Misplaced Pages

#568431

126-589: With the original TRS-80 Model I of 1977, TRSDOS was primarily a way of extending the MBASIC ( BASIC in ROM ) with additional I/O (input/output) commands that worked with disk files rather than the cassette tapes that were used by non-disk Model I systems. Later disk-equipped Model III computers used a completely different version of TRSDOS by Radio Shack which culminated in 1981 with TRSDOS Version 1.3. From 1983 disk-equipped TRS-80 Model 4 computers used TRSDOS Version 6, which

252-519: A sigil , and values are often identified as strings by being delimited by "double quotation marks". Arrays in BASIC could contain integers, floating point or string variables. Some dialects of BASIC supported matrices and matrix operations , which can be used to solve sets of simultaneous linear algebraic equations. These dialects would directly support matrix operations such as assignment, addition, multiplication (of compatible matrix types), and evaluation of

378-519: A visual forms builder . This reignited use of the language and "VB" remains a major programming language in the form of VB.NET , while a hobbyist scene for BASIC more broadly continues to exist. John G. Kemeny was the chairman of the Dartmouth College Mathematics Department. Based largely on his reputation as an innovator in math teaching, in 1959 the college won an Alfred P. Sloan Foundation award for $ 500,000 to build

504-742: A $ 300,000 grant from the National Science Foundation , which was used to purchase a GE-225 computer for processing, and a Datanet-30 realtime processor to handle the Teletype Model 33 teleprinters used for input and output. A team of a dozen undergraduates worked on the project for about a year, writing both the DTSS system and the BASIC compiler. The first version BASIC language was released on 1 May 1964. Initially, BASIC concentrated on supporting straightforward mathematical work, with matrix arithmetic support from its initial implementation as

630-669: A BASIC for the PDP-8 , which was a major success in the education market. By the early 1970s, FOCAL and JOSS had been forgotten and BASIC had become almost universal in the minicomputer market. DEC would go on to introduce their updated version, BASIC-PLUS , for use on the RSTS/E time-sharing operating system. During this period a number of simple text-based games were written in BASIC, most notably Mike Mayfield's Star Trek . David Ahl collected these, some ported from FOCAL, and published them in an educational newsletter he compiled. He later collected

756-472: A batch language, and character string functionality being added by 1965. Usage in the university rapidly expanded, requiring the main CPU to be replaced by a GE-235, and still later by a GE-635. By the early 1970s there were hundreds of terminals connected to the machines at Dartmouth, some of them remotely. Wanting use of the language to become widespread, its designers made the compiler available free of charge. In

882-466: A determinant. Many microcomputer BASICs did not support this data type; matrix operations were still possible, but had to be programmed explicitly on array elements. New BASIC programmers on a home computer might start with a simple program, perhaps using the language's PRINT statement to display a message on the screen; a well-known and often-replicated example is Kernighan and Ritchie 's "Hello, World!" program : An infinite loop could be used to fill

1008-646: A disk drive or disk operating system at release. The first version of TRSDOS, by Randy Cook, was so buggy that others wrote alternatives, including NewDOS and LDOS. After disputes with Cook over ownership of the source code , Tandy hired Logical Systems, LDOS's developer, to continue TRSDOS development. TRSDOS 6, shipped with the TRS-80 Model 4 in 1983, is identical to LDOS 6.00. RadioShack's Z80-based line of TRS-80 computers ( Models I/III and Model 4 ) support up to four physical floppy (mini-diskette) drives which (as sold) use 5¼-inch diskettes . The original TRSDOS for

1134-467: A drive is divided up into addressable units. The layer(s) of magnetic particles on the surface of the disk media are magnetized (during the format process) into concentric circles of storage areas called TRACKS . Each track is divided into 256-byte sub-areas called SECTORS . Each sector is uniquely identified by a pattern of information preceding each sector called an ID FIELD . Although the number of sectors per track may vary from one media type to another,

1260-415: A file's allocated disk space(s) is/are to the directory cylinder, and how fragmented (extents located in non-contiguous space(s)) the file is as a whole. The farther away the directory cylinder is, the more the drive's read/write head will need to move, which slows disk access and produces more mechanical wear on the drive. TRSDOS has commands permitting the user to optimize placement of particular files on

1386-410: A loop: DO 100 , I = 1 , 10 , 2 . Is it '1, 10, 2' or '1, 2, 10', and is the comma after the line number required or not?" Moreover, the lack of any sort of immediate feedback was a key problem; the machines of the era used batch processing and took a long time to complete a run of a program. While Kurtz was visiting MIT , John McCarthy suggested that time-sharing offered a solution;

SECTION 10

#1733084570569

1512-455: A machine capable of running between 16 and 32 users at the same time. The system, bundled as the HP 2000, was the first mini platform to offer time-sharing and was an immediate runaway success, catapulting HP to become the third-largest vendor in the minicomputer space, behind DEC and Data General (DG). DEC, the leader in the minicomputer space since the mid-1960s, had initially ignored BASIC. This

1638-509: A map of I/O links and routes. Under DOS and UNIX printing a file can be done with redirection; under UNIX it is normally done by spooling the file to the " line printer " (using the lpr command) because UNIX is conventionally a multi-user system. TRSDOS/LS-DOS 6.x print jobs can be redirected (such as to a disk file) by applying the LINK or ROUTE commands to the system *PR device. TRSDOS/LS-DOS 6.x do not support subdirectories or user areas. However,

1764-513: A mount point for a volume as a path within another volume, the following criteria must be met: By default, Windows will assign drive letters to all drives, as follows: Because of this legacy convention, the operating system startup drive is still most commonly assigned "C:", however this is not always the case. Since personal computers now no longer include floppies, and optical disc and other removable drives typically still start at "D:", letters A and B are available for manual assignment by

1890-417: A new department building. Thomas E. Kurtz had joined the department in 1956, and from the 1960s Kemeny and Kurtz agreed on the need for programming literacy among students outside the traditional STEM fields. Kemeny later noted that "Our vision was that every student on campus should have access to a computer , and any faculty member should be able to use a computer in the classroom whenever appropriate. It

