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85-596: Applesoft BASIC is a dialect of Microsoft BASIC , developed by Marc McDonald and Ric Weiland , supplied with Apple II computers. It supersedes Integer BASIC and is the BASIC in ROM in all Apple II series computers after the original Apple II model. It is also referred to as FP BASIC (from floating point ) because of the Apple DOS command FP used to invoke it, instead of INT for Integer BASIC. Applesoft BASIC

170-596: A SYSTEM keyword. A modified version published later by OS provider Logical Systems, in the LS-DOS Version 6.3 update, added single-letter access to BASIC control functions (like LIST and EDIT ) and direct access to LS-DOS supervisor calls. The program edit environment was still line-oriented. The facility available in Level II to sort arrays ( CMD"O" ) was not available; programmers and users had to devise their own workarounds. The first implementation as

255-715: A deterministic random bit generator ( DRBG ), is an algorithm for generating a sequence of numbers whose properties approximate the properties of sequences of random numbers . The PRNG-generated sequence is not truly random , because it is completely determined by an initial value, called the PRNG's seed (which may include truly random values). Although sequences that are closer to truly random can be generated using hardware random number generators , pseudorandom number generators are important in practice for their speed in number generation and their reproducibility. PRNGs are central in applications such as simulations (e.g. for

340-517: A pseudorandom fractional number between 0 and 1. RND(0) returns the most recently generated random number. RND with a negative number will jump to a point in the sequence determined by the particular negative number used. RND with any positive value generates the next number in the sequence, not dependent on the actual value given. Like other implementations of Microsoft BASIC, Applesoft discards spaces (outside of strings and comments) on program lines. LIST adds spaces when displaying code for

425-425: A "double-high resolution" mode became available on machines with 128k of memory. This mode essentially duplicates the resolution of the original high resolution mode, but including all 16 colors of the low resolution palette. Applesoft does not provide direct support for this mode. Apple IIGS -specific modes are likewise not supported. Applesoft BASIC can be extended by two means: the ampersand ( & ) command and

510-486: A BASIC compatible with Applesoft to VTech for its Laser 128 clone . This article includes text from Everything2 , licensed under GFDL. Microsoft BASIC During the home computer craze of the late-1970s and early-1980s, BASIC was ported to and supplied with many home computer designs. Slight variations to add support for machine-specific functions, especially graphics, led to a profusion of related designs like Commodore BASIC and Atari Microsoft BASIC . As

595-475: A BASIC program listing to the printer, the user types PR#x:LIST . Using PR# on a slot with a disk drive (usually in slot 6) causes Applesoft to boot the disk drive. Using PR# on a slot with an 80 column card (usually in slot 3) switches to 80 column text mode. As with Commodore BASIC, numeric variables are stored as 40-bit floating point; each variable requires five bytes of memory. The programmer may designate variables as integer by following them with

680-515: A CSPRNG. Some classes of CSPRNGs include the following: It has been shown to be likely that the NSA has inserted an asymmetric backdoor into the NIST -certified pseudorandom number generator Dual_EC_DRBG . Most PRNG algorithms produce sequences that are uniformly distributed by any of several tests. It is an open question, and one central to the theory and practice of cryptography , whether there

765-534: A Microsoft copyright notice. To maintain consistency with Integer BASIC, the "Ok" prompt from Microsoft's code was replaced by a ] character. Applesoft 1.x also prompted the user upon loading if they wished to disable the REM statement and the LET keyword in assignment statements in exchange for lores graphics commands. The USR() function is also defined differently, serving as a stand-in for the absent CALL command. Its argument

850-621: A ROM-based MSX BASIC for use in MSX home computers , which used a Z80 processor. This version supported the graphics and sound systems of the MSX computers; some variants also had support for disk drives. No variety of Microsoft BASIC ( BASICA , GW-BASIC , QuickBasic , QBasic ) is currently distributed with Microsoft Windows or DOS . However, versions that will still run on modern machines can be downloaded from various Internet sites or be found on old DOS disks. The latest incarnation of Microsoft BASIC

