Microsoft IntelliType is the brand driver for Microsoft's series of computer keyboards. Microsoft releases versions for both Windows and Mac OS X, it has been succeeded by Microsoft Mouse and Keyboard Center, which combines IntelliType with IntelliPoint. IntelliType supports all known Microsoft keyboards. However, advanced features may only be available on certain models. Note: Version 8.0 and above dropped PS/2 support for the following list. As adapters can't assist, Microsoft keeps version 7.1 as an offered download for users who still own keyboards with PS/2 connectors. If the keyboard has multimedia buttons, the user can define them to run any action. On-screen indication of NumLock/CapsLock toggling with some keyboards. On-screen indication of volume level. While the user could always define special keys, it was only possible since version 6.3 to define them not just globally but per application. Version 6.2 forced the user to check for updates by installing and launching the file "dpupdchk.exe" in the background.
It must stay in the background for the control panel's settings to launch. Version 6.3 fixed this behavior by only making it an opt-in option during the installation. Version 7.0 and in Windows 7 64-bit has been proven to disable the media keys for third-party media players such as iTunes and Media Jukebox when they are not the primary window of focus. Some workaround exists: This behavior continues to be an issue as of Version 8. Microsoft Mouse and Keyboard Center IntelliPoint — Microsoft mouse driver. Microsoft IntelliType Hacks
AltGr is a modifier key found on some computer keyboards and is used to type characters that are unusual for the locale of the keyboard layout, such as currency symbols and accented letters. On a typical, IBM-compatible PC keyboard, the AltGr key, when present, takes the place of the right-hand Alt key. In macOS, the Option key has functions similar to the AltGr key. AltGr is used to the Shift key: it is held down when another key is struck in order to obtain a character other than the one that the latter produces. AltGr and Shift can sometimes be combined to obtain yet another character. For example, on the US-International keyboard layout, the C key can be used to insert four different characters: C → c ⇧ Shift+C → C AltGr+C → © AltGr+⇧ Shift+C → ¢ The meaning of the key's abbreviation is not explicitly given in many IBM PC compatible technical reference manuals. However, IBM states that AltGr is an abbreviation for alternate graphic, Sun keyboards label the key as Alt Graph. AltGr was introduced as a means to produce box-drawing characters known as pseudographics, in text user interfaces.
These characters are, much less useful in graphical user interfaces, rather than alternate graphic the key is today used to produce alternate graphemes. US PC keyboards did not have an AltGr key because, relevant to only non-US markets; the right Alt key is an equivalent of the AltGr key because both the right Alt key and the AltGr key share the same scancode and are indistinguishable by software. However, on some keyboards it may not be the case, i.e. the keyboard has two Alt keys, each of which acts as the left Alt key. On compact keyboards like those of netbooks, the right Alt key may be missing altogether. To allow the specific functionality of AltGr when typing non-English text on such keyboards, Windows allows it to be emulated by pressing the Alt key together with the Control key: Ctrl+Alt ≈ AltGrTherefore, it is recommended that this combination not be used as a modifier in Windows keyboard shortcuts as, depending on the keyboard layout and configuration, someone trying to type a special character with it may accidentally trigger the shortcut, or the keypresses for the shortcut may be inadvertently interpreted as the user trying to input a special character.
In the US-International keyboard layout, the AltGr key can be used to enter the following characters: ¡ ² ³ ¤ € ¼ ½ ¾ ‘ ’ ¥ × ä å é ® þ ü ú í ó ö « » á ß ð ø ¶ ´ ¬ æ © ñ µ ç ¿ and, in combination with the Shift key: ¹ £ ÷ Ä Å É Þ Ü Ú Í Ó Ö Á § Ð Ø ° ¨ ¦ Æ ¢ Ñ Ç Note that many of these symbols can be entered using dead keys. For comparison, the US-International keyboard layout follows. Note that the "`/~" key has been omitted. 1 2 3 4 5 6 7 8 9 0 - = q w e r t y u i o p a s d f g h j k l. Located on the "4/$" key. \ the Backslash symbol. Located on the "#/~" key. Either |, the vertical bar or ¦, the broken vertical bar. Located on the "`/¬" key, to the immediate left of "1"; the other bar symbol is the shift-keyed symbol on the "\" key to the left of the Z key. The two latter symbols interchange places in UK keyboards according to the operating system in use. In OS/2, the "UK keyboard layout" requires AltGr for the vertical bar and the broken vertical bar is a shifted key—which matches the actual symbols that are printed on most UK keyboards.