2016-477: A non-system data disk). LDOS and TRSDOS 6 have a SYSRES command which loads selected system files into Z80 RAM, thus freeing space on the system disk for non-system data. All versions have variants of the SYSTEM command which can reassign logical drive numbers to physical drives. It is possible to assign drive numbers such that a physical drive is unassigned a logical drive number; this is sometimes useful to guarantee that

2142-433: A number of these into book form, 101 BASIC Computer Games , published in 1973. During the same period, Ahl was involved in the creation of a small computer for education use, an early personal computer . When management refused to support the concept, Ahl left DEC in 1974 to found the seminal computer magazine, Creative Computing . The book remained popular, and was re-published on several occasions. The introduction of

2268-464: A physical disk drive, it can still be accessed with an operating system's logical interface. However, a volume differs from a partition. A volume is not the same thing as a partition. For example, a floppy disk might be accessible as a volume, even though it does not contain a partition, as floppy disks cannot be partitioned with most modern computer software. Also, an OS can recognize a partition without recognizing any volume associated with it, as when

2394-529: A printer, a serial port , or a video display device. A byte I/O request is therefore independent of the physical device "connected" to the control block which is requesting the I/O. This makes the system "device independent". Filenames are limited to eight alphanumeric characters (the first character must be alpha) which are case insensitive (only capital letters are used; any lowercase letters entered are capitalized). File extensions are up to three characters and obey

2520-401: A prior exposure to BASIC: as potential programmers they are mentally mutilated beyond hope of regeneration", BASIC was one of the few languages that was both high-level enough to be usable by those without training and small enough to fit into the microcomputers of the day, making it the de facto standard programming language on early microcomputers. The first microcomputer version of BASIC

2646-593: A simple password security for files and programs, with separate Read/Execute and full access capabilities. ex: filename/ext.password:drive# . TRSDOS 6.x supports both Owner and User passwords (8 characters max) for disk files. LS-DOS 6.3 uses the space for the User password for its extended dating scheme (past December 31, 1987). Both Model 4 OSes can set various file access levels and permit software write protection for disk files and entire disks. Although MS-DOS owes its heritage most closely to CP/M and thence to TOPS-10 , many of

SECTION 20

#1733084570569

2772-463: A single machine could divide up its processing time among many users, giving them the illusion of having a (slow) computer to themselves. Small programs would return results in a few seconds. This led to increasing interest in a system using time-sharing and a new language specifically for use by non-STEM students. Kemeny wrote the first version of BASIC. The acronym BASIC comes from the name of an unpublished paper by Thomas Kurtz. The new language

2898-406: A smaller introductory version with the initial releases of the machines and a Microsoft-based version introduced as interest in the platforms increased. As new companies entered the field, additional versions were added that subtly changed the BASIC family. The Atari 8-bit computers use the 8 KB Atari BASIC which is not derived from Microsoft BASIC. Sinclair BASIC was introduced in 1980 with

3024-469: A user with administrative privileges. This assignment will be remembered by the same OS on the same PC next time a removable volume is inserted, as long as there are no conflicts, and as long as the removable drive has not been reformatted on another computer (which changes its volume serial number ), and as long as the OS has not been reinstalled on the computer. On Windows XP, mount points may be managed through

3150-511: A version of the MS code, or quickly introduced new models with it. Ohio Scientific's personal computers also joined this trend at that time. By 1978, MS BASIC was a de facto standard and practically every home computer of the 1980s included it in ROM . Upon boot, a BASIC interpreter in direct mode was presented. Commodore Business Machines includes Commodore BASIC , based on Microsoft BASIC. The Apple II and TRS-80 each have two versions of BASIC:

3276-422: A volume packed into a single file. Examples include ISO9660 disc images (CD/DVD images, commonly called "ISOs"), and installer volumes for Mac OS X ( DMGs ). As these volumes are files which reside within another volume, they certainly are not partitions. This example concerns a Windows XP system with two physical hard disks. The first hard disk has two partitions, the second has only one. The first partition of

3402-554: A wide variety of Tiny BASICs with added features or other improvements, with versions from Tom Pittman and Li-Chen Wang becoming particularly well known. Micro-Soft, by this time Microsoft , ported their interpreter for the MOS 6502 , which quickly become one of the most popular microprocessors of the 8-bit era. When new microcomputers began to appear, notably the "1977 trinity" of the TRS-80 , Commodore PET and Apple II , they either included

3528-473: Is a serial number assigned to a disk volume or tape volume . In FAT and NTFS file systems , a volume serial number is a feature used to determine if a disk is present in a drive or not, and to detect if it was exchanged with another one. This identification system was created by Microsoft and IBM during their development of OS/2 . It was introduced in MS-DOS 4.01 in 1988. The volume serial number

3654-407: Is a 32-bit number determined by the date and time on the real-time clock on the current computer at the time of a disk's formatting . Previously, determination by the OS of whether a disk was swapped was done by reading the drive's volume label . However, even at that time the volume label was not required to be unique and was optional. Therefore, many users had not given disks any meaningful name and

3780-545: Is a SYStem or PDS (Partitioned Data Set) file and if a backup has been made, the relative number of the last sector in the file, and the last byte within the last sector (or End Of File). The record also contains the physical area(s) in use by the file, by pointing to the cylinder, relative starting granule, and number of contiguous granules for each extent comprising the file. When a file has more than four extents, additional directory records are used as required with forward and backward pointers linking each record of each file. Thus

3906-559: Is a development of LDOS and has the same capabilities. Hard disk drives (then also known as winchester drives ) required custom driver software supplied by their manufacturers. These drivers permitted any TRSDOS installation to access them with up to eight possible drive partitions , each assigned to drive numbers zero through seven. Actually, a large hard drive could be formatted with more than eight partitions, but TRSDOS can only access eight during any one session. Hard drives could have some partitions formatted under TRSDOS and others under