935-569: A crash. The built-in pseudorandom number generator function RND is capable of producing a predictable series of outputs due to the manner in which the generator is seeded when first powering on. This behavior is contrary to how Apple's documentation describes the function. Wozniak originally referred to his Integer BASIC as "Game BASIC" (having written it so he could implement a Breakout clone for his new computer). Few action games were written in Applesoft BASIC, in large part because

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1020-470: A few months this was replaced by a port of BASIC-80 which incorporated some of Level I BASIC's command set, particularly the commands for setting graphics characters. Level II BASIC contained some of the features of Extended BASIC, although due to the need to include Level I commands such as SET and PSET , other features such as descriptive error messages still had to be left out; these were subsequently added into TRS-80 Disk BASIC. The TRS-80 Model 4 had

1105-670: A function f : N 1 → R {\displaystyle f:\mathbb {N} _{1}\rightarrow \mathbb {R} } (where N 1 = { 1 , 2 , 3 , … } {\displaystyle \mathbb {N} _{1}=\left\{1,2,3,\dots \right\}} is the set of positive integers) a pseudo-random number generator for P {\displaystyle P} given F {\displaystyle {\mathfrak {F}}} taking values in A {\displaystyle A} if and only if : ( # S {\displaystyle \#S} denotes

1190-658: A long period (see middle-square method ). Numbers selected from a non-uniform probability distribution can be generated using a uniform distribution PRNG and a function that relates the two distributions. First, one needs the cumulative distribution function F ( b ) {\displaystyle F(b)} of the target distribution f ( b ) {\displaystyle f(b)} : Note that 0 = F ( − ∞ ) ≤ F ( b ) ≤ F ( ∞ ) = 1 {\displaystyle 0=F(-\infty )\leq F(b)\leq F(\infty )=1} . Using

1275-467: A newer disk-based BASIC that utilized the BASIC-80 5.x core, which included support for 40-character variable names. Thus the ability to crunch program lines (without spaces between keywords and arguments) was no longer possible as it had been in Level II. It was no longer necessary to reserve string space. New features included user defined functions ( DEF FN ) and access to TRSDOS 6 system functions via

1360-423: A percent sign, in which case they use two bytes and are limited to a range of -32768 to 32767; however BASIC internally converts them back to floating point when performing calculations, while each percent sign also takes an additional byte of program code, so in practice this feature is only useful for reducing the memory usage of large array variables, as it offers no performance benefit. The RND function generates

1445-579: A random number c from a uniform distribution as the probability density to "pass by", we get so that is a number randomly selected from distribution f ( b ) {\displaystyle f(b)} . This is based on the inverse transform sampling . For example, the inverse of cumulative Gaussian distribution erf − 1 ⁡ ( x ) {\displaystyle \operatorname {erf} ^{-1}(x)} with an ideal uniform PRNG with range (0, 1) as input x {\displaystyle x} would produce

1530-593: A random sequence. In other words, while a PRNG is only required to pass certain statistical tests, a CSPRNG must pass all statistical tests that are restricted to polynomial time in the size of the seed. Though a proof of this property is beyond the current state of the art of computational complexity theory , strong evidence may be provided by reducing to the CSPRNG from a problem that is assumed to be hard , such as integer factorization . In general, years of review may be required before an algorithm can be certified as

1615-547: A self-written Intel 8080 emulator running on a PDP-10 minicomputer . The MS dialect is patterned on Digital Equipment Corporation 's BASIC-PLUS on the PDP-11 , which Gates had used in high school . The first versions supported integer math only, but Monte Davidoff convinced them that floating-point arithmetic was possible, and wrote a library which became the Microsoft Binary Format . Altair BASIC

1700-443: A shortcut for "PRINT", though spelling out the word is not only acceptable but canonical—Applesoft converted "?" in entered programs to the same token as "PRINT" (thus no memory is actually saved by using "?"), thus either appears as "PRINT" when a program is listed. The program above appears in a LIST command as: When Applesoft II BASIC was initially released in mid-1978, it came on cassette tape and could be loaded into memory via

