Altair BASIC is a discontinued interpreter for the BASIC programming language that ran on the MITS Altair 8800 and subsequent S-100 bus computers. It was Microsoft's first product, distributed by MITS under a contract. Altair BASIC was the start of the Microsoft BASIC product range. Bill Gates recalls that, when he and Paul Allen read about the Altair in the January 1975 issue of Popular Electronics, they understood that the price of computers would soon drop to the point that selling software for them would be a profitable business. Gates believed that, by providing a BASIC interpreter for the new computer, they could make it more attractive to hobbyists, they contacted MITS founder Ed Roberts, told him that they were developing an interpreter, asked whether he would like to see a demonstration. This followed the questionable engineering industry practice of a trial balloon, an announcement of a non-existent product to gauge interest. Roberts agreed to meet them for a demonstration in a few weeks, in March 1975.
Gates and Allen had neither an interpreter nor an Altair system on which to develop and test one. However, Allen had written an Intel 8008 emulator for their previous venture Traf-O-Data that ran on a PDP-10 time-sharing computer, he adapted this emulator based on the Altair programmer guide, they developed and tested the interpreter on Harvard's PDP-10. Harvard officials were not pleased when they found out, but there was no written policy that covered the use of this computer. Gates and Allen bought computer time from a timesharing service in Boston to complete their BASIC program debugging, they hired Harvard student Monte Davidoff to write floating-point arithmetic routines for the interpreter, a feature not available in many of its competitors. The finished interpreter, including its own I/O system and line editor, fit in only four kilobytes of memory, leaving plenty of room for the interpreted program. In preparation for the demo, they stored the finished interpreter on a punched tape that the Altair could read, Paul Allen flew to Albuquerque.
On final approach, Allen realized that they had forgotten to write a bootstrap program to read the tape into memory. Writing in 8080 machine language, Allen finished the program. Only when they loaded the program onto an Altair and saw a prompt asking for the system's memory size did Gates and Allen know that their interpreter worked on the Altair hardware, they made a bet on who could write the shortest bootstrap program, Gates won. Roberts agreed to distribute the interpreter, he hired Gates and Allen to maintain and improve it, causing Gates to take a leave of absence from Harvard. They produced several versions: the original 4K BASIC and 8K BASIC, Extended BASIC, Extended ROM BASIC, Disk BASIC; the smallest version, 4K BASIC, was able to run within a 4k RAM machine, leaving only about 790 bytes free for program code. To make the language fit in such a small space, the 4K version lacked string handling and stripped out a number of the mathematical functions; these were added back into the 8K BASIC, which had the string library, a larger set of math functions including RND for random numbers, boolean operators, PEEK and POKE.
The 8K version is the basis for most versions of BASIC during the home computer era. Extended BASIC added PRINT USING and basic disk commands, while Disk BASIC further extended the disk commands to allow raw I/O. In October 1975, 4K BASIC sold for $150, 8K BASIC for $200, Extended BASIC for $350; the prices were discounted to $60, $75, $150 for those who purchased "8K of Altair memory, an Altair I/O board." The language versions were available on cassette tape. As they expected, the Altair was popular with hobbyists such as the Homebrew Computer Club. Altair BASIC, as MITS' preferred BASIC interpreter, was popular. However, the hobbyists took a "share-alike" approach to software and thought nothing of copying the BASIC interpreter for other hobbyists. Homebrew member Dan Sokol was prolific. Gates responded in 1976 with a worded Open Letter to Hobbyists that accused the copiers of theft and declared that he could not continue developing computer software that people did not pay for. Many hobbyists reacted defensively to the letter.