TRSDOS - Misplaced Pages Continue

4032-424: Is a family of general-purpose , high-level programming languages designed for ease of use. The original version was created by John G. Kemeny and Thomas E. Kurtz at Dartmouth College in 1963. They wanted to enable students in non-scientific fields to use computers. At the time, nearly all computers required writing custom software, which only scientists and mathematicians tended to learn. In addition to

4158-451: Is accomplished by @GET and @PUT SVC requests and is essentially the same as record I/O with a Logical Record Length (LRL) equal to one. (Physical access to a disk storage device is always in units of 256 byte sectors. This is fixed by the TRS-80 disk controller hardware). However, if GET or PUT are used to implement sequential access, then a file can be considered a character I/O device just like

4284-413: Is also the case with NetWare volumes residing inside of a single partition. In short, volumes exist at the logical OS level, and partitions exist at the physical, media specific level. Sometimes there is a one-to-one correspondence, but this is not guaranteed. In Microsoft Windows Server 2008 and onward, the term "volume" is used as a superset that includes "partition" as well. It isn't uncommon to see

4410-408: Is always TRSDOS Ready . All file access requests (whether issued by the user at the console or a program being executed) are satisfied by searching the directory of the first drive specified (taken as drive zero if no drive number is given) and, if the requested file is not found, then searching the next (higher numbered) drive in the system. This continues until the file is found or all the drives in

4536-495: Is constant. For forty-cylinder disks formatted in double density, standard for the drives installed in the TRS-80 Models III and 4, the granule size is six 256-byte sectors, or 1.5 KB. Each track has three granules for 4.5 KB of storage. Each side (surface) of the disk is normally formatted with 40 tracks, yielding 180 KB per side. The Model 4D, with its double-sided drives, yields 360 KB of storage. Whenever additional disk space

4662-577: Is for a subroutine named HELLO_WORLD . This is an introductory program which will print a message to the video display and then exit. Though simple, it demonstrates how an assembler source code is formatted and interacts with the display hardware through TRSDOS. The example uses TRS-80 Model 4 running TRSDOS/LS-DOS 6.x, produced by Tandy/Radio Shack and Logical Systems, with most any assembler sold by Radio Shack or Misosys Inc. (Series I/EDTASM, ALDS, EDAS or MRAS with -GC switch). BASIC BASIC ( Beginners' All-purpose Symbolic Instruction Code )

4788-447: Is minimized by using a hashing technique to reduce the 11-character string formed from the file name and extension to a one byte value. The hash code for each file is stored in a Hash Index Table (HIT) which is the second sector of the directory. Each position in this table corresponds to a specific directory entry record. The hash table, being one sector in length, can index a maximum of 256 directory records or files. The directory itself

4914-407: Is needed for a file (such as extending a file while being written to), an additional granule is allocated. The granule thus becomes the minimum size storage unit. TRSDOS assigns numbers to every sector, every track, and every surface. Surfaces are numbered consecutively starting from zero. Tracks are numbered consecutively starting from zero at the outermost edge of the disk giving the innermost track

5040-571: Is one of the languages that can be accessed by the 4Dos, 4NT, and Take Command enhanced shells. SaxBasic and WWB are also very similar to the Visual Basic line of Basic implementations. The pre-Office 97 macro language for Microsoft Word is known as WordBASIC . Excel 4 and 5 use Visual Basic itself as a macro language. Chipmunk Basic , an old-school interpreter similar to BASICs of the 1970s, is available for Linux , Microsoft Windows and macOS . The ubiquity of BASIC interpreters on personal computers

5166-418: Is sized according to disk capacity by being a maximum of one cylinder (up to 34 sectors). Thus, the larger the disk storage capacity, the larger its directory, and the greater the number of file names that can be stored on the disk. The directory record contains information such as the date the file was last modified, its update and access password codes, its access level, and other attributes such as whether it

TRSDOS - Misplaced Pages Continue

5292-456: Is to be moved outside the volume, the data itself must be relocated, which is a much more expensive operation. In order to better visualize this concept, one might consider the example of a large library. If a non-fiction work is originally classified as having the subject "plants", but then has to be moved to the subject "flora", one does not need to refile the book, whose position on the shelf would be static, but rather, one needs only to replace

5418-487: Is very similar to VBA 6. The Host Explorer terminal emulator uses WWB as a macro language; or more recently the programme and the suite in which it is contained is programmable in an in-house Basic variant known as Hummingbird Basic. The VBScript variant is used for programming web content, Outlook 97, Internet Explorer, and the Windows Script Host. WSH also has a Visual Basic for Applications (VBA) engine installed as

5544-399: Is written for GW-BASIC, but will work in most versions of BASIC with minimal changes: The resulting dialog might resemble: Logical drive In computer data storage, a volume or logical drive is a single accessible storage area with a single file system , typically (though not necessarily) resident on a single partition of a hard disk . Although a volume might be different from

5670-467: The DIR example earlier, drive specifications ( drivespecs ) may be appended to filespecs. These examples assume the selected files have not be made invisible in the disk directory. File access requests issued by applications programs running under TRSDOS work the same way. Under TRSDOS/LS-DOS 6.x, the standard system command interpreter (SYS1/SYS) can be functionally replaced with a custom interpreter by copying

5796-405: The mount command to manipulate mount points for volumes. For example, if a CD-ROM drive containing a text file called 'info.txt' was mounted at ' /mnt/iso9660 ', the text file would be accessible at ' /mnt/iso9660/info.txt '. Files within a volume can generally be moved to any other place within that volume by manipulating the filesystem, without moving the actual data. However, if a file

5922-504: The Apple Macintosh , while yab is a version of yaBasic optimized for BeOS , ZETA and Haiku . These later variations introduced many extensions, such as improved string manipulation and graphics support, access to the file system and additional data types . More important were the facilities for structured programming , including additional control structures and proper subroutines supporting local variables . However, by