1785-519: A shorthand for CALL , with an address that is predefined. By calling routines in the Applesoft ROM, it is possible for ampersand routines to parse values that follow the ampersand. Numerous third-party commercial packages were available to extend Applesoft using ampersand routines. A deficiency with error-trapping via ONERR means that the system stack is not reset if an error-handling routine does not invoke RESUME , potentially leading to

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1870-468: A simulation of the standard uniform distribution. An early computer-based PRNG, suggested by John von Neumann in 1946, is known as the middle-square method . The algorithm is as follows: take any number, square it, remove the middle digits of the resulting number as the "random number", then use that number as the seed for the next iteration. For example, squaring the number "1111" yields "1234321", which can be written as "01234321", an 8-digit number being

1955-433: A source listing for Microsoft 6502 BASIC which proved to be buggy and also required the addition of Integer BASIC commands. Since Apple had no 6502 assembler on hand, the development team was forced to send the source code over the phone lines to Call Computer, an outfit that offered compiler services. This was an extremely tedious, slow process and after Call Computer lost the source code due to an equipment malfunction, one of

2040-455: A standalone disk-based language system was for Seattle Computer Products S-100 bus 8086 CPU card in 1979. It was utilizing an 8-bit FAT file system. Microsoft also offered a version of Standalone BASIC-86 for SBC-86/12 for Intel's 8086 Single Board Computer platform in 1980. This is the version of BASIC used on the TI-99/4A home computer. Although very similar to Microsoft BASIC, it

2125-495: Is Visual Basic .NET , which incorporates some features from C++ and C# and can be used to develop Web forms, Windows forms, console applications and server-based applications. Most .NET code samples are presented in VB.NET as well as C#, and VB.NET continues to be favored by former Visual Basic programmers . In October 2008, Microsoft released Small Basic . The language has only 14 keywords. Small Basic Version 1.0 (12 June 2011)

2210-639: Is a pseudo-random number generator for P {\displaystyle P} , where F ∗ : ( 0 , 1 ) → R {\displaystyle F^{*}:\left(0,1\right)\rightarrow \mathbb {R} } is the percentile of P {\displaystyle P} , i.e. F ∗ ( x ) := inf { t ∈ R : x ≤ F ( t ) } {\displaystyle F^{*}(x):=\inf \left\{t\in \mathbb {R} :x\leq F(t)\right\}} . Intuitively, an arbitrary distribution can be simulated from

2295-422: Is a valid command but print and Print result in a syntax error. Applesoft lacks several commands and functions common to most of the non-6502 Microsoft BASIC interpreters, such as: Applesoft does not have commands for file or disk handling, other than to save and load programs via cassette tape. The Apple II disk operating system, known simply as DOS, augments the language to provide such abilities. Only

2380-492: Is an important factor in the cryptographic suitability of a PRNG, but not the only one. The German Federal Office for Information Security ( German : Bundesamt für Sicherheit in der Informationstechnik , BSI) has established four criteria for quality of deterministic random number generators. They are summarized here: For cryptographic applications, only generators meeting the K3 or K4 standards are acceptable. Given: We call

2465-412: Is any way to distinguish the output of a high-quality PRNG from a truly random sequence. In this setting, the distinguisher knows that either the known PRNG algorithm was used (but not the state with which it was initialized) or a truly random algorithm was used, and has to distinguish between the two. The security of most cryptographic algorithms and protocols using PRNGs is based on the assumption that it

2550-414: Is infeasible to distinguish use of a suitable PRNG from use of a truly random sequence. The simplest examples of this dependency are stream ciphers , which (most often) work by exclusive or -ing the plaintext of a message with the output of a PRNG, producing ciphertext . The design of cryptographically adequate PRNGs is extremely difficult because they must meet additional criteria. The size of its period

2635-462: Is not for passing a numerical value to the machine-language routine, but is instead the call-address of the routine itself; there is no "hook" to pre-define the address. All of several examples in the manual use the function only to access "system monitor ROM" routines, or short user-routines to manipulate the ROM routines. No mention is made of any code to calculate the value returned by the function itself;