Under the terms of the purchase agreement, MITS would receive the rights to the interpreter after it had paid a certain amount in royalties. However, Microsoft had developed versions of the interpreter for other systems such as the Motorola 6800; when they decided to leave MITS, a dispute arose over whether the full amount had been paid and whether the agreement applied to the other versions. Microsoft and MITS took the dispute to an arbitrator who, much to Roberts' surprise, decided in favor of Microsoft based on MITS failure to market the software with their "best efforts". BASIC interpreters remained the core of Microsoft's business until the early 1980s, when it shifted to MS-DOS. Microsoft Binary Format Freiberger, Paul. Fire in the Valley: The Making of the Personal Computer. New York, NY: McGraw Hill. ISBN 0-07-135892-7. Gates, Bill; the Road Ahead. New York: Viking. ISBN 0-670-77289-5. Cringely, Robert X.. Triumph of the Nerds. PBS, 1996. Bunnell, David. "Altair BASIC — Up and Running". Computer Notes.
Altair Users Group, MITS Inc. 1: 1, 3. Archived from the original on March 23, 2012. Retrieved 2007-04-18. Altair BASIC 3.2 - Annotated Disassembly Altair BASIC source disassembly, compiled by Reuben Harris and archived at archive.org Writing an Altair Basic, Interview with
Colorado is a state of the Western United States encompassing most of the southern Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains. It is the 8th most extensive and 21st most populous U. S. state. The estimated population of Colorado was 5,695,564 on July 1, 2018, an increase of 13.25% since the 2010 United States Census. The state was named for the Colorado River, which early Spanish explorers named the Río Colorado for the ruddy silt the river carried from the mountains; the Territory of Colorado was organized on February 28, 1861, on August 1, 1876, U. S. President Ulysses S. Grant signed Proclamation 230 admitting Colorado to the Union as the 38th state. Colorado is nicknamed the "Centennial State" because it became a state one century after the signing of the United States Declaration of Independence. Colorado is bordered by Wyoming to the north, Nebraska to the northeast, Kansas to the east, Oklahoma to the southeast, New Mexico to the south, Utah to the west, touches Arizona to the southwest at the Four Corners.
Colorado is noted for its vivid landscape of mountains, high plains, canyons, plateaus and desert lands. Colorado is part of the western and southwestern United States, is one of the Mountain States. Denver is most populous city of Colorado. Residents of the state are known as Coloradans, although the antiquated term "Coloradoan" is used. Colorado is notable for its diverse geography, which includes alpine mountains, high plains, deserts with huge sand dunes, deep canyons. In 1861, the United States Congress defined the boundaries of the new Territory of Colorado by lines of latitude and longitude, stretching from 37°N to 41°N latitude, from 102°02'48"W to 109°02'48"W longitude. After 158 years of government surveys, the borders of Colorado are now defined by 697 boundary markers and 697 straight boundary lines. Colorado and Utah are the only states that have their borders defined by straight boundary lines with no natural features; the southwest corner of Colorado is the Four Corners Monument at 36°59'56"N, 109°2'43"W.
This is the only place in the United States where four states meet: Colorado, New Mexico and Utah. The summit of Mount Elbert at 14,440 feet elevation in Lake County is the highest point in Colorado and the Rocky Mountains of North America. Colorado is the only U. S. state that lies above 1,000 meters elevation. The point where the Arikaree River flows out of Yuma County and into Cheyenne County, Kansas, is the lowest point in Colorado at 3,317 feet elevation; this point, which holds the distinction of being the highest low elevation point of any state, is higher than the high elevation points of 18 states and the District of Columbia. A little less than half of Colorado is flat and rolling land. East of the Rocky Mountains are the Colorado Eastern Plains of the High Plains, the section of the Great Plains within Nebraska at elevations ranging from 3,350 to 7,500 feet; the Colorado plains are prairies but include deciduous forests and canyons. Precipitation averages 15 to 25 inches annually. Eastern Colorado is presently farmland and rangeland, along with small farming villages and towns.
