Tiny BASIC

File:Altair BASIC Paper Tape.jpg

The earliest microcomputers, like the MITS Altair 8800, generally had no built-in input/output (I/O) beyond front-panel switches and LED lamps. Useful work generally required the addition of an I/O expansion card and the use of some form of terminal. At the time, video-based terminals were very expensive, costing much more than the computer, so many users turned to mechanical devices like the Teletype Model 33. The Model 33, like most teleprinters of the era, included a tape punch system intended to allow operators to pre-record their messages and then play them at "high speed", faster than most individuals could type the message live. For the early microcomputers, this provided a convenient computer data storage format, allowing the users to write programs to paper tape and distribute them to other users.{{cite web|first=Don|last=Lancaster|url=https://www.tinaja.com/ebooks/tvtcb.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.tinaja.com/ebooks/tvtcb.pdf |archive-date=2022-10-09 |url-status=live|title=TV Typewriter Cookbook|date=1976|pages=210–211}}

The Homebrew Computer Club met for the first time in March 1975, and its members soon used the meetings to swap software on punched tape. At the June meeting, a tape containing a pre-release version of Altair BASIC disappeared. The tape was given to Steve Dompier, who passed it on to Dan Sokol, who had access to a high-speed tape punch. At the next meeting, 50 copies of Altair BASIC on paper tape appeared in a cardboard box.{{sfn|Manes|Andrews|1994|p=81}} When Ed Roberts, founder of MITS, learned of this, he stated "Anyone who is using a stolen copy of MITS BASIC should identify himself for what he is, a thief."{{cite journal|title=Letter from the President |journal=Computer Notes |last=Roberts |first=H. Edward |volume=1 |issue=5 |pages=3–4 |publisher=MITS |location=Albuquerque NM. |date=October 1975 |url=http://startup.nmnaturalhistory.org/gallery/notesViewer.php?ii=75_10&p=3 |url-status=dead |archive-url=https://web.archive.org/web/20120323162008/http://startup.nmnaturalhistory.org/gallery/notesViewer.php?ii=75_10&p=3 |archive-date=March 23, 2012}} Bill Gates made this more formal, writing "An Open Letter to Hobbyists", complaining that "As the majority of hobbyists must be aware, most of you steal your software."{{sfn|Manes|Andrews1994|p=91}}

The complaint was not well received. Among the many responses, Bob Albrecht, another Homebrew member and founder of the People's Computer Company (PCC), felt the best response would be to produce their own BASIC that was completely free to use by anyone. He approached Dennis Allison, a member of the Computer Science faculty at Stanford University, to write a specification for a version of BASIC that would fit in 2 to 3 kilobytes of memory.{{efn|At the time, the most common memory size for the 8080 was 4 KB, which cost hundreds of dollars.}} To aid porting, the design was based on an intermediate language (IL), an interpreter for the interpreter, which meant only a small portion of the total code had to be ported.

Allison's initial design was published in the September 1975 edition of the PCC newsletter, along with an Intel 8080 version of the IL interpreter. The article called on programmers to implement the design on their computer and send the resulting assembly language version back to the PCC. They stated their plans to publish three special newsletters containing these user-submitted versions, along with bug fixes, programs written in the new BASIC, and suggestions and enhancements. The concept gained further notice when it was republished in the January 1976 edition of the ACM Special Interest Group on Programming Languages.{{Cite journal|last=Allison |first=Dennis |title=Design notes for TINY BASIC |journal=SIGPLAN Notices |volume=11 |issue=7 |pages=25–33 |publisher=ACM |date=July 1976 |doi=10.1145/987491.987494 |s2cid=18819472 |doi-access=free }} Submissions poured in. Among the notable early versions was Tiny BASIC Extended by Dick Whipple and John Arnold which ran in 3K of RAM, added FOR...NXT loops, and allowed a single numeric array. They avoided the use of the IL and wrote it directly in machine code, using octal.

The first of the three planned newsletters, with the title "Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Running Light Without Overbyte", was published in January 1976.{{Cite journal |journal=Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Running Light Without Overbyte |title=TB Code Sheet |volume=1 |issue=1 |date=December 1975 |url=https://archive.org/details/dr_dobbs_journal_vol_01/page/n1/mode/2up}} It starts with a note from Albrecht, under the penname "the dragon", suggesting that three editions would not be enough, and asked the readers if they would like to see it continue. It also reprinted the original article on Tiny BASIC from PCC, included the complete listing of Extended TB, and included a number of small BASIC programs including tips-and-tricks from Allison.{{sfn|Dobbs|1976|p=5}} Response to the first issue was so impressive that the introduction to the second issue stated they had already decided to continue publishing the new newsletter under the simplified name Dr. Dobb's Journal. Over the next several issues, additional versions of the language were published, and similar articles began appearing in other magazines like Interface Age.