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2720-589: Is required to have any confidence that a PRNG generates numbers that are sufficiently close to random to suit the intended use. John von Neumann cautioned about the misinterpretation of a PRNG as a truly random generator, joking that "Anyone who considers arithmetical methods of producing random digits is, of course, in a state of sin." In practice, the output from many common PRNGs exhibit artifacts that cause them to fail statistical pattern-detection tests. These include: Defects exhibited by flawed PRNGs range from unnoticeable (and unknown) to very obvious. An example

2805-520: Is sometimes required, as illustrated by the following warning in the International Encyclopedia of Statistical Science (2010). The list of widely used generators that should be discarded is much longer [than the list of good generators]. Do not trust blindly the software vendors. Check the default RNG of your favorite software and be ready to replace it if needed. This last recommendation has been made over and over again over

2890-547: Is the Mersenne Twister (discussed below), which was published in 1998. Other higher-quality PRNGs, both in terms of computational and statistical performance, were developed before and after this date; these can be identified in the List of pseudorandom number generators . In the second half of the 20th century, the standard class of algorithms used for PRNGs comprised linear congruential generators . The quality of LCGs

2975-548: The PRINT USING statement. As compensation for not having double precision variables, Microsoft included 40-bit floating point support instead of BASIC-80's 32-bit floating point and string allocation was dynamic (thus the user did not have to reserve string space like in BASIC-80). However, vendors could still request BASIC with 32-bit floating point for a slightly smaller memory footprint ; as one example, Disk BASIC for

3060-450: The USR() function. These are two features that call low-level machine-language routines stored in memory, which is useful for routines that need to be fast or require direct access to arbitrary functions or data in memory. The USR() function takes one argument, and can be programmed to derive and return a calculated function value to be used in a numerical expression. & is effectively

3145-622: The Apple II , he did not implement support for floating-point arithmetic because he was primarily interested in writing games, a task for which integers alone were sufficient. In 1976, Microsoft had developed Microsoft BASIC for the MOS Technology 6502 , but at the time there was no production computer that used it. Upon learning that Apple had a 6502 machine, Microsoft asked if the company were interested in licensing BASIC, but Steve Jobs replied that Apple already had one. The Apple II

3230-459: The Disk II drive and controller and with Apple DOS , Apple turned to Microsoft. Apple reportedly obtained an eight-year license for Applesoft BASIC from Microsoft for a flat fee of $ 31,000, renewing it in 1985 through an arrangement that gave Microsoft the rights and source code for Apple's Macintosh version of BASIC . Applesoft was designed to be backwards-compatible with Integer BASIC and uses

3315-595: The Epson HX-20 portable computer, which has two Hitachi 6301 CPUs, which are essentially a "souped up" 6801. Most of the core features in BASIC-68 and BASIC-69 were copied directly from BASIC-80. BASIC-69 was notably also licensed to Tandy, where it formed the nucleus of Color BASIC on the TRS-80 Color Computer . Not to be confused with BASIC09 , a very different BASIC created by Microware as

3400-501: The File Allocation Table (FAT) was a BASIC adaptation for an Intel 8080 -based NCR 7200 , 7520 , or 7530 data-entry terminal with 8-inch floppy disks in 1977/1978. Microsoft offered a BASIC compiler for BASIC-80 under CP/M, by 1980 or before. The compiler executable was named BASCOM or BASCOM32. The TRS-80 computer was offered initially with an adaption of Li-Chen Wang's Tiny BASIC ( Level I BASIC ); within

3485-472: The Monte Carlo method ), electronic games (e.g. for procedural generation ), and cryptography . Cryptographic applications require the output not to be predictable from earlier outputs, and more elaborate algorithms , which do not inherit the linearity of simpler PRNGs, are needed. Good statistical properties are a central requirement for the output of a PRNG. In general, careful mathematical analysis

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3570-615: The user interface of many home computers' rudimentary operating systems . By 1981, Microsoft BASIC was so popular that even companies that already had a BASIC licensed the language, such as IBM for its Personal Computer , and Atari , which sold both Atari Microsoft BASIC and its own Atari BASIC . IBM's Don Estridge said, "Microsoft BASIC had hundreds of thousands of users around the world. How are you going to argue with that?" Microsoft licensed similar versions to companies that competed with each other. After licensing IBM Advanced BASIC (BASICA) to IBM, for example, Microsoft licensed