Corn, hay and oats are all typical crops. Most villages and towns in this region boast both a grain elevator. Irrigation water is available from subterranean sources. Surface water sources include the South Platte, the Arkansas River, a few other streams. Subterranean water is accessed through artesian wells. Heavy use of wells for irrigation caused underground water reserves to decline. Eastern Colorado hosts considerable livestock, such as hog farms. 70% of Colorado's population resides along the eastern edge of the Rocky Mountains in the Front Range Urban Corridor between Cheyenne and Pueblo, Colorado. This region is protected from prevailing storms that blow in from the Pacific Ocean region by the high Rockies in the middle of Colorado; the "Front Range" includes Denver, Fort Collins, Castle Rock, Colorado Springs, Pueblo and other townships and municipalities in between. On the other side of the Rockies, the significant population centers in Western Colorado are the cities of Grand Junction and Montrose.
The Continental Divide of the Americas extends along the crest of the Rocky Mountains. The area of Colorado to the west of the Continental Divide is called the Western Slope of Colorado. West of the Continental Divide, water flows to the southwest via the Colorado River and the Green River into the Gulf of California. Within the interior of the Rocky Mountains are several large parks which are high broad basins. In the north, on the east side of the Continental Divide is the North Park of Colorado; the North Park is drained by the North Platte River, which flows north into Nebraska. Just to the south of North Park, but on the western side of the Continental Divide, is the Middle Park of Colorado, drained by the Colorado River; the South Park of Colorado is the region of the headwaters of the South Platte River. In southmost Colorado is the large San Luis Valley, where the headwaters of the Rio Grande are located; the valley sits between the Sangre De Cristo Mountains and San Juan Mountains, consists of large desert lands that run into the mountains.
The Rio Grande drains due south into New Mexico and Texas. Across the Sangre de Cristo Range to the east of the S
An operating system is system software that manages computer hardware and software resources and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may include accounting software for cost allocation of processor time, mass storage and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is executed directly by the hardware and makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer – from cellular phones and video game consoles to web servers and supercomputers; the dominant desktop operating system is Microsoft Windows with a market share of around 82.74%. MacOS by Apple Inc. is in second place, the varieties of Linux are collectively in third place. In the mobile sector, use in 2017 is up to 70% of Google's Android and according to third quarter 2016 data, Android on smartphones is dominant with 87.5 percent and a growth rate 10.3 percent per year, followed by Apple's iOS with 12.1 percent and a per year decrease in market share of 5.2 percent, while other operating systems amount to just 0.3 percent.
Linux distributions are dominant in supercomputing sectors. Other specialized classes of operating systems, such as embedded and real-time systems, exist for many applications. A single-tasking system can only run one program at a time, while a multi-tasking operating system allows more than one program to be running in concurrency; this is achieved by time-sharing, where the available processor time is divided between multiple processes. These processes are each interrupted in time slices by a task-scheduling subsystem of the operating system. Multi-tasking may be characterized in co-operative types. In preemptive multitasking, the operating system slices the CPU time and dedicates a slot to each of the programs. Unix-like operating systems, such as Solaris and Linux—as well as non-Unix-like, such as AmigaOS—support preemptive multitasking. Cooperative multitasking is achieved by relying on each process to provide time to the other processes in a defined manner. 16-bit versions of Microsoft Windows used cooperative multi-tasking.
32-bit versions of both Windows NT and Win9x, used preemptive multi-tasking. Single-user operating systems have no facilities to distinguish users, but may allow multiple programs to run in tandem. A multi-user operating system extends the basic concept of multi-tasking with facilities that identify processes and resources, such as disk space, belonging to multiple users, the system permits multiple users to interact with the system at the same time. Time-sharing operating systems schedule tasks for efficient use of the system and may include accounting software for cost allocation of processor time, mass storage and other resources to multiple users. A distributed operating system manages a group of distinct computers and makes them appear to be a single computer; the development of networked computers that could be linked and communicate with each other gave rise to distributed computing. Distributed computations are carried out on more than one machine; when computers in a group work in cooperation, they form a distributed system.