6048-477: The HP2000 series in the late 1960s and continuing sales into the 1980s. Many early video games trace their history to one of these versions of BASIC. The emergence of microcomputers in the mid-1970s led to the development of multiple BASIC dialects, including Microsoft BASIC in 1975. Due to the tiny main memory available on these machines, often 4 KB, a variety of Tiny BASIC dialects were also created. BASIC

6174-523: The Nintendo 3DS and Nintendo DSi called Petit Computer allows for programming in a slightly modified version of BASIC with DS button support. A version has also been released for Nintendo Switch , which has also been supplied a version of the Fuze Code System, a BASIC variant first implemented as a custom Raspberry Pi machine. Previously BASIC was made available on consoles as Family BASIC (for

6300-522: The Nintendo Famicom ) and PSX Chipmunk Basic (for the original PlayStation ), while yabasic was ported to the PlayStation 2 and FreeBASIC to the original Xbox . Variants of BASIC are available on graphing and otherwise programmable calculators made by Texas Instruments ( TI-BASIC ), HP ( HP BASIC ), Casio ( Casio BASIC ), and others. QBasic , a version of Microsoft QuickBASIC without

6426-943: The QB64 and FreeBASIC implementations. In 2013 a game written in QBasic and compiled with QB64 for modern computers entitled Black Annex was released on Steam . Blitz Basic , Dark Basic , SdlBasic , Super Game System Basic , PlayBASIC , CoolBasic , AllegroBASIC , ethosBASIC , GLBasic and Basic4GL further filled this demand, right up to the modern RCBasic , NaaLaa , AppGameKit , Monkey 2 and Cerberus-X . In 1991, Microsoft introduced Visual Basic , an evolutionary development of QuickBASIC . It included constructs from that language such as block-structured control statements, parameterized subroutines and optional static typing as well as object-oriented constructs from other languages such as "With" and "For Each". The language retained some compatibility with its predecessors, such as

SECTION 50

#1733084570569

6552-458: The index card . However, to move the book to another library, adjusting index cards alone is insufficient. The entire book must be moved. A volume label is the name given to a specific volume in a filesystem. In the FAT filesystem, the volume label was traditionally restricted to 11 characters (reflecting the 8.3 restrictions, but not divided into name and extension fields) even when long file name

6678-658: The 1959 COBOL specification. These made commands more English-like. For example, the following commands functioned identically: Since TRSDOS does not have the notion of redirection for disk files as UNIX / Linux and MS-DOS do, the APPEND command is somewhat different in concept than the UNIX or MS-DOS notion of appending via output redirection. TRSDOS/LS-DOS 6.x do provide I/O redirection for system devices (keyboard *KI, display screen *DO, printer *PR, serial port *CL), as well as for between devices and disk files. The DEVICE command displays

6804-486: The 1960s, software became a chargeable commodity; until then, it was provided without charge as a service with expensive computers, usually available only to lease. They also made it available to high schools in the Hanover, New Hampshire , area and regionally throughout New England on Teletype Model 33 and Model 35 teleprinter terminals connected to Dartmouth via dial-up phone lines, and they put considerable effort into promoting

6930-561: The BASIC language with a day of events on April 30, 2014. A short documentary film was produced for the event. Minimal versions of BASIC had only integer variables and one- or two-letter variable names, which minimized requirements of limited and expensive memory (RAM). More powerful versions had floating-point arithmetic, and variables could be labelled with names six or more characters long. There were some problems and restrictions in early implementations; for example, Applesoft BASIC allowed variable names to be several characters long, but only

7056-460: The CP/M OS. Each floppy drive in the system would also take up one drive number assignment. The Model 4, with its ability to set up a ramdisk (Memdisk), also required a drive number assignment for this. All versions of TRSDOS use overlays to satisfy most system requests and disk directories are not maintained in memory. This has two implications for system performance. First, upon initial file access

7182-539: The DIR and CAT (Catalog) commands for displaying file data support the usual partial filenames, suffixes, and file dates. Under TRSDOS/LS-DOS 6.x files can be made invisible to the DIR and CAT commands, and can be displayed with the INV parameter (unless any files are password protected and the correct p/w is not given). TRSDOS/LS-DOS 6.3 can dump the video screen to the line printer by pressing CTRL + : . Many versions support

7308-501: The DO was instead indicated by the NEXT I . Likewise, the cryptic IF statement of Fortran, whose syntax matched a particular instruction of the machine on which it was originally written, became the simpler IF I = 5 THEN GOTO 100 . These changes made the language much less idiosyncratic while still having an overall structure and feel similar to the original FORTRAN. The project received

7434-554: The DOS always references the disk directory to obtain information giving the physical mapping of disk space allocated to the file (including its extents, if any). After the initial access this information is maintained in a File Control Block, the memory space for which is supplied by the calling application. Further references do not need to read the disk directory (unless the file is written to and more disk space needs to be allocated). For this reason system performance depends greatly on how close

7560-494: The Dim keyword for declarations, "Gosub"/Return statements and optional line numbers which could be used to locate errors. An important driver for the development of Visual Basic was as the new macro language for Microsoft Excel , a spreadsheet program. To the surprise of many at Microsoft who still initially marketed it as a language for hobbyists, the language came into widespread use for small custom business applications shortly after

7686-652: The Disk Management snap-in for the Microsoft Management Console. This can be most conveniently accessed through "Computer Management" in the "Administrative Tools" section of the Control Panel . More than one drive letter can refer to a single volume, as when using the SUBST command. Warning: removing drive letters or mount-points for a drive may break some programs, as some files may not be accessible under

SECTION 60

#1733084570569

7812-469: The Diskpart command line tool. Windows NT-based OSes do not have a single root directory . As a result, Windows will assign at least one path to each mounted volume, which will take one of two forms: In these two examples, a file called "Track 1.mp3" stored in the root directory of the mounted volume could be referred to as " F:\Track 1.mp3 " or " C:\Music\Track 1.mp3 ", respectively. In order to assign

7938-585: The Model 4 since software needed to access its external memory banks cannot reside in high Z80 RAM memory because that region exists in the banked RAM swap area). These driver routines establish a linkage protocol between the application requesting disk access and the computer's Floppy Disk Controller hardware. TRS-80s use controller chips from the Western Digital series: the WD1791 in the Model 4 non-gate array version, and