3655-621: The 6502 during the summer of 1976; it was mostly a straight port of the 8K version of BASIC-80 and included the same prompts asking for memory size and if the user wanted floating point functions enabled or not (having them active used an extra 135 bytes of memory). The earliest machines to use 6502 BASIC were the Ohio Scientific Model 500 and KIM-1 in 1977. 6502 BASIC included certain features from Extended BASIC such as user-defined functions and descriptive error messages, but omitted other features like double precision variables and

3740-528: The ASCII string is converted whenever the line is executed. Since variable lookup is often faster than this conversion, it can be faster to store numeric constants used inside loops in variables before the loop is entered. Hello, World! in Applesoft BASIC can be entered as the following: Multiple commands can be included on the same line of code if separated by a colon ( : ). The ? can be used in Applesoft BASIC (and almost all versions of Microsoft BASIC) as

3825-515: The Apple II's low resolution and high resolution modes. There are commands to plot pixels and draw horizontal and vertical lines in low resolution. High resolution allows arbitrary lines and vector-based shape tables for drawing scaled and rotated objects. The only provision for mixing text and graphics is the four lines of text at the bottom of a graphic display. Beginning with the Apple IIe ,

3910-549: The Apple II's machine language monitor. When the enhanced Apple II+ replaced the original II in 1979, Applesoft was now included in ROM and automatically started on power-up if no bootable floppy disk was present. Conversely, Integer BASIC was now removed from ROM and turned into an executable file on the DOS 3.3 disk. The original Applesoft, stored in RAM as documented in its Reference Manual of November 1977, has smaller interpreter code than

3995-482: The Atari 8-bits used 32-bit floating point rather than 40-bit. Standard features of the 9K version of Microsoft 6502 BASIC included: 6502 BASIC lacked a standardized set of commands for disk and printer output; these were up to the vendor to add and varied widely with each implementation. Later implementations of 6502 Basic (1983–) had many vendor specific improvements; for example later versions of Commodore BASIC had

4080-472: The Boolean operators AND, OR and NOT perform bitwise operations on 16-bit integer values. If they are given values outside that range, an error results. The terms OUT and PLT (and the aforementioned IN) appear in the list of reserved words, but are not explained anywhere in the manual. Coleco claimed that its Adam home computer's SmartBASIC was source-code compatible with Applesoft. Microsoft licensed

4165-464: The ROM of the Apple II Plus and subsequent models, was released in 1978. It is this latter version, which has some syntax differences and support for the Apple II high-resolution graphics modes, that is usually synonymous with the term "Applesoft." A compiler for Applesoft BASIC, TASC (The Applesoft Compiler), was released by Microsoft in 1981. When Steve Wozniak wrote Integer BASIC for

4250-440: The ability to crunch program lines. The core command set and syntax are the same in all implementations of Microsoft BASIC and, generally speaking, a program can be run on any version if it does not use hardware-specific features or double precision numbers (not supported in some implementations). After the initial success of Altair BASIC, Microsoft BASIC became the basis for a lucrative software licensing business, being ported to

4335-449: The card is specified after the PR# or IN# within the statement. The computer locks-up if there is no card present in the slot. PR#0 restores output to the 40 column screen and IN#0 to the keyboard. The PR# statement can be used to redirect output to the printer (e.g. 10 PR# x: PRINT "Hello!" ) where x is the slot number containing the printer port card. To send

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4420-500: The command to invoke the low-resolution graphics mode, and results in a syntax error. The only sound support is the option to PRINT an ASCII bell character to sound the system alert beep , and a PEEK command to click the speaker. The language is not fast enough to produce more than a baritone buzz from repeated clicks. Programs can, however, store a machine-language routine to be called to generate electronic musical tones spanning several octaves. Applesoft supports drawing in