In an OS, distributed and cloud computing context, templating refers to creating a single virtual machine image as a guest operating system saving it as a tool for multiple running virtual machines. The technique is used both in virtualization and cloud computing management, is common in large server warehouses. Embedded operating systems are designed to be used in embedded computer systems, they are designed to operate on small machines like PDAs with less autonomy. They are able to operate with a limited number of resources, they are compact and efficient by design. Windows CE and Minix 3 are some examples of embedded operating systems. A real-time operating system is an operating system that guarantees to process events or data by a specific moment in time. A real-time operating system may be single- or multi-tasking, but when multitasking, it uses specialized scheduling algorithms so that a deterministic nature of behavior is achieved. An event-driven system switches between tasks based on their priorities or external events while time-sharing operating systems switch tasks based on clock interrupts.
A library operating system is one in which the services that a typical operating system provides, such as networking, are provided in the form of libraries and composed with the application and configuration code to construct a unikernel: a specialized, single address space, machine image that can be deployed to cloud or embedded environments. Early computers were built to perform a series of single tasks, like a calculator. Basic operating system features were developed in the 1950s, such as resident monitor functions that could automatically run different programs in succession to speed up processing. Operating systems did not exist in their more complex forms until the early 1960s. Hardware features were added, that enabled use of runtime libraries and parallel processing; when personal computers became popular in the 1980s, operating systems were made for them similar in concept to those used on larger computers. In the 1940s, the earliest electronic digital systems had no operating systems.
Electronic systems of this time were programmed on rows of mechanical switches or by jumper wires on plug boards. These were special-purpose systems that, for example, generated ballistics tables for the military or controlled the pri
The Hewlett-Packard Company or Hewlett-Packard was an American multinational information technology company headquartered in Palo Alto, California. It developed and provided a wide variety of hardware components as well as software and related services to consumers, small- and medium-sized businesses and large enterprises, including customers in the government and education sectors; the company was founded in a one-car garage in Palo Alto by Bill Hewlett and David Packard, produced a line of electronic test equipment. HP was the world's leading PC manufacturer from 2007 to Q2 2013, at which time Lenovo ranked ahead of HP. HP specialized in developing and manufacturing computing, data storage, networking hardware, designing software and delivering services. Major product lines included personal computing devices and industry standard servers, related storage devices, networking products, software and a diverse range of printers and other imaging products. HP directly marketed its products to households, small- to medium-sized businesses and enterprises as well as via online distribution, consumer-electronics and office-supply retailers, software partners and major technology vendors.
HP had services and consulting business around its products and partner products. Hewlett-Packard company events included the spin-off of its electronic and bio-analytical measurement instruments part of its business as Agilent Technologies in 1999, its merger with Compaq in 2002, the acquisition of EDS in 2008, which led to combined revenues of $118.4 billion in 2008 and a Fortune 500 ranking of 9 in 2009. In November 2009, HP announced the acquisition of 3Com, with the deal closing on April 12, 2010. On April 28, 2010, HP announced the buyout of Inc. for $1.2 billion. On September 2, 2010, HP won its bidding war for 3PAR with a $33 a share offer, which Dell declined to match. Hewlett-Packard spun off its enterprise products and services business as Hewlett Packard Enterprise on November 1, 2015. Hewlett-Packard held onto the PC and printer businesses, was renamed to HP Inc. Bill Hewlett and David Packard graduated with degrees in electrical engineering from Stanford University in 1935; the company originated in a garage in nearby Palo Alto during a fellowship they had with a past professor, Frederick Terman at Stanford during the Great Depression.
They considered Terman a mentor in forming Hewlett-Packard. In 1938, Packard and Hewlett begin part-time work in a rented garage with an initial capital investment of US$538. In 1939 Hewlett and Packard decided to formalize their partnership, they tossed a coin to decide whether the company they founded would be called Hewlett-Packard or Packard-Hewlett. HP incorporated on August 18, 1947, went public on November 6, 1957. Of the many projects they worked on, their first financially successful product, was a precision audio oscillator, the Model HP200A, their innovation was the use of a small incandescent light bulb as a temperature dependent resistor in a critical portion of the circuit, the negative feedback loop which stabilized the amplitude of the output sinusoidal waveform. This allowed them to sell the Model 200A for $89.40 when competitors were selling less stable oscillators for over $200. The Model 200 series of generators continued production until at least 1972 as the 200AB, still tube-based but improved in design through the years.
