Scratch Built Revolution Pdf 19
Siri Vonbank
The Altair 8800, introduced in the early 1970s, was the first computer you could build at home from a kit. It was crude, didn't do much, but many historians would say that it launched the desktop computer revolution.
Such machines could evolve from the 3-D printers currently used by industrial engineers for "rapid prototyping." They design parts in computer-aided design programs and feed the designs to 3-D printers to make working plastic models. A 3-D printer has a small nozzle that scans back and forth across a surface, depositing tiny droplets of quick-hardening plastic. After each scan, the nozzle moves up a notch and scans again until it has built up the complete object, layer by layer. With multiple nozzles or a means of swapping supply cartridges, the machine can create objects made of many different materials. An electronic circuit, for example, can be made by combining an organic semiconductor, metallic inks and ceramic insulators.
So far, Lipson says, about a dozen people have said they are building one, and he knows of three that are actually up and running -- two at the University of Washington and one in Innsbruck, Austria. Lipson's group has built several and lent a couple to other researchers.
Future fabbing machines will have to shift from one raw material to another in midstream and probably deposit material in three dimensions, not just layers, says Lipson. Research in his lab is taking early steps. Malone has built a machine that uses a rack of interchangeable cartridges to make devices out of several materials at once. So far, it has made a working battery, complete with outer case. Malone's long-range goal is to "print" a complete robot, including limbs, actuators, control circuitry and batteries.
Learning physics problems still appear in many parts of the world. Along with this, the development of civilization demands the development of education to produce the skills that are the ultimate in every human being. 21st Century skills are skills that are relevant to the demands of the development of civilization. Pre-service Teacher needs to be prepared to overcome the problems of learning Physics by following with the times. This study aims to develop a skill-oriented Momentum teaching material of the 21st Century and the industrial revolution. This research is development research with stages: 1) Analysis of potential and problems, 2) Product design, 3) Design validation and design revision, 4) Product testing, 5) Analysis of trial results, and 6) final product assembly. The research instruments were in the form of observation sheets, tests, and questionnaires. The data analysis technique uses descriptive percentages. The results of the study in the form of scratch-assisted teaching materials that have characteristics provide opportunities for students to make momentum simulations independently. The percentage of the material validity score was 92.23% and the media validity was 88.64%. The results of the trial show that the acquisition of each skill score is more than 71, so it can be concluded that the materials teaching developed are practically used and effective to build 21st-century skills and industrial revolution 4.0.
Home computers were usually sold already manufactured in stylish metal or plastic enclosures. However, some home computers also came as commercial electronic kits, like the Sinclair ZX80, which were both home and home-built computers since the purchaser could assemble the unit from a kit.
While two early home computers (Sinclair ZX80 and Acorn Atom) could be bought either in kit form or assembled, most home computers were only sold pre-assembled. They were enclosed in plastic or metal cases similar in appearance to typewriter or hi-fi equipment enclosures, which were more familiar and attractive to consumers than the industrial metal card-cage enclosures used by the Altair and similar computers. The keyboard - a feature lacking on the Altair - was usually built into the same case as the motherboard. Ports for plug-in peripheral devices such as a video display, cassette tape recorders, joysticks, and (later) disk drives were either built-in or available on expansion cards. Although the Apple II series had internal expansion slots, most other home computer models' expansion arrangements were through externally-accessible 'expansion ports' that also served as a place to plug in cartridge-based games. Usually, the manufacturer would sell peripheral devices designed to be compatible with their computers as extra-cost accessories. Peripherals and software were not often interchangeable between different brands of home computer, or even between successive models of the same brand.
The rise of the home computer also led to a fundamental shift during the early 1980s in where and how computers were purchased. Traditionally, microcomputers were obtained by mail order or were purchased in person at general electronics retailers like RadioShack. Silicon Valley, in the vanguard of the personal computer revolution, was the first place to see the appearance of new retail stores dedicated to selling only computer hardware, computer software, or both, and also the first place where such stores began to specialize in particular platforms.[18]
Almost universally, home computers had a BASIC interpreter combined with a line editor in permanent read-only memory, which one could use to type in BASIC programs and execute them immediately, or save them to tape or disk. In direct mode, the BASIC interpreter was also used as the user interface, and given tasks such as loading, saving, managing, and running files.[20] One exception was the Jupiter Ace, which had a Forth interpreter instead of BASIC. A built-in programming language was seen as a requirement for any computer of the era, and was the main feature setting home computers apart from video game consoles.