Using the AltGr key on Linux produces many foreign characters and international symbols, e.g. ¹²³€½@łe¶ŧ←↓→øþæßðđŋħjĸł«»¢“”nµΩŁE®Ŧ¥↑ıØÞÆ§ÐªŊĦJ&Ł<>©‘’Nº×÷· Using the AltGr key on UK and Irish keyboards in some versions of Windows in combination with vowel characters produces acute accents known as "fadas" in the Irish language over the vowels. The UK-Extended keyboard available in versions of Microsoft Windows from XP with SP2, Linux allows many characters with diacritical marks, including accents, to be generated by using the AltGr key in combination with others. Details are to be found at QWERTY § United Kingdom Layout. On South Slavic Latin keyboards, the following letters and special characters are created using AltGr: On Belgian keyboards, AltGr enables the user to type the following characters; those shown in bold are printed on the keys, common to all systems. For travellers who want to use hotel PCs or cybercafés in Belgium, it is important to know that @ in email addresses is generated by a combination of AltGr + é.
Digits row AltGr+² → ¬ AltGr+1 → | and ¡ (inverted exclamation mark
The Commodore 64 known as the C64 or the CBM 64, is an 8-bit home computer introduced in January 1982 by Commodore International. It has been listed in the Guinness World Records as the highest-selling single computer model of all time, with independent estimates placing the number sold between 10 and 17 million units. Volume production started in early 1982, marketing in August for US$595. Preceded by the Commodore VIC-20 and Commodore PET, the C64 took its name from its 64 kilobytes of RAM. With support for multicolor sprites and a custom chip for waveform generation, the C64 could create superior visuals and audio compared to systems without such custom hardware; the C64 dominated the low-end computer market for most of the 1980s. For a substantial period, the C64 had between 30% and 40% share of the US market and two million units sold per year, outselling IBM PC compatibles, Apple computers, the Atari 8-bit family of computers. Sam Tramiel, a Atari president and the son of Commodore's founder, said in a 1989 interview, "When I was at Commodore we were building 400,000 C64s a month for a couple of years."
In the UK market, the C64 faced competition from the BBC Micro and the ZX Spectrum, but the C64 was still one of the two most popular computers in the UK. Part of the Commodore 64's success was its sale in regular retail stores instead of only electronics or computer hobbyist specialty stores. Commodore produced many of its parts in-house to control costs, including custom integrated circuit chips from MOS Technology, it has been compared to the Ford Model T automobile for its role in bringing a new technology to middle-class households via creative and affordable mass-production. 10,000 commercial software titles have been made for the Commodore 64 including development tools, office productivity applications, video games. C64 emulators allow anyone with a modern computer, or a compatible video game console, to run these programs today; the C64 is credited with popularizing the computer demoscene and is still used today by some computer hobbyists. In 2011, 17 years after it was taken off the market, research showed that brand recognition for the model was still at 87%.
In January 1981, MOS Technology, Inc. Commodore's integrated circuit design subsidiary, initiated a project to design the graphic and audio chips for a next generation video game console. Design work for the chips, named MOS Technology VIC-II and MOS Technology SID, was completed in November 1981. Commodore began a game console project that would use the new chips—called the Ultimax or the Commodore MAX Machine, engineered by Yash Terakura from Commodore Japan; this project was cancelled after just a few machines were manufactured for the Japanese market. At the same time, Robert "Bob" Russell and Robert "Bob" Yannes were critical of the current product line-up at Commodore, a continuation of the Commodore PET line aimed at business users. With the support of Al Charpentier and Charles Winterble, they proposed to Commodore CEO Jack Tramiel a true low-cost sequel to the VIC-20. Tramiel dictated. Although 64-Kbit dynamic random-access memory chips cost over US$100 at the time, he knew that DRAM prices were falling, would drop to an acceptable level before full production was reached.
The team was able to design the computer because, unlike most other home-computer companies, Commodore had its own semiconductor fab to produce test chips. The chips were complete by November, by which time Charpentier and Tramiel had decided to proceed with the new computer; the product was code named the VIC-40 as the successor to the popular VIC-20. The team that constructed it consisted of Yash Terakura, Shiraz Shivji, Bob Russell, Bob Yannes and David A. Ziembicki; the design and some sample software were finished in time for the show, after the team had worked tirelessly over both Thanksgiving and Christmas weekends. The machine used the same case, same-sized motherboard, same Commodore BASIC 2.0 in ROM as the VIC-20. BASIC served as the user interface shell and was available on startup at the READY prompt; when the product was to be presented, the VIC-40 product was renamed C64. The C64 made an impressive debut at the January 1982 Consumer Electronics Show, as recalled by Production Engineer David A. Ziembicki: "All we saw at our booth were Atari people with their mouths dropping open, saying,'How can you do that for $595?'"