One of the company's earliest customers was Walt Disney Productions, which bought eight Model 200B oscillators for use in certifying the Fantasound surround sound systems installed in theaters for the movie Fantasia. They worked on counter-radar technology and artillery shell fuses during World War II, which allowed Packard to be exempt from the draft. HP is recognized as the symbolic founder of Silicon Valley, although it did not investigate semiconductor devices until a few years after the "traitorous eight" had abandoned William Shockley to create Fairchild Semiconductor in 1957. Hewlett-Packard's HP Associates division, established around 1960, developed semiconductor devices for internal use. Instruments and calculators were some of the products using these devices. During the 1960s, HP partnered with Sony and the Yokogawa Electric companies in Japan to develop several high-quality products; the products were not a huge success, as there were high costs in building HP-looking products in Japan.
HP and Yokogawa formed a joint venture in 1963 to market HP products in Japan. HP bought Yokogawa Electric's share of Hewlett-Packard Japan in 1999. HP spun off Dynac, to specialize in digital equipment; the name was picked so that the HP logo "hp" could be turned upside down to be a reverse reflect image of the logo "dy" of the new company. Dynac changed to Dymec, was folded back into HP in 1959. HP experimented with using Digital Equipment Corporation minicomputers with its instruments, but after deciding that it would be easier to build another small design team than deal with DEC, HP entered the computer market in 1966 with the HP 2100 / HP 1000 series of minicomputers; these had a simple accumulator-based design, with two accumulator registers and, in the HP 1000 models, two index registers. The series was produced for 20 years, in spite of several attempts to replace it, was a forerunner of the HP 9800 and HP 250 series of desktop and business computers; the HP 3000 was an advanced stack-based design for a business computing server redesigned with RISC technology.
The HP 2640 series of smart and intelligent terminals introduced forms-based interfaces to ASCII terminals, introduced screen labeled functio
HP-UX is Hewlett Packard Enterprise's proprietary implementation of the Unix operating system, based on UNIX System V and first released in 1984. Recent versions support the HP 9000 series of computer systems, based on the PA-RISC instruction set architecture, HP Integrity systems, based on Intel's Itanium architecture. Earlier versions of HP-UX supported the HP Integral PC and HP 9000 Series 200, 300, 400 computer systems based on the Motorola 68000 series of processors, as well as the HP 9000 Series 500 computers based on HP's proprietary FOCUS architecture. HP-UX was the first Unix to offer access control lists for file access permissions as an alternative to the standard Unix permissions system. HP-UX was among the first Unix systems to include a built-in logical volume manager. HP has had a long partnership with Veritas Software, uses VxFS as the primary file system, it is one of six commercial operating systems that have versions certified to The Open Group's UNIX 03 standard. HP-UX 11i offers a common root disk for its clustered file system.
HP Serviceguard is the cluster solution for HP-UX. HP Global Workload Management adjusts workloads to optimize performance, integrates with Instant Capacity on Demand so installed resources can be paid for in 30-minute increments as needed for peak workload demands. HP-UX offers operating system-level virtualization features such as hardware partitions, isolated OS virtual partitions on cell-based servers, HP Integrity Virtual Machines on all Integrity servers. HPVM supports guests running on HP-UX 11i v3 hosts – guests can run Linux, OpenVMS 8.4 or HP-UX. HP supports online VM guest migration, where encryption can secure the guest contents during migration. HP-UX 11i v3 scales as follows: 256 processor cores 8 TB main memory 32 TB maximum file system 16 TB maximum file size 128 million ZB—16 million logical units each up to 8ZB. "HP-UX 11i v3". Retrieved 2017-10-31; the 11i v2 release introduced kernel-based intrusion detection, strong random number generation, stack buffer overflow protection, security partitioning, role-based access management, various open-source security tools.