8064-564: The Model I supported only single-sided disks with 35 tracks formatted in single density ( sectors are encoded using the frequency modulation technique). Model III TRSDOS (culminating in version 1.3) supported 40-track disks formatted in double density (using modified frequency modulation ). Model Is retrofitted with double density controllers and Models I/III equipped with 80-track drives or double-sided drives could not use TRSDOS; RadioShack sold Logical System's LDOS operating system which could control these types of drives. The Model 4's TRSDOS 6

8190-503: The OS cannot interpret the filesystem stored there. This situation occurs, for example, when Windows NT-based OSes encounter disks with non- Microsoft OS partitions, such as the ext4 filesystem commonly used with Linux . Another example occurs in the Intel world with the "Extended Partition". While these are partitions, they cannot contain a filesystem directly. Instead, "logical drives" (also known as volumes) must be created within them. This

8316-619: The Sinclair ZX80 , and was later extended for the Sinclair ZX81 and the Sinclair ZX Spectrum . The BBC published BBC BASIC , developed by Acorn Computers , incorporates extra structured programming keywords and floating-point features. As the popularity of BASIC grew in this period, computer magazines published complete source code in BASIC for video games, utilities, and other programs. Given BASIC's straightforward nature, it

8442-463: The WD1773 in the Model 4 Gate Array version. When an I/O request is invoked by a higher level SVC, such as a request to READ a file record, the request is translated to that disk primitive (FDC command or status report) needed to satisfy the function request. The linkage protocol is uniform across all disk devices that are connected to the system. This makes the access of files transparent to size or nature of

8568-403: The article prompted Microsoft to develop and release Small Basic ; it also inspired similar projects like Basic-256 and the web based Quite Basic. Dartmouth held a 50th anniversary celebration for BASIC on 1 May 2014. The pedagogical use of BASIC has been followed by other languages, such as Pascal , Java and particularly Python . Dartmouth College celebrated the 50th anniversary of

8694-461: The blink of an eye" even using a "slow" language, as long as large amounts of data were not involved. Many small business owners found they could create their own small, yet useful applications in a few evenings to meet their own specialized needs. Eventually, during the lengthy lifetime of VB3, knowledge of Visual Basic had become a marketable job skill. Microsoft also produced VBScript in 1996 and Visual Basic .NET in 2001. The latter has essentially

8820-460: The boot volume have a mount-point somewhere within the filesystem, represented by a path. Logically, the directory tree stored on the volume is grafted in at the mountpoint. By convention, mount-points will often be placed in a directory called '/mnt', though '/media' and other terms are sometimes used. To use a given path as a mount-point for another volume, a directory (sometimes called a " folder ") must exist there. Unix-like operating systems use

8946-505: The business-focused CP/M computers which soon became widespread in small business environments, Microsoft BASIC ( MBASIC ) was one of the leading applications. In 1978, David Lien published the first edition of The BASIC Handbook: An Encyclopedia of the BASIC Computer Language , documenting keywords across over 78 different computers. By 1981, the second edition documented keywords from over 250 different computers, showcasing

9072-541: The density of the media. Some of these figures (density, sides, granules per track) are written to fields in the Granule Allocation Table which is part of the disk directory. Others (sectors per track, sectors per granule, in addition to the former quantities) are part of the Drive Control Table fields. When the system attempts to open a file on a disk, it uses the @CKDRV SVC to ascertain the availability of

9198-485: The disk device within the scope of the parameters stored in the DCT for that drive. Disk files are supported with two types of access: Record I/O and character I/O. Logical records of from one to 256 bytes in length can be read or written using the @READ or @WRITE SVC requests. Record I/O can be random access (by position SVC requests prior to READ/WRITE) or sequential access using repetitive READs or WRITEs. Character (or byte) I/O

9324-510: The disk directory contains the Granule Allocation Table ( GAT ). The GAT is bit mapped to each granule of space on the drive. Other fields in the GAT contain the PACK NAME, DATE of creation (when the disk was formatted), pack PASSWORD, and data pertaining to the configuration of the drive. When a file is to be opened for access, the system needs to search the directory for its directory record. Search time

9450-504: The disk's physical space, and the FREE command to display a map of a file's physical placement on a drive. The second implication of the overlay-based architecture is that a disk containing TRSDOS system files (file extension /SYS) must always be present in whichever drive is assigned as logical drive number zero. (On the Model 4 this may be the Memdisk, thus freeing physical drive zero be used for

9576-585: The disk, and then logs the disk once it finds it available. This "logging" function will update the DIRCYL field, then update the DBLBIT and MAXCYL fields based on information stored in the GAT. This procedure frees the user from having to manually log a newly inserted disk; he is at liberty to change differently formatted disks in any drive without concern that the system will incorrectly access it. The SVC disk primitives are funneled through common system routines contained in

9702-486: The display with the message: Note that the END statement is optional and has no action in most dialects of BASIC. It was not always included, as is the case in this example. This same program can be modified to print a fixed number of messages using the common FOR...NEXT statement: Most home computers BASIC versions, such as MSX BASIC and GW-BASIC , supported simple data types, loop cycles, and arrays. The following example

9828-401: The drive cannot be accessed for security or safety ( write protection ) purposes. Drives may be set to be write protected by the DOS, also. The primary function of any disk operating system is to provide the user with a facility for managing and accessing files stored on disk storage devices. Since the user must not be burdened with the physical details of the storage devices themselves, it is

9954-463: The driver software installed for each type of disk storage device. The driver for Model III or Model 4 floppy drives is named $ FD and is located in the TRSDOS low memory region. Hard disk drives are supplied with their own driver software, and are usually installed in high memory (main 64K Z80 RAM) above the system HIGH$ pointer, since room in the low memory region is usually insufficient (especially on