4505-408: The compatible GW-BASIC to makers of PC clones , and sold copies to retail customers. The company similarly licensed an Applesoft -compatible BASIC to VTech for its Laser 128 clone . Known variants: MBASIC is available for CP/M-80 and ISIS-II . Also available for TEKDOS . MBASIC is a stripped-down BASIC-80 with only hardware-neutral functions. However, due to the popularity of CP/M,

4590-509: The core of Microsoft's 6502 BASIC implementation, which includes using the GET command for detecting key presses and not requiring any spaces on program lines. While Applesoft BASIC is slower than Integer BASIC, it has many features that the older BASIC lacks: Conversely, Applesoft lacks the MOD (remainder) operator from Integer BASIC. Adapting BASIC for the Apple II was a tedious job as Apple received

4675-524: The early home computers gave way to newer designs like the IBM Personal Computer and Macintosh , BASIC was no longer as widely used, although it retained a strong following. The release of Visual Basic reboosted its popularity and it remains in wide use on Microsoft Windows platforms in its most recent incarnation, Visual Basic .NET . The Altair BASIC interpreter was developed by Microsoft founders Paul Allen and Bill Gates using

4760-501: The first two letters of variables names are significant. For example, "LOW" and "LOSS" are treated as the same variable, and attempting to assign a value to "LOSS" overwrites any value assigned to "LOW". A programmer also has to avoid consecutive letters that are Applesoft commands or operations. The name "SCORE" for a variable is interpreted as containing the OR Boolean operator , rendered as SC OR E . "BACKGROUND" contains GR ,

4845-588: The following: Microsoft catalogs from the 1980s also showed the availability of BASIC-68 and BASIC-69 for the Motorola 6800 and 6809 microprocessors respectively, running the FLEX operating systems , and also mention OEM versions for Perkin-Elmer , Ohio Nuclear , Pertec and Societe Occitane d'Electronique systems. It seems likely this is what is also the basis for the Microsoft/Epson BASIC in

4930-494: The form PLTx such that GR, COLOR=, PLOT, HLIN and VLIN are called PLTG, PLTC, PLTP, PLTH, and PLTV, respectively. The command for returning to text mode, known as TEXT in other versions, is simply TEX, and carries the proviso that it has to be the last statement in a program line. Applesoft BASIC 1.x was closer to Microsoft's original 6502 BASIC code than the later Applesoft II; it retained the Memory Size? prompt and displayed

5015-517: The function is always shown being assigned to "dummy" variables, which, without action to set a value by user-code, just receive a meaningless value handed back to them. Even accessed ROM routines that return values (in examples, those that provide the service of PDL() and SCRN() functions) merely have their values stored, by user-routines, in locations that are separately PEEKed in a subsequent statement. Unlike in Integer BASIC and Applesoft II,

5100-412: The great majority of Z80 machines ran MBASIC, rather than a version customized for specific hardware (TRS-80 BASIC was one of the few exceptions). Microsoft's CP/M card for the Apple II included a modified version of MBASIC that incorporated some of the graphics commands from Applesoft BASIC, such as HPLOT , but the full command set is not supported. The first implementation to use an 8-bit variant of

5185-428: The language. Later on, Microsoft released the 12K Extended BASIC, which included double precision 64-bit variables, IF ... THEN ... ELSE structures, user defined functions, more advanced program editing commands, and descriptive error messages as opposed to error numbers. Numeric variables now had three basic types, % denoted 16-bit integers, # denoted 64-bit doubles, and ! denoted 32-bit singles, but this

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5270-519: The later Applesoft II, occupying 8½ KB of memory, instead of the 10 KB used by the later Applesoft II. Consequently, it lacks a number of command features developed for the later, mainstream version: as well as several the later version would have, that had already been present in Apple's Integer BASIC: In addition, its low-resolution graphics commands have different names from their Integer BASIC/Applesoft II counterparts. All command names are of

5355-754: The main language for its OS-9 , the other OS available on the Color Computer (Microware also wrote version 2.0 of Extended Color BASIC when Microsoft refused to do it). Microsoft BASIC was also included in the Dragon 32 / 64 computers that were built in Wales and enjoyed some limited success in the UK home computer market in the early 1980s. Dragon computers were somewhat compatible with the Tandy TRS-80, as they were built on very similar hardware. Microsoft produced