HP classifies the operating system's security features into three categories: data and identity: Release 6.x introduced the context dependent files feature, a method of allowing a fileserver to serve different configurations and binaries to different client machines in a heterogeneous environment. A directory containing such files had its suid bit set and was made hidden from both ordinary and root processes under normal use; such a scheme was sometimes exploited by intruders to hide malicious data. CDFs and the CDF filesystem were dropped with release 10.0. HP-UX operating systems supports a variety of PA-RISC systems; the 11.0 added support for Integrity-based servers for the transition from PA-RISC to Itanium. HP-UX 11i v1.5 is the first version. On the introduction of HP-UX 11i v2 the operating system supported both of these architectures. HP-UX 11i supports HP Integrity Servers of HP BL server blade family; these servers use the Intel Itanium architecture. HP-UX 11i v2 and 11i v3 support HP's CX series servers.
CX stands for carrier grade and is used for telco industry with -48V DC support and is NEBS certified. Both of these systems are discontinued. HP-UX supports HP's RX series of servers. Prior to the release of HP-UX version 11.11, HP used a decimal version numbering scheme with the first number giving the major release and the number following the decimal showing the minor release. With 11.11, HP made a marketing decision to name their releases 11i followed by a v for the version. The i was intended to indicate the OS is Internet-enabled, but the effective result was a dual version-numbering scheme. 1.0 First release for HP 9000 Series 500. HP-UX for Series 500 was different that HP-UX for any other HP machines, as it was layered atop a Series 500 specific operating system called SUNOS. 1.0 AT&T System III based. Support for the HP Integral PC; the kernel runs from ROM. 2.0 First release for HP's early Motorola 68000-based workstations 5.0 ROM-based AT&T System V for the HP Integral PC. Distinct from a HP-UX 5.x for Series 200/300.
3.x HP 9000 Series 600/800 only. Note: 2.x/3.x were developed in parallel with 5.x/6.x, so, for example, 3.x was contemporary with 6.x. The two lines were united at HP-UX 7.x. 6.x Support for HP 9000 Series 300 only. Introduced sockets from 4.3BSD. This version introduced the above-discussed context dependent files, which were removed in release 10 because of their security risks. 7.x Support for HP 9000 Series 300/400, 600/700 /800 HP systems. Provided OSF/Motif. 8.x Support for HP 9000 Series 300/400 600/700/800 systems. Shared libraries introduced. 9.x 9.00, 9.02, 9.04, 9.01, 9.03, 9.05, 9.07, 9.08, 9.09, 9.09+, 9.10. These provided support for the HP 9000 800 systems. Introduced System Administration Manager; the Logical Volume Manager was presented in 9.00 for the Series 800. 10.0 This major release saw a convergence of the operating system between the HP 9000 Series 700 and Series 800 systems, dropping suppor
The IBM Personal Computer Basic shortened to IBM BASIC, is a programming language first released by IBM with the IBM Personal Computer in 1981. IBM released four different versions of the Microsoft BASIC interpreter, licensed from Microsoft for the PC and PCjr, they are known as Cassette BASIC, Disk BASIC, Advanced BASIC, Cartridge BASIC. Versions of Disk BASIC and Advanced BASIC were included with IBM PC DOS up to PC DOS 4. In addition to the features of an ANSI standard BASIC, the IBM versions offered support for the graphics and sound hardware of the IBM PC line. Source code could be typed in with a full screen editor, limited facilities were provided for rudimentary program debugging. IBM released a version of the Microsoft BASIC compiler for the PC, concurrently with the release of PC DOS 1.10 in 1982. IBM licensed Microsoft BASIC for the PC despite having its own version for the company's mainframes. Don Estridge said, "Microsoft BASIC had hundreds of thousands of users around the world.