The answer was vertical integration. Commodore had a reputation for announcing products that never appeared, so sought to ship the C64. Production began in spring 1982 and volume shipments began in August; the C64 faced a wide range of competing home computers, but with a lower price and more flexible hardware, it outsold many of its competitors. In the United States the greatest competitors were the Atari 8-bit 400, the Atari 800, the Apple II; the Atari 400 and 800 had been designed to accommodate stringent FCC emissions requirements and so were expensive to
The Command key historically known as the Apple key, clover key, open-Apple key, splat key, pretzel key, or propeller key, is a modifier key present on Apple keyboards. The Command key's purpose is to allow the user to enter keyboard commands in applications and in the system. An "extended" Macintosh keyboard—the most common type—has two command keys, one on each side of the space bar; the "⌘" symbol was chosen by Susan Kare after Steve Jobs decided that the use of the Apple logo in the menu system would be an over-use of the logo. Apple's adaptation of the symbol—encoded in Unicode at U+2318 ⌘ —was derived in part from its use in Nordic countries as an indicator of cultural locations and places of interest; the symbol is known by various other names, including "Saint John's Arms" and "Bowen knot". Apple's computers up through the 1979 Apple II Plus did not have a command key; the first model on which it appeared was the 1980 Apple III, where there are two monochrome Apple keys, both to the left of the space bar on the lowest row of the keyboard.
Two other early Apple computers, the 1982 Apple IIe and the 1984 Apple IIc had two such keys, one to the left and one to the right of the space bar. This allowed for flexible combinations of a modifier key and base key with just a few extra wires and no ROM changes, since the Apple II could only register one key press at a time. In all these cases, the left Apple key had an outlined "open" Apple logo, the one on the right had an opaque, "closed" or "solid" Apple logo key; the Apple Lisa had only the closed Apple logo. When the Macintosh was introduced in 1984, the keyboard had a single command key with a Looped square symbol, because Steve Jobs said that showing the Apple logo throughout the menus as a keyboard shortcut was "taking in vain". Thus, the ⌘ symbol appears in the Macintosh menus as the primary modifier key symbol; the original Macintosh had an Option key, used for entering extended characters. In 1986, the Apple IIGS was introduced. Like the newer Macintosh computers to come, such as the Macintosh SE, it used the Apple Desktop Bus for its keyboard and mouse.
However, it was still an Apple II. Apple changed the keys on the IIGS's keyboard to Command and Option, as on Mac keyboards, but added an open-Apple to the Command key, for consistency with applications for previous Apple II generations; because any ADB keyboard could be used with the IIGS, all of Apple's ADB keyboards—even those intended for the Mac—also required the open-Apple, it stuck for more than twenty years, causing confusion long after the Apple II series went out of production. The Apple symbol was removed in the keyboard's 2007 redesign, making room for the key's name to appear—the word "command" is now printed on the key. On the keyboard of the NeXT Computer that key was marked Command in green; the menus were not marked with a symbol denoting the command key. Besides being used as a modifier key for keyboard shortcuts it was used to alter the function of some keys. Command + ⇧ Shift toggles alpha lock, Command + Return sends Command + Volume-down toggles Mute; the functions were printed in green on the front side of the modified keys.
This was done on the Z, X, C and V keys. Command-Alternate-* triggers a non-catchable hardware reset thereby hard rebooting the computer. On the NeXT ADB keyboard, the Command keys were replaced by keys labeled Help and the Command key morphed into a wide Command bar in front of the space bar; the purpose of the Command key is to allow the user to enter keyboard commands in applications and in the system. The Macintosh Human Interface Guidelines have always recommended that developers use the Command key for this purpose. A small set of keyboard commands are standard across nearly all applications, many other commands are standardized. If an application needs more shortcuts than can be obtained with the twenty-six letters of the Latin alphabet, double modifiers such as Command+Option are used. One advantage of this scheme, as contrasted with the Microsoft Windows mixed use of the Control and Alt keys, is that the Control key is available for its original purpose: entering control characters in terminal applications.