10080-449: The emerging field quickly followed suit; Tymshare introduced SUPER BASIC in 1968, CompuServe had a version on the DEC-10 at their launch in 1969, and by the early 1970s BASIC was largely universal on general-purpose mainframe computers . Even IBM eventually joined the club with the introduction of VS-BASIC in 1973. Although time-sharing services with BASIC were successful for a time,

10206-541: The explosive growth of the microcomputer era. When IBM was designing the IBM PC , they followed the paradigm of existing home computers in having a built-in BASIC interpreter. They sourced this from Microsoft – IBM Cassette BASIC – but Microsoft also produced several other versions of BASIC for MS-DOS / PC DOS including IBM Disk BASIC (BASIC D), IBM BASICA (BASIC A), GW-BASIC (a BASICA-compatible version that did not need IBM's ROM) and QBasic , all typically bundled with

10332-467: The file manipulation commands are similar to those of TRSDOS. Some of the following TRSDOS commands exist on disk as distinct program files (DIR/CMD, FORMAT/CMD, BACKUP/CMD) while all others exist as modules condensed into the library files (technically Partitioned Data Sets or PDSs) SYS6/SYS, SYS7/SYS and SYS8/SYS; these include the TRSDOS commands CAT, COPY, LIST, REMOVE, RENAME etc. Some typical TRSDOS utilities: The following Z80 assembler source code

10458-536: The final version 6.0 of the original Visual Basic ended on March 31, 2005, followed by extended support in March 2008. Owing to its persistent remaining popularity, third-party attempts to further support it exist. On February 2, 2017, Microsoft announced that development on VB.NET would no longer be in parallel with that of C#, and on March 11, 2020, it was announced that evolution of the VB.NET language had also concluded. Even so,

10584-406: The first microcomputers in the mid-1970s was the start of explosive growth for BASIC. It had the advantage that it was fairly well known to the young designers and computer hobbyists who took an interest in microcomputers, many of whom had seen BASIC on minis or mainframes. Despite Dijkstra 's famous judgement in 1975, "It is practically impossible to teach good programming to students that have had

10710-613: The first hard disk contains the operating system. Mount points have been left at defaults. In this example, In Linux systems, volumes are usually handled by the Logical Volume Manager or the Enterprise Volume Management System and manipulated using mount(8) . In NT -based versions of Microsoft Windows , volumes are handled by the kernel and managed using the Disk Management MMC snap-in or

10836-489: The first two were significant, thus it was possible to inadvertently write a program with variables "LOSS" and "LOAN", which would be treated as being the same; assigning a value to "LOAN" would silently overwrite the value intended as "LOSS". Keywords could not be used in variables in many early BASICs; "SCORE" would be interpreted as "SC" OR "E", where OR was a keyword. String variables are usually distinguished in many microcomputer dialects by having $ suffixed to their name as

10962-452: The highest number. Where multiple headed drives are in use, the track numbers on a surface are duplicated on each surface with all similarly numbered tracks constituting a cylinder . For a double-sided floppy disk as formatted on a Model 4D, track zero of surface zero and track zero of surface one are grouped together into cylinder zero. Cylinder capacities also have an upper limit of 256 sectors per cylinder or eight granules per cylinder, while

11088-453: The known path. For example, if a program is installed at "D:\Program Files\Some Program", it may expect to find its data files at "D:\Program Files\Some Program\Data". If the logical disk previously called "D:" has its drive letter changed to "E:", "Some Program" won't be able to find its data at "D:\Program Files\Some Program\Data", since the drive letter "D:" no longer represents that volume. In Unix-like operating systems, volumes other than

11214-869: The language was still supported. Many other BASIC dialects have also sprung up since 1990, including the open source QB64 and FreeBASIC , inspired by QBasic, and the Visual Basic-styled RapidQ , HBasic , Basic For Qt and Gambas . Modern commercial incarnations include PureBasic , PowerBASIC , Xojo , Monkey X and True BASIC (the direct successor to Dartmouth BASIC from a company controlled by Kurtz). Several web-based simple BASIC interpreters also now exist, including Microsoft's Small Basic and Google 's wwwBASIC. A number of compilers also exist that convert BASIC into JavaScript . such as NS Basic . Building from earlier efforts such as Mobile Basic , many dialects are now available for smartphones and tablets. On game consoles, an application for

11340-498: The language. How to design and implement a stripped-down version of an interpreter for the BASIC language was covered in articles by Allison in the first three quarterly issues of the People's Computer Company newsletter published in 1975 and implementations with source code published in Dr. Dobb's Journal of Tiny BASIC Calisthenics & Orthodontia: Running Light Without Overbyte . This led to

11466-509: The language. In the following years, as other dialects of BASIC appeared, Kemeny and Kurtz's original BASIC dialect became known as Dartmouth BASIC . New Hampshire recognized the accomplishment in 2019 when it erected a highway historical marker in Hanover describing the creation of "the first user-friendly programming language". The emergence of BASIC took place as part of a wider movement toward time-sharing systems. First conceptualized during

11592-563: The late 1950s, the idea became so dominant in the computer industry by the early 1960s that its proponents were speaking of a future in which users would "buy time on the computer much the same way that the average household buys power and water from utility companies". General Electric, having worked on the Dartmouth project, wrote their own underlying operating system and launched an online time-sharing system known as Mark I. It featured BASIC as one of its primary selling points. Other companies in

11718-403: The latter half of the 1980s, users were increasingly using pre-made applications written by others rather than learning programming themselves; while professional programmers now had a wide range of more advanced languages available on small computers. C and later C++ became the languages of choice for professional "shrink wrap" application development. A niche that BASIC continued to fill

11844-416: The length of its volume label is restricted to 32 characters, and can include lowercase characters and even Unicode . In the exFAT filsystem, the length of its volume label is also restricted to 11 characters, but can include lowercase characters and Unicode. The label command is used to change the label in DOS, Windows, and OS/2. For GUI systems like Windows Explorer , F2 can be pressed while