How are you going to argue with that?" IBM Cassette BASIC came in 32 kilobytes of read-only memory, separate from the 8 KB BIOS ROM of the original IBM PC, did not require an operating system to run. Cassette BASIC provided the default user interface invoked by the BIOS through INT 18h if there was no floppy disk drive installed, or if the boot code did not find a bootable floppy disk at power up; the name Cassette BASIC came from its use of cassette tapes rather than floppy disks to store programs and data. Cassette BASIC was built into the ROMs of the original PC and XT, early models in the PS/2 line, it only supported loading and saving programs to the IBM cassette tape interface, unavailable on models after the original Model 5150. The entry-level version of the 5150 came with just 16 KB of random-access memory, sufficient to run Cassette BASIC. However, Cassette BASIC was used because few PCs were sold without a disk drive, most were sold with PC DOS and sufficient RAM to at least run Disk BASIC—many could run Advanced BASIC as well.
There were three versions of Cassette BASIC: C1.00, C1.10, C1.20. IBM Disk BASIC was included in the original IBM PC DOS; because it uses the 32 KB Cassette BASIC ROM, BASIC. COM did not run on highly compatible PC clones such as the Compaq Portable; the name Disk BASIC came from its use of floppy disks as well as cassette tapes to store programs and data. Disk-based code corrected errata in the ROM-resident code and added floppy disk and serial port support. Disk BASIC could be identified by its use of the letter D preceding the version number, it added disk support and some features lacking in Cassette BASIC, but did not include the extended sound/graphics functions of BASICA. The primary purpose of Disk BASIC was as a "lite" version for IBM PCs with only 48K of memory: BASIC. COM would have about 23K free for user code, whereas BASICA would only have about 17K. By 1986, all new PCs shipped with at least 256k and DOS versions after 3.00 reduced Disk BASIC to only a small stub that called BASICA.
COM for compatibility with batch files. With all this excess RAM, BASIC would still only allocate and manage just under 61K for user programs. IBM Advanced BASIC was included in the original IBM PC DOS, required the ROM-resident code of Cassette BASIC, it added functions such as diskette file access, storing programs on disk, monophonic sound using the PC's built-in speaker, graphics functions to set and clear pixels, draw lines and circles, set colors, event handling for communications and joystick presses. BASICA would not run on non-IBM computers or IBM models, since those lack the needed ROM BASIC. BASICA versions were the same as their respective DOS, beginning with v1.00 and ending with v3.30. The early versions of BASICA did not support subdirectories and some graphics commands functioned differently; as an example, if the LINE statement was used to draw lines that trailed off-screen, BASIC would intersect them with the nearest adjacent line while in BASIC 2.x and up, they went off the screen and did not intersect.
The PAINT command in BASIC 1.x begins filling at the coordinate specified and expands outward in alternating up and down directions while in BASIC 2.x it fills everything below the starting coordinate and after finishing, everything above it. BASIC 1.x's PAINT command makes use of the system stack for storage and when filling in complex areas, it was possible to produce an OVERFLOW error. To remedy this, the CLEAR statement can be used to expand BASIC's stack. BASIC 2.x does not use the stack when thus is free of this problem. Compaq BASIC 1.13 was the first standalone BASIC for the PC as well as the only version of BASIC besides IBM BASICA 1.00 and 1.10 to use FCBs and include the original LINE statement with intersecting lines. Early versions of PC DOS included several sample BASIC programs demonstrating the capabilities of the PC, including the BASICA game DONKEY. BAS. GW-BASIC is identical to BASICA, with the exception of including the Cassette BASIC code in the program, thus allowing it to run on non-IBM computers and IBM models that lack Cassette BASIC in ROM.
A ROM cartridge version of BASIC was only available on the IBM PCjr and supported the additional graphics modes and sound capa
IEEE 488 is a short-range digital communications 8-bit parallel multi-master interface bus specification. IEEE 488 was created as HP-IB and is called GPIB, it has been the subject of several standards. Although created in the late 1960s to connect together automated test equipment, it had some success during the 1970s and 1980s as a peripheral bus for early microcomputers, notably the Commodore PET. Newer standards have replaced IEEE 488 for computer use, but it still sees some use in the test equipment field. In the late 1960s, Hewlett-Packard manufactured various automated test and measurement instruments, such as digital multimeters and logic analyzers, they developed the HP Interface Bus to enable easier interconnection between instruments and controllers. The bus was easy to implement using the technology at the time, using a simple parallel bus and several individual control lines. For example, the HP 59501 Power Supply Programmer and HP 59306A Relay Actuator were both simple HP-IB peripherals implemented only in TTL, using no microprocessor.