5440-419: The majority of the numerous home and other personal computers of the 1970s and especially the 1980s, and extended along the way. Contrary to the original Altair BASIC, most home computer BASICs are resident in ROM , and thus are available on the machines at power-on in the form of the characteristic " READY ". prompt. Hence, Microsoft's and other variants of BASIC constitute a significant and visible part of

5525-610: The number of elements in the finite set S {\displaystyle S} .) It can be shown that if f {\displaystyle f} is a pseudo-random number generator for the uniform distribution on ( 0 , 1 ) {\displaystyle \left(0,1\right)} and if F {\displaystyle F} is the CDF of some given probability distribution P {\displaystyle P} , then F ∗ ∘ f {\displaystyle F^{*}\circ f}

5610-512: The numbers were written to cards, they would take very much longer to write and read. On the ENIAC computer he was using, the "middle square" method generated numbers at a rate some hundred times faster than reading numbers in from punched cards . The middle-square method has since been supplanted by more elaborate generators. A recent innovation is to combine the middle square with a Weyl sequence . This method produces high-quality output through

5695-414: The original 32-bit version. This new 40-bit format became the most common as it was used on most 6502-based machines of the era. It was also ported to the 16-bit BASIC-86 ( 8086/88 ). The final major release of BASIC-80 was version 5.x, which appeared in 1981 and added support for 40-character variable names, WHILE ... WEND loops, dynamic string allocation, and several other features. BASIC 5.x removed

5780-419: The past 40 years. Perhaps amazingly, it remains as relevant today as it was 40 years ago. As an illustration, consider the widely used programming language Java . Up until 2020, Java still relied on a linear congruential generator (LCG) for its PRNG, which is of low quality (see further below). Java support was upgraded with Java 17 . One well-known PRNG to avoid major problems and still run fairly quickly

5865-512: The programmers, Cliff Huston, used his own IMSAI 8080 computer to cross assemble the BASIC source. Applesoft is similar to Commodore's BASIC 2.0 aside from features inherited from Integer BASIC. There are a few minor differences such as Applesoft's lack of bitwise operators; otherwise most BASIC programs that do not use hardware-dependent features will run on both BASICs. The PR# statement redirects output to an expansion card, and IN# redirects input from an expansion card. The slot number of

5950-473: The quality of the Mersenne Twister, which has a too-large state space and a very slow recovery from state spaces with a large number of zeros. A PRNG suitable for cryptographic applications is called a cryptographically-secure PRNG (CSPRNG). A requirement for a CSPRNG is that an adversary not knowing the seed has only negligible advantage in distinguishing the generator's output sequence from

6035-440: The sake of readability. Since LIST adds a space before and after every tokenized keyword, it often produces two spaces in a row where one would suffice for readability. The default prompt for INPUT is a question mark. PRINT does not add a leading space in front of numbers. Through several early models of the Apple II, Applesoft BASIC did not support the use of lowercase letters in programs, except in strings. PRINT

6120-427: The square of a 4-digit number. This gives "2343" as the "random" number. Repeating this procedure gives "4896" as the next result, and so on. Von Neumann used 10 digit numbers, but the process was the same. A problem with the "middle square" method is that all sequences eventually repeat themselves, some very quickly, such as "0000". Von Neumann was aware of this, but he found the approach sufficient for his purposes and

6205-408: The two-element field; such generators are related to linear-feedback shift registers . The 1997 invention of the Mersenne Twister , in particular, avoided many of the problems with earlier generators. The Mersenne Twister has a period of 2  − 1 iterations (≈ 4.3 × 10 ), is proven to be equidistributed in (up to) 623 dimensions (for 32-bit values), and at the time of its introduction

6290-413: The use of floating-point numbers for all math operations degrades performance. Applesoft BASIC programs are stored as a linked list of lines; a GOTO or GOSUB takes linear time . Some programs have the subroutines at the top to reduce the time for calling them. Unlike Integer BASIC, Applesoft does not convert literal numbers (like 100) in the source code to binary when a line is entered. Rather,

