following table it is assumed that the device is held in portrait orientation. As such the width in pixels is the X-axis and the length or height in pixels is the Y-axis. Obviously that swaps when the device is held in landscape orientation. Android has support for both orientations so that a correctly programmed App will work no matter which way you hold the device. If you need to understand about pixels see the article How Computer Screens and Printers Show Images. The total number of pixels in a screen is the number in the x-axis multiplied by the number in the y-axis. The more pixels for each square inch (or centimetre) of display the sharper any images will be displayed (provided those images are at a high resolution).

For an explanation of the Acronym see the article Screen Resolution Names. The Size column next to each device is the diagonal measurement for the device screen in inches. This table illustrates that screens with the same resolution can be different sizes.

Example Andriod Screen Sizes and Resolutions
# Pixels X Y ACRONYM Device Example 1 Size Device Example 2 Size
76800 240 320 QVGA ZTE Tureis 2.6 Samsung Galaxy Fit (GT-S5670 ) 3.3
96000 240 400 WQVGA400 Samsung Galaxy Apollo 3.2 Archos 32 Internet Tablet 3.2
153600 320 480 HVGA HTC ChaCha 2.6 HTC Explorer 3.2
230400 360 640 nHD Dell Aero 3.5 Dell Mini 3ix 3.5
307200 480 640 VGA Motorola Pro+ MB632 3.1 Motorola Admiral 3.1
384000 480 800 WVGA800 Google Nexus One 3.7 Dell Streak 7 7
409920 480 854 WVGA854 Sony Xperia Ray 3.3 Archos 43 Internet Tablet 4.3
480000 600 800 SVGA Elonex eTouch 702ET 7 Pandigital SuperNova 8
491520 480 1024 UWVGA Acer Iconia Smart S300 4.8 Sony Tablet P 5.5
518400 540 960 qHD Motorola Atrix 4 HTC Vivid 4.5
614400 640 960 DVGA Sharp IS03 3.5 iPhone 4S 3.5
614400 600 1024 WSVGA Amazon Kindle Fire 7 Archos 101 Internet Tablet 10.1
786432 768 1024 XGA Archos 80 G9 8 Malata T8 9.7
921600 720 1280 WXGA720, HD, 720p Galaxy Nexus (GT-i9250) 4.6 Sony Xperia S 4.3
983040 768 1280 WXGA Ramos W15 8 LG Optimus PAD (V900) 8.9
1024000 800 1280 WXGA800 Samsung Galaxy Note (GT-N7000) 5.3 Motorola Xoom 2 10.1

The iPhone 4S is shown in the table for comparision purposes, see the DVGA line, it is not an Android phone. Note a Full High Definition (FHD) or 1080i/1080p screen is 1080×1920 which is 2,073,600 pixels. Despite the wide variation in resolutions and screen sizes the Android OS and its Software Development Kit (SDK) caters for all of them.