11970-524: The linker to make EXE files, is present in the Windows NT and DOS- Windows 95 streams of operating systems and can be obtained for more recent releases like Windows 7 which do not have them. Prior to DOS 5, the Basic interpreter was GW-Basic . QuickBasic is part of a series of three languages issued by Microsoft for the home and office power user and small-scale professional development; QuickC and QuickPascal are

12096-685: The machine. In addition they produced the Microsoft BASIC Compiler aimed at professional programmers. Turbo Pascal -publisher Borland published Turbo Basic 1.0 in 1985 (successor versions are still being marketed under the name PowerBASIC ). On Unix-like systems, specialized implementations were created such as XBasic and X11-Basic . XBasic was ported to Microsoft Windows as XBLite , and cross-platform variants such as SmallBasic , yabasic , Bywater BASIC , nuBasic , MyBasic , Logic Basic , Liberty BASIC , and wxBasic emerged. FutureBASIC and Chipmunk Basic meanwhile targeted

12222-437: The new interpreter to the system file SYS13/SYS (which in an unmodified installation is a dummy file). This can be any machine code /CMD program file. This is referred to in the documentation as an "Extended Command Interpreter" or ECI. TRSDOS/LS-DOS 6.x support wildcard characters in filenames, both the single character ? and multicharacter *. TRSDOS (version II) was notable for the inclusion of noise words, similar to

12348-415: The number of sectors in each track of the same media (and in each granule) must always be a constant. Disks are organized as follows: each track is formatted into a specific number of 256-byte sectors with a maximum capacity of 32 sectors per track. Sectors are grouped into blocks called granules which vary in size according to total track capacity of the disk media, though granule size for each disk format

12474-450: The operating system's responsibility to translate file record access requests into specific drive, track, sector, and head parameters that pinpoint the storage location of each record. The system also maintains in Z80 memory within TRSDOS a Drive Control Table that stores the parameters associated with each of the eight logical drives. Disk drive parameters refer to how the total storage space on

12600-580: The original 101 BASIC games converted into the Microsoft dialect and published it from Creative Computing as BASIC Computer Games . This book, and its sequels, provided hundreds of ready-to-go programs that could be easily converted to practically any BASIC-running platform. The book reached the stores in 1978, just as the home computer market was starting off, and it became the first million-selling computer book. Later packages, such as Learn to Program BASIC would also have gaming as an introductory focus. On

12726-446: The other two. For Windows 95 and 98, which do not have QBasic installed by default, they can be copied from the installation disc, which will have a set of directories for old and optional software; other missing commands like Exe2Bin and others are in these same directories. The various Microsoft, Lotus, and Corel office suites and related products are programmable with Visual Basic in one form or another, including LotusScript , which

12852-406: The partition, or when it first recognizes a repartitioning (the creation of a new volume) by a separate disk utility . In contrast to the label, the volume serial number is generally unique and is not normally changed by the user, and thus acts as a more consistent and reliable identifier of when a volume has been changed (as when a disk is removed and another inserted). Disk formatting changes

12978-541: The programming language, Kemeny and Kurtz developed the Dartmouth Time-Sharing System (DTSS), which allowed multiple users to edit and run BASIC programs simultaneously on remote terminals. This general model became popular on minicomputer systems like the PDP-11 and Data General Nova in the late 1960s and early 1970s. Hewlett-Packard produced an entire computer line for this method of operation, introducing

13104-436: The query on all drives. Other commands/utilities such as BACKUP , COPY and PURGE , and drive searches initiated by programs being executed, stop searching at the first drive found to match. If the same filespec exists on multiple drives, then those files on higher-numbered drives will be excluded. File access by partial filenames ( partspecs ), file extensions, and file dates are supported. For example: As with

13230-426: The release of VB version 3.0, which is widely considered the first relatively stable version. Microsoft also spun it off as Visual Basic for Applications and Embedded Visual Basic . While many advanced programmers still scoffed at its use, VB met the needs of small businesses efficiently as by that time, computers running Windows 3.1 had become fast enough that many business-related processes could be completed "in

13356-440: The same power as C# and Java but with syntax that reflects the original Basic language, and also features some cross-platform capability through implementations such as Mono-Basic . The IDE , with its event-driven GUI builder , was also influential on other rapid application development tools, most notably Borland Software 's Delphi for Object Pascal and its own descendants such as Lazarus . Mainstream support for

13482-451: The same rules. File passwords are up to eight characters obeying the same rules (TRSDOS 6 versions up to 6.2 support both owner and user passwords). Entire diskettes can also be assigned master passwords, which may limit user access via the BACKUP and PURGE commands. Under TRSDOS and LDOS the system is never "logged in" to any current drive as with CP/M , PC DOS and MS-DOS . The system prompt

13608-459: The serial number, but relabeling does not. It originated in 1950s in mainframe computer operating systems. In OS/360 line it is human-configurable, has a maximum length of six characters, is in uppercase, must start with a letter, and identifies a volume to the system in unique manner. For example, "SYSRES" is often used for a system residence volume . Operating systems may use the volume serial number as mountpoint name. A volume serial number

13734-497: The system have been searched (but see below for variations on this rule). Drive numbers are specified with a colon : followed immediately with the drive number. The colon is optional unless the drive specification is used as a suffix for a filename. Using the DIR directory command as an example: As seen, the dash character - is used to specify a range of drive numbers. The DIR and CAT (catalog) commands display all file specifications ( filespecs ) matching

13860-431: The system supports (for hard drives with multiple platters of storage media) a maximum of eight heads per drive. The disk's directory cylinder is placed during the format process on the middle-numbered cylinder; thus a standard 40 cylinder disk has its directory installed on cylinder 20. This reduces the average distance (and access time) that the drive's read/write head must move to access the directory. The first sector of

13986-404: The theoretical maximum of 256 files possible on a floppy diskette is realizable only if there is no file fragmentation. When TRSDOS formats a disk, all of the parameters associated with the diskette are predetermined. Thus the number of sectors per track, number of sectors per granule and thus the granules per track, number of sides (surfaces), and number of cylinders are all designated, as well as