The Macintosh keyboard's other unusual modifier key, the Option key, serves as a modifier both for entering keyboard shortcuts and for typing text—it is used to enter foreign characters, typographical symbols, other special characters. The ⌘ symbol came into the Macintosh project at a late stage; the development team went for their old Apple key, but Steve Jobs found it frustrating when "apples" filled up the Mac's menus next to the key commands, because he felt that this was an over-use of the company logo. He opted for a different key symbol. With only a few days left before deadline, the team's bitmap artist Susan Kare started researching for the Apple logo's successor, she was browsing through a symbol dictionary when she came across the
A function key is a key on a computer or terminal keyboard which can be programmed so as to cause an operating system command interpreter or application program to perform certain actions, a form of soft key. On some keyboards/computers, function keys may have default actions, accessible on power-on. Function keys on a terminal may either generate short fixed sequences of characters beginning with the escape character, or the characters they generate may be configured by sending special character sequences to the terminal. On a standard computer keyboard, the function keys may generate a fixed, single byte code, outside the normal ASCII range, translated into some other configurable sequence by the keyboard device driver or interpreted directly by the application program. Function keys may have default actions printed on/besides them, or they may have the more common "F-number" designations; the Singer/Friden 2201 Flexowriter Programatic, introduced in 1965, had a cluster of 13 function keys, labeled F1 to F13 to the right of the main keyboard.
Although the Flexowriter could be used as a computer terminal, this electromechanical typewriter was intended as a stand-alone word processing system. The interpretation of the function keys was determined by the programming of a plugboard inside the back of the machine. Soft keys date to avionics multi-function displays of military planes of the late 1960s/early 1970s, such as the Mark II avionics of the F-111D. In computing use, they were found on the HP 9810A calculator and models of the HP 9800 series, which featured 10 programmable keys in 5×2 block at the top left of the keyboard, with paper labels; the HP 9830A was an early desktop computer, one of the earliest computing uses. HP continued its use of function keys in the HP 2640, which used screen-labeled function keys, placing the keys close to the screen, where labels could be displayed for their function. NEC's PC-8001, introduced in 1979, featured five function keys at the top of the keyboard, along with a numeric keypad on the right-hand side of the keyboard.
Their modern use may have been popularized by IBM keyboards: first the IBM 3270 terminals the IBM PC. IBM use of function keys dates to the IBM 3270 line of terminals the IBM 3277 with 78-key typewriter keyboard or operator console keyboard version, which both featured 12 programmed function keys in a 3×4 matrix at the right of the keyboard. Models replaced this with a numeric keypad, moved the function keys to 24 keys at the top of the keyboard; the original IBM PC keyboard had 10 function keys in a 2×5 matrix at the left of the keyboard. Since the introduction of the Apple Extended Keyboard with the Macintosh II, keyboards with function keys have been available, though they did not become standard until the mid-1990s, they have not traditionally been a major part of the Mac user interface and are only used on cross-platform programs. According to the Macintosh Human Interface Guidelines, they are reserved for customization by the user. Current Mac keyboards include specialized function keys for controlling sound volume.
The most recent Mac keyboards include 19 function keys, but keys F1–F4 and F7–F12 by default control features such as volume, media control, Exposé. Former keyboards and Apple Keyboard with numeric keypad has the F1–F19 keys. Apple Macintosh notebooks: Function keys were not standard on Apple notebook hardware until the introduction of the PowerBook 5300 and the PowerBook 190. For the most part, Mac laptops have keys F1 through F12, with pre-defined actions for some, including controlling sound volume and screen brightness. Apricot PC/Xi: six unlabelled keys, each with an LED beside it which illuminates when the key can be used. Atari 8-bit family: four dedicated keys at the right hand side or on the top of the keyboard. Atari 1200XL had four additional keys labeled F1 through F4 with pre-defined actions related to cursor movement. Atari ST: ten parallelogram-shaped keys in a horizontal row across the top of the keyboard, inset into the keyboard frame instead of popping up like normal keys. BBC Micro: red/orange keys F0 to F9 in a horizontal row above the number keys on top of the computer/keyboard.