File:Copyleft All Wrongs Reserved.png

By the middle of 1976, Tiny BASIC interpreters were available for the Intel 8080, the Motorola 6800 and MOS Technology 6502 processors. This was a forerunner of the free software community's collaborative development before the internet allowed easy transfer of files, and was an example of a free software project before the free software movement.{{cite web|url=http://www.ibm.com/developerworks/library/os-openhardware/|title=Open hardware: How and why it works|website=IBM |quote=The open software movement was founded by Dennis Allison in his release of Tiny BASIC in 1975}} Computer hobbyists would exchange paper tapes, cassettes or even retype the files from the printed listings.{{Cite journal| last = Warren | first = Jim C. | author-link =Jim Warren (computer specialist)| title = Correspondence | journal = SIGPLAN Notices | volume = 11 | issue = 7 | pages =1–2 | publisher = ACM | issn = 0362-1340 |date=July 1976}}

Jim Warren, editor of Dr. Dobb's, wrote in the July 1976 ACM Programming Language newsletter about the motivations and methods of this successful project. He started with this: "There is a viable alternative to the problems raised by Bill Gates in his irate letter to computer hobbyists concerning 'ripping off' software. When software is free, or so inexpensive that it's easier to pay for it than to duplicate it, then it won't be 'stolen'." The Bill Gates letter was written to make software into products. The alternative method was to have an experienced professional do the overall design and then outline an implementation strategy. Knowledgeable amateurs would implement the design for a variety of computer systems. Warren predicted this strategy would be continued and expanded.

The May 1976 issue of Dr. Dobbs has Li-Chen Wang's Palo Alto Tiny BASIC for the 8080. The listing begins with the title, author's name, and date but it also has "@COPYLEFT ALL WRONGS RESERVED".{{Cite journal|last=Wang |first=Li-Chen |author-link=Li-Chen Wang |title=Palo Alto Tiny BASIC |journal=Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Running Light Without Overbyte |volume=1 |issue=5 |pages=12–25 |date=May 1976}} Source code begins with the following six lines.

TINY BASIC FOR INTEL 8080

VERSION 1.0
BY LI-CHEN WANG
10 JUNE, 1976
@COPYLEFT
ALL WRONGS RESERVED

;*********************************

;
;    TINY BASIC FOR INTEL 8080
;          VERSION 2.0
;        BY LI-CHEN WANG
;     MODIFIED AND TRANSLATED
;       TO INTEL MNEMONICS
;        BY ROGER RAUSKOLB
;         10 OCTOBER,1976
;           @COPYLEFT
;      ALL WRONGS RESERVED
;
;*********************************

{{See also|BASIC interpreter#Compilers vs. interpreters|l1=BASIC interpreters}}

Tiny BASIC was designed to use as little memory as possible, and this is reflected in the paucity of features as well as details of its interpreter system. Early microcomputers lacked the RAM and secondary storage for a BASIC compiler, which was more typical of timesharing systems.

Like most BASICs of the era, Tiny Basic was interactive with the user typing statements into a command line. As microcomputers of the era were often used with teletype machines or "dumb" terminals, direct editing of existing text was not possible and the editor instead used takeout characters, often the backslash, to indicate where the user backed up to edit existing text.

If the user typed a statement into the command line the system examined it to see if it started with a number. If it did not, the line was immediately parsed and operated on, potentially generating output via {{code|PRINT}}. This was known as "direct mode".

If the line was entered with a leading number, the number was converted from decimal format, like "50", and converted to a 8-bit value, in this case, {{code|$32}} hexadecimal. This number was used as an index into an array-like storage area where the rest of the line was stored in exactly the format it was typed. When the user typed {{code|LIST}} into the command line the system would loop over the array, convert the line number back to decimal format, and then print out the rest of the text in the line.