6375-495: Was delivered on paper tape and in its original version took 4  KB of memory. The following functions and statements were available: LIST , NEW , PRINT , INPUT , IF...THEN , FOR...NEXT , SQR , RND , SIN , LET , USR , DATA , READ , REM , CLEAR , STOP , TAB , RESTORE , ABS , END , INT , RETURN , STEP , GOTO , and GOSUB . There were no string variables in 4K BASIC and single-precision 32-bit floating point

6460-435: Was known to be inadequate, but better methods were unavailable. Press et al. (2007) described the result thus: "If all scientific papers whose results are in doubt because of [LCGs and related] were to disappear from library shelves, there would be a gap on each shelf about as big as your fist." A major advance in the construction of pseudorandom generators was the introduction of techniques based on linear recurrences on

6545-580: Was not written by Microsoft as was widely rumored. According to TI Engineer H. Schuurman, "They (in the form of Bob Greenberg of Microsoft) were contracted to develop BASIC for the SR-70 (which is also sometimes referred to as the 99/7), but the BASIC for the 99/4 was developed in-house." TI-99/4 BASIC was based on Dartmouth BASIC and complies to the American National Standard for minimal BASIC (ANSI X3.60-1978). Microsoft ported BASIC-80 to

6630-541: Was released with an updated Microsoft MSDN Web site that included a full teacher curriculum, a Getting Started Guide, and several e-books. Small Basic exists to help students as young as age eight learn the foundations of computer programming and then graduate to Visual Basic via the downloadable software, Visual Studio Express , where they can continue to build on the foundation by learning Visual C# , VB.NET , and Visual C++ . Pseudorandom number generator A pseudorandom number generator ( PRNG ), also known as

6715-451: Was running faster than other statistically reasonable generators. In 2003, George Marsaglia introduced the family of xorshift generators, again based on a linear recurrence. Such generators are extremely fast and, combined with a nonlinear operation, they pass strong statistical tests. In 2006, the WELL family of generators was developed. The WELL generators in some ways improves on

6800-425: Was supplied by Microsoft and its name is derived from the names of both Apple Computer and Microsoft. Apple employees, including Randy Wigginton , adapted Microsoft's interpreter for the Apple II and added several features. The first version of Applesoft was released in 1977 on cassette tape and lacked proper support for high-resolution graphics. Applesoft II , which was made available on cassette and disk and in

6885-469: Was the RANDU random number algorithm used for decades on mainframe computers . It was seriously flawed, but its inadequacy went undetected for a very long time. In many fields, research work prior to the 21st century that relied on random selection or on Monte Carlo simulations, or in other ways relied on PRNGs, were much less reliable than ideal as a result of using poor-quality PRNGs. Even today, caution

6970-427: Was the default format so the ! is rarely seen in programs. The extended 8 KB version was then generalized into BASIC-80 (8080/85, Z80 ), and ported into BASIC-68 ( 6800 ), BASIC-69 ( 6809 ), and 6502 -BASIC. The 6502 had somewhat less dense assembler code and expanded in size to just under 8K for the single precision version, or 9K for a version using an intermediate 40-bit floating point format in place of

7055-436: Was the only numeric type supported. Variable names consisted of one letter (A–Z) or one letter followed by one digit (0–9), thus allowing up to 286 numeric variables. For machines with more memory, the 8 KB version added 31 additional statements and support for string variables and their related operations like MID$ and string concatenation . String variables were denoted with a $ suffix, which remained in later versions of

7140-662: Was unveiled to the public at the West Coast Computer Faire in April 1977 and became available for sale in June. One of the most common customer complaints about the computer was BASIC's lack of floating-point math. Making things more problematic was that the rival Commodore PET personal computer had a floating point-capable BASIC interpreter from the beginning. As Wozniak—the only person who understood Integer BASIC well enough to add floating point features—was busy with

7225-405: Was worried that mathematical "fixes" would simply hide errors rather than remove them. Von Neumann judged hardware random number generators unsuitable, for, if they did not record the output generated, they could not later be tested for errors. If they did record their output, they would exhaust the limited computer memories then available, and so the computer's ability to read and write numbers. If

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