The break and copy keys could function as F10–F15. The case included a transparent plastic strip above them to hold a function key reference card. Coleco Adam: six dark brown keys in a horizontal row above the number keys, labeled with Roman numerals I–VI. Commodore VIC-20 and C64: F1/F2 to F7/F8 in a vertical row of four keys ascending downwards on the computer/keyboard's right hand side, odd-numbered functions accessed unshifted, even-numbered shifted. Commodore 128: same as VIC-20/C64, but with function keys placed in a horizontal row above the numeric keypad right of the main QWERTY-keyboard. Commodore Amiga: ten keys ar
The Apple Keyboard is a keyboard designed by Apple Inc. first for the Apple line the Macintosh line of computers. Dozens of models have been released over time, including the Apple Extended Keyboard. Apple offers only three keyboards via Bluetooth: Magic Keyboard, Magic Keyboard with Numeric Keypad; the space gray model is included with the iMac Pro. Both share a similar look and feel, based on a thin aluminum chassis and laptop-style low-profile keys, sitting much closer to the tabletop than traditional keyboard designs. To serve the functionality of the Macintosh operating systems, the Apple Keyboard's layout differs somewhat from that of the ubiquitous IBM PC keyboard in its modifier and special keys; some of these keys have unique symbols defined in the Unicode block Miscellaneous Technical. Features different from other keyboards include: The Command key, used in most Mac keyboard shortcuts; the key functions as a Meta key in Unix-like environments, is equivalent to the Windows key in Windows environments, although in common applications it performs the same function as the Windows Control key.
Compared to their equivalents on the standard IBM PC keyboard layout the Command key and the Option key are located in reverse order. The "open" and separate "closed" Apple logo keys on the Apple II series, served functions similar to that of the Command key; the open-Apple key was combined with the Command key on Apple Desktop Bus keyboards where it remained after the Apple II line was discontinued. The Option key, for entering diacritics and other special characters. Like the Shift and Control keys, the Option key serves as a modifier for the Command key shortcuts, as well as being used to type many special characters, it serves the function of the solid-Apple key in Apple II applications. It functions as the Alt key in Windows environments. Compared to their equivalents on the standard IBM PC keyboard layout the Command key and the Option key are located in reverse order. Full-sized desktop keyboards with a dedicated numpad have function keys that can range up to F15, F16, or F19. F17-F19 keys were introduced with the aluminium USB keyboard.
Compact keyboards such as the bluetooth wireless aluminium keyboard and the built-in keyboards on all Intel-based Macintosh notebooks range from F1-F12 only, just like IBM PC keyboards. A Clear key, instead of a Num Lock key, on models with full numeric keypads, as these are dedicated to numeric input and not used for cursor control. In Unicode, the Clear key is represented by U+2327 ⌧ X IN A RECTANGLE BOX, defined as "clear key". An "equals" key added to the numeric keypad. A Help key, instead of an Insert key, or on the most recent aluminum keyboards, a fn key, which toggles the function of the function keys between their default functions and special functions. Notebook computers include additional assignments shared with function keys – reduce and increase brightness, volume up, volume down and eject. Apple, since the release of the Pro Keyboard, provides these last four keys on desktop keyboards above the numeric keypad where status indicator lights are on many IBM PC keyboards. On the newest aluminum keyboard, these functions are accessed with the function keys, just like on the Apple laptops.
On Apple Desktop Bus keyboards, a power key, used to turn on computers. On keyboards with function keys, it was placed either on the left or right edge of the same keyboard row as the function keys; the power key was replaced with a more conventional power button on early USB keyboards, thanks to a proprietary pin wired to the Macintosh's power supply in Apple's early USB implementations, subsequently eliminated on the Pro Keyboard along with the special power supply pin. Most of its functions were transferred to the eject key in such keyboards; the Apple UK keyboard layout" keys in their US locations. These are reversed on non-Apple UK keyboards; the Macintosh keyboards are somewhat reminiscent of the keyboards used for the Apple II. Apple's first offering, the Apple I, was sold as a naked PCB without a keyboard, although some resellers and users fitted their own cases with built-in keyboards and Apple cooperated with at least one such reseller. Starting in 1977, the first real Apple keyboards were built into the cases of the Apple II series and the Apple III series systems.