HP licensed the HP-IB patents for a nominal fee to other manufacturers. It became known as the General Purpose Interface Bus, became a de facto standard for automated and industrial instrument control; as GPIB became popular, it was formalized by various standards organizations. In 1975, the IEEE standardized the bus as Standard Digital Interface for Programmable Instrumentation, IEEE 488; the standard was revised in 1987, redesignated as IEEE 488.1. These standards formalized the mechanical and basic protocol parameters of GPIB, but said nothing about the format of commands or data. In 1987, IEEE introduced Standard Codes, Formats and Common Commands, IEEE 488.2. It was revised in 1992. IEEE 488.2 provided for basic syntax and format conventions, as well as device-independent commands, data structures, error protocols, the like. IEEE 488.2 built on IEEE 488.1 without superseding it. While IEEE 488.1 defined the hardware and IEEE 488.2 defined the protocol, there was still no standard for instrument-specific commands.
Commands to control the same class of instrument, e.g. multimeters, would vary between manufacturers and models. The United States Air Force, Hewlett-Packard, recognized this problem. In 1989, HP developed their TML language, the forerunner to Standard Commands for Programmable Instrumentation. SCPI was introduced as an industry standard in 1990. SCPI added standard generic commands, a series of instrument classes with corresponding class-specific commands. SCPI allowed other physical transports; the IEC developed their own standards in parallel with the IEEE, with IEC 60625-1 and IEC 60625-2 replaced by IEC 60488. National Instruments introduced a backward-compatible extension to IEEE 488.1 known as HS-488. It increased the maximum data rate to 8 Mbyte/s, although the rate decreases as more devices are connected to the bus; this was incorporated over HP's objections. In 2004, the IEEE and IEC combined their respective standards into a "Dual Logo" IEEE/IEC standard IEC 60488-1, Standard for Higher Performance Protocol for the Standard Digital Interface for Programmable Instrumentation - Part 1: General, replaces IEEE 488.1/IEC 60625-1, IEC 60488-2,Part 2: Codes, Formats and Common Commands, replaces IEEE 488.2/IEC 60625-2.
IEEE 488 is an electrically parallel bus. The bus employs sixteen signal lines — eight used for bi-directional data transfer, three for handshake, five for bus management — plus eight ground return lines; every device on the bus has a unique 5-bit primary address, in the range from 0 to 30. The standard allows up to 15 devices to share a single physical bus of up to 20 meters total cable length; the physical topology can be star. Active extenders allow longer buses, with up to 31 devices theoretically possible on a logical bus. Control and data transfer functions are logically separated, it is possible for multiple controllers to share the same bus. In the original protocol, transfers use an three-wire ready -- valid -- accepted handshake; the maximum data rate is about one megabyte per second. The HS-488 extension relaxes the handshake requirements, allowing up to 8 Mbyte/s; the slowest participating device determines the speed of the bus. IEEE 488 specifies a 24-pin Amphenol-designed micro ribbon connector.
Micro ribbon connectors are larger than D-subminiature connectors. They are sometimes called "Centronics connectors" after the 36-pin micro ribbon connector Centronics used for their printers. One unusual feature of IEEE 488 connectors is they use a "double-headed" design, with male on one side, female on the other; this allows stacking connectors for easy daisy-chaining. Mechanical considerations limit the number of stacked connectors to four or fewer, although a workaround involving physically supporting the connectors may be able to get around this, they are held in place by either UTS or metric M3.5 × 0.6 threads. Early versions of the standard suggested that metric screws should be blackened to avoid confusion with the incompatible UTS threads. Howev