Some game consoles offered "programming packs" consisting of a version of BASIC in a ROM cartridge. Atari's BASIC Programming for the Atari 2600 was one of these. For the ColecoVision console, Coleco even announced an expansion module which would convert it into a full-fledged computer system. The Magnavox Odyssey console had a built-in keyboard to support its C7420 Home Computer Module. Among third-generation consoles, Nintendo's Family Computer offered Family BASIC (sold only in Japan), which included a keyboard that could be connected to an external tape recorder to load and store programs.
Introduced in August 1981, the IBM Personal Computer would eventually supplant CP/M as the standard platform used in business. This was largely due to the IBM name and the system's 16 bit open architecture, which expanded maximum memory tenfold, and also encouraged production of third-party clones. In the late 1970s, the 6502-based Apple II series had carved out a niche for itself in business, thanks to the industry's first killer app, VisiCalc, released in 1979. However, the Apple II would quickly be displaced for office use by IBM PC compatibles running Lotus 1-2-3.[25] Apple Computer's 1980 Apple III was underwhelming, and although the 1984 release of the Apple Macintosh introduced the modern GUI to the market, it was not common until IBM-compatible computers adopted it.[26] Throughout the 1980s, businesses large and small adopted the PC platform, leading, by the end of the decade, to sub-US$1000 IBM PC XT-class white box machines, usually built in Asia and sold by US companies like PCs Limited.
From the introduction of the IBM Personal Computer (ubiquitously known as the PC) in 1981, the market for computers meant for the corporate, business, and government sectors came to be dominated by the new machine and its MS-DOS operating system. Even basic PCs cost thousands of dollars and were far out of reach for typical home computer users. However, in the following years, technological advances and improved manufacturing capabilities (mainly greater use of robotics and relocation of production plants to lower-wage locations in Asia) permitted several computer companies to offer lower-cost, PC-style machines that would become competitive with many 8-bit home-market pioneers like Radio Shack, Commodore, Atari, Texas Instruments, and Sinclair. PCs could never become as affordable as these because the same price-reducing measures were available to all computer makers. Furthermore, software and peripherals for PC-style computers tended to cost more than those for 8-bit computers because of the anchoring effect caused by the pricey IBM PC. As well, PCs were inherently more expensive since they could not use the home TV set as a video display. Nonetheless, the overall reduction in manufacturing costs narrowed the price difference between old 8-bit technology and new PCs. Despite their higher absolute prices, PCs were perceived by many to be better values for their utility as superior productivity tools and their access to industry-standard software. Another advantage was the 8088/8086's wide, 20-bit address bus. The PC could access more than 64 kilobytes of memory relatively inexpensively (8-bit CPUs, which generally had multiplexed 16-bit address buses, required complicated, tricky memory management techniques like bank-switching). Similarly, the default PC floppy was double-sided, with about twice the storage capacity of floppy disks used by 8-bit home computers. PC drives tended to cost less because they were most often built-in, requiring no external case, controller, or power supply. The faster clock rates and wider buses available to later Intel CPUs compensated somewhat for the custom graphics and sound chips of the Commodores and Ataris. In time, the growing popularity of home PCs spurred many software publishers to offer gaming and children's software titles.[42]
Tandy Corporation capitalized on IBM's blunder with its PCjr-compatible Tandy 1000 in November. Like the PCjr, it was pitched as a home, education, and small-business computer, featuring joystick ports, better sound and graphics (same as the PCjr but with enhancements), combined with near-PC/DOS compatibility (unlike Tandy's earlier Tandy 2000). The improved Tandy 1000 video hardware became a standard of its own, known as Tandy Graphics Adapter or TGA. Later, Tandy produced Tandy 1000 variants in form factors and price-points even more suited to the home computer market, comprised particularly by the Tandy 1000 EX[43] and HX[44] models (later supplanted by the 1000 RL[45][46]), which came in cases resembling the original Apple IIs (CPU, keyboard, expansion slots, and power supply in a slimline cabinet) but also included floppy disk drives. The proprietary Deskmate productivity suite came bundled with the Tandy 1000s. Deskmate was suited to use by computer novices with its point-and-click (though not graphical) user interface. From the launch of the Tandy 1000 series, their manufacture were price-competitive because of Tandy's use of high-density ASIC chip technology, which allowed their engineers to integrate many hardware features into the motherboard (obviating the need for circuit cards in expansion slots as with other brands of PC). Tandy never transferred its manufacturing operation to Asia; all Tandy desktop computers were built in the USA (this was not true of the laptop and pocket computers, nor peripherals).
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