14112-452: The third of the default engines along with VBScript, JScript, and the numerous proprietary or open source engines which can be installed like PerlScript , a couple of Rexx-based engines, Python, Ruby, Tcl, Delphi, XLNT, PHP, and others; meaning that the two versions of Basic can be used along with the other mentioned languages, as well as LotusScript, in a WSF file, through the component object model, and other WSH and VBA constructions. VBScript

14238-541: The volume is highlighted, or a right-click on the name will bring up a context menu that allows it to be renamed, either of which is the same process as for renaming a file. Changing the label in Windows will also change the volume creation timestamp to the current date and time for FAT filesystems. NTFS partitions have the System Volume Information directory, whose creation timestamp is set when Windows creates

14364-412: The widespread success predicted earlier was not to be. The emergence of minicomputers during the same period, and especially low-cost microcomputers in the mid-1970s, allowed anyone to purchase and run their own systems rather than buy online time which was typically billed at dollars per minute. BASIC, by its very nature of being small, was naturally suited to porting to the minicomputer market, which

14490-466: Was HP Time-Shared BASIC , which, like the original Dartmouth system, used two computers working together to implement a time-sharing system. The first, a low-end machine in the HP 2100 series, was used to control user input and save and load their programs to tape or disk. The other, a high-end version of the same underlying machine, ran the programs and generated output. For a cost of about $ 100,000, one could own

14616-691: Was a development of Model III LDOS by Logical Systems, Inc. This last was updated in 1987 and released as LS-DOS 6.3. Completely unrelated was a version of TRSDOS by Radio Shack for its TRS-80 Model II professional computer from 1979, also based on the Z80 and equipped with 8-inch disk drives. The later machines in this line, the Models 12, 16 and 6000, used the Z80 as an alternate CPU to its main Motorola 68000 chip and could run this version of TRSDOS for backwards compatibility with older Z80 applications software. Tandy Corporation 's TRS-80 microcomputer did not have

14742-407: Was a simple matter to type in the code from the magazine and execute the program. Different magazines were published featuring programs for specific computers, though some BASIC programs were considered universal and could be used in machines running any variant of BASIC (sometimes with minor adaptations). Many books of type-in programs were also available, and in particular, Ahl published versions of

14868-515: Was as simple as that." Kemeny and Kurtz had made two previous experiments with simplified languages, DARSIMCO (Dartmouth Simplified Code) and DOPE (Dartmouth Oversimplified Programming Experiment) . These did not progress past a single freshman class. New experiments using Fortran and ALGOL followed, but Kurtz concluded these languages were too tricky for what they desired. As Kurtz noted, Fortran had numerous oddly formed commands, notably an "almost impossible-to-memorize convention for specifying

14994-714: Was available for almost any system of the era, and became the de facto programming language for home computer systems that emerged in the late 1970s. These PCs almost always had a BASIC interpreter installed by default, often in the machine's firmware or sometimes on a ROM cartridge. BASIC declined in popularity in the 1990s, as more powerful microcomputers came to market and programming languages with advanced features (such as Pascal and C ) became tenable on such computers. By then, most nontechnical personal computer users relied on pre-written applications rather than writing their own programs. In 1991, Microsoft released Visual Basic , combining an updated version of BASIC with

15120-805: Was co-written by Bill Gates , Paul Allen and Monte Davidoff for their newly formed company, Micro-Soft. This was released by MITS in punch tape format for the Altair 8800 shortly after the machine itself, immediately cementing BASIC as the primary language of early microcomputers. Members of the Homebrew Computer Club began circulating copies of the program, causing Gates to write his Open Letter to Hobbyists , complaining about this early example of software piracy . Partially in response to Gates's letter, and partially to make an even smaller BASIC that would run usefully on 4 KB machines, Bob Albrecht urged Dennis Allison to write their own variation of

15246-542: Was due to their work with RAND Corporation , who had purchased a PDP-6 to run their JOSS language, which was conceptually very similar to BASIC. This led DEC to introduce a smaller, cleaned up version of JOSS known as FOCAL , which they heavily promoted in the late 1960s. However, with timesharing systems widely offering BASIC, and all of their competition in the minicomputer space doing the same, DEC's customers were clamoring for BASIC. After management repeatedly ignored their pleas, David H. Ahl took it upon himself to buy

15372-415: Was emerging at the same time as the time-sharing services. These machines had small main memory , perhaps as little as 4 KB in modern terminology, and lacked high-performance storage like hard drives that make compilers practical. On these systems, BASIC was normally implemented as an interpreter rather than a compiler due to its lower requirement for working memory. A particularly important example

15498-571: Was enabled, stored as an entry within a disk's root directory with a special volume-label attribute bit set, and also copied to an 11-byte field within the Extended BIOS Parameter Block of the disk's boot sector. The label is always stored as uppercase in FAT and VFAT filesystems, and cannot contain special characters that are also disallowed for regular filenames. In the NTFS filesystem,

15624-499: Was for hobbyist video game development , as game creation systems and readily available game engines were still in their infancy. The Atari ST had STOS BASIC while the Amiga had AMOS BASIC for this purpose. Microsoft first exhibited BASIC for game development with DONKEY.BAS for GW-BASIC , and later GORILLA.BAS and NIBBLES.BAS for QuickBASIC . QBasic maintained an active game development community, which helped later spawn

15750-419: Was heavily patterned on FORTRAN II; statements were one-to-a-line, numbers were used to indicate the target of loops and branches, and many of the commands were similar or identical to Fortran. However, the syntax was changed wherever it could be improved. For instance, the difficult to remember DO loop was replaced by the much easier to remember FOR I = 1 TO 10 STEP 2 , and the line number used in

15876-437: Was such that textbooks once included simple "Try It In BASIC" exercises that encouraged students to experiment with mathematical and computational concepts on classroom or home computers. Popular computer magazines of the day typically included type-in programs . Futurist and sci-fi writer David Brin mourned the loss of ubiquitous BASIC in a 2006 Salon article as have others who first used computers during this era. In turn,

#568431