These first keyboards had chocolate brown keycaps with white legends. The Apple II and Apple II+ keyboard had 52 keys, the Apple III keyboard, which included a numeric pad and some other additional keys, had 74. In 1983, the new Apple IIe and Apple III+ models introduced a beige keyboard with smaller black legends. In the same year, Apple introduced its first separate keyboard with the Lisa, it connected via a unique TRS port. The Macintosh updated the look somewhat and separated the numerical keypad from the alphanumeric unit, all of which connected by telephone-style modular cables. By 1986, the Macintosh Plus re-integrated the numerical keypad and became the standard for all successive keyboards. However, it marked the last of the beige Apple-II-era designs which were usurped by the newer Snow White design language. From the end of 1986 until mid-1998, all
The ZX Spectrum is an 8-bit personal home computer released in the United Kingdom in 1982 by Sinclair Research. Referred to during development as the ZX81 Colour and ZX82, it was launched as the ZX Spectrum by Sinclair to highlight the machine's colour display, compared with the black and white of its predecessor, the ZX81; the Spectrum was released as eight different models, ranging from the entry level with 16 KB RAM released in 1982 to the ZX Spectrum +3 with 128 KB RAM and built in floppy disk drive in 1987. The Spectrum was among the first mainstream-audience home computers in the UK, similar in significance to the Commodore 64 in the US; the introduction of the ZX Spectrum led to a boom in companies producing software and hardware for the machine, the effects of which are still seen. Some credit it as the machine. Licensing deals and clones followed, earned Clive Sinclair a knighthood for "services to British industry"; the Commodore 64, Dragon 32, Oric-1, Oric Atmos, BBC Micro and the Amstrad CPC range were rivals to the Spectrum in the UK market during the early 1980s.
While the machine was discontinued in 1992, new software titles continue to be released – over 40 so far in 2018. The Spectrum is based on a Zilog Z80 A CPU running at 3.5 MHz. The original model has 16 KB of ROM and either 16 KB or 48 KB of RAM. Hardware design was by Richard Altwasser of Sinclair Research, the outward appearance was designed by Sinclair's industrial designer Rick Dickinson. Video output is through an RF modulator and was designed for use with contemporary television sets, for a simple colour graphic display. Text can be displayed using 32 columns × 24 rows of characters from the ZX Spectrum character set or from a set provided within an application, from a palette of 15 shades: seven colours at two levels of brightness each, plus black; the image resolution is 256×192 with the same colour limitations. To conserve memory, colour is stored separate from the pixel bitmap in a low resolution, 32×24 grid overlay, corresponding to the character cells. In practice, this means that all pixels of an 8x8 character block share one foreground colour and one background colour.
Altwasser received a patent for this design. An "attribute" consists of a foreground and a background colour, a brightness level and a flashing "flag" which, when set, causes the two colours to swap at regular intervals; this scheme leads to what was dubbed colour clash or attribute clash, where a desired colour of a specific pixel could not be selected. This became a distinctive feature of the Spectrum, meaning programs games, had to be designed around this limitation. Other machines available around the same time, for example the Amstrad CPC or the Commodore 64, did not suffer from this limitation; the Commodore 64 used colour attributes in a similar way, but a special multicolour mode, hardware sprites and hardware scrolling were used to avoid attribute clash. Sound output is through a beeper on the machine itself, capable of producing one channel with 10 octaves. Software was available that could play two channel sound; the machine includes an expansion bus edge connector and 3.5 mm audio in/out ports for the connection of a cassette recorder for loading and saving programs and data.
The "ear" port has a higher output than the "mic" and is recommended for headphones, with "mic" for attaching to other audio devices as line in. It was manufactured in Scotland, in the now closed Timex factory; the machine's Sinclair BASIC interpreter is stored in ROM and was written by Steve Vickers on contract from Nine Tiles Ltd. The Spectrum's chiclet keyboard is marked with BASIC keywords. For example, pressing "G" when in programming mode would insert the BASIC command GO TO; the BASIC interpreter was developed from that used on the ZX81 and a ZX81 BASIC program can be typed into a Spectrum unmodified, but Spectrum BASIC included many extra features making it easier to use. The ZX Spectrum character set was expanded from that of the ZX81, which did not feature lower-case letters. Spectrum BASIC included extra keywords for the more advanced display and sound, supported multi-statement lines; the cassette interface was much more advanced and loading around five times faster than the ZX81, unlike the ZX81, the Spectrum could maintain the TV display during tape storage and retrieval operations.
As well as being able to save programs, the Spectrum could save the contents of arrays, the contents of the screen memory, the contents of any defined range of memory addresses. Rick Dickinson came up with a number of designs for the "ZX82" project before the final ZX Spectrum design. A number of the keyboard legends changed during the design phase including ARC becoming CIRCLE, FORE becoming INK and BACK becoming PAPER; the Spectrum reused a number of design elements of the ZX81: The ROM code for things such as floating point calculations and expression parsing were similar. The simple keyboard decoding and cassette interfaces were nearly identical; the central ULA integrated circuit was somewhat similar although it implemented the major enhancement over the ZX81: A hardware based television raster generator that indirectly gave the new machine four times as much processing power as the ZX81 due to the Z80 now being released from this video generation task. A bug in the ULA as designed