When a program was present in memory and the user types in the {{code|RUN}} command, the system enters "indirect mode". In this mode, a pointer is set to point to the first line of the program, for instance, 10 ({{mono|{{#invoke:BaseConvert|10to16|10|width=2|prefix=$|suffix={{sub|hex}}}}}}). The original text for that line is then retrieved from the store and run as if the user had just typed it in direct mode. The pointer then advances to the next line and the process continues.

The grammar is listed below in Backus–Naur form, almost exactly as it was specified in the Design Note.{{cite magazine |title=Build Your Own BASIC |first=Dennis |last=Allison |magazine=Dr. Dobb's Journal |volume=1 |number=1 |date=1976 |url=https://archive.org/details/dr_dobbs_journal_vol_01/page/n9 |page=9}} In the listing, an asterisk ("*") denotes zero or more of the object to its left{{snd}} except for the first asterisk in the definition of "term", which is the multiplication operator; parentheses group objects; and an epsilon ("ε") signifies the empty string. As is common in computer language grammar notation, the vertical bar ("|") distinguishes alternatives, as does their being listed on separate lines. The symbol "CR" denotes a carriage return (usually generated by a keyboard's "Enter" key). A BREAK from the console will interrupt execution of the program.

line ::= number statement CR | statement CR

statement ::= PRINT expr-list

IF expression relop expression THEN statement

GOTO expression

INPUT var-list

LET var = expression

GOSUB expression

RETURN

CLEAR

LIST

RUN

END

expr-list ::= (string|expression) (, (string|expression) )*

var-list ::= var (, var)*

expression ::= (+|-|ε) term ((+|-) term)*

term ::= factor ((*|/) factor)*

factor ::= var | number | (expression)

var ::= A | B | C ... | Y | Z

number ::= digit digit*

digit ::= 0 | 1 | 2 | 3 | ... | 8 | 9

relop ::= < (>|=|ε) | > (<|=|ε) | =

string ::= " ( |!|#|$ ... -|.|/|digit|: ... @|A|B|C ... |X|Y|Z)* "

Note that string wasn't defined in the Design Note.

This syntax, as simple as it was, added one innovation: {{code|GOTO}} and {{code|GOSUB}} could take an expression rather than just a line number, providing an assigned GOTO{{cite magazine |title=Quick Reference Guide for Tiny BASIC |first=Dennis |last=Allison |magazine=Dr. Dobb's Journal |volume=1 |number=1 |date=1976 |url=https://archive.org/details/dr_dobbs_journal_vol_01/page/n6 |page=6}} rather than the switch statement of the {{code|GOTO/GOSUB ... OF ...}}, a structure then supported in HP Time-Shared BASIC and predating {{code|ON ... GOTO}}. The syntax allowing {{code|IF-THEN statement}} (as opposed to just a line number to branch to) was not yet supported in Dartmouth BASIC at this time but had been introduced by Digital{{cite book|url=https://archive.org/details/bitsavers_decpdp11rsSICPLUSLangManOct72_10455777|title=BASIC-PLUS Language Manual|publisher=Digital Equipment Corporation|year=1972|location=Maynard, Massachusetts|type=PDF|pages=3–13|ref=CITEREFPLUS1972}} and copied by Microsoft.

The Design Note specified a virtual machine, in which the Tiny BASIC interpreter is itself run on a virtual machine interpreter. The designer's idea to use an application virtual machine goes back to Val Schorre (with META II, 1964) and Glennie (Syntax Machine). The choice of a virtual machine approach economized on memory space and implementation effort, although the BASIC programs run thereon were executed somewhat slowly.{{cite journal|last1=Allen|first1=Dennis|title=TINY BASIC|journal=People's Computer Company|volume= 4|issue= 3}}

Dialects that used the virtual machine included Tiny BASIC Extended, Tom Pittman's Tiny BASIC{{cite web|last1=Veit|first1=Holger|title=Tom Pittman's 6800 tiny BASIC|url=http://www.ittybittycomputers.com/IttyBitty/TinyBasic/TB_6800.asm|access-date=2 May 2017}} and NIBL. Other dialects such as Denver Tiny BASIC (DTB) and Palo Alto Tiny BASIC were direct interpreters. Some programmers, such as Fred Greeb with DTB, treated the IL (Interpretive Language) program as pseudocode for the algorithm to implement in assembly language; Denver Tiny BASIC did not use a virtual machine, but it did closely follow the IL program.

This is a representative excerpt from the 120-line IL program:

S1: TST S3,'GO' ;GOTO OR GOSUB?

TST S2,'TO' ;YES...TO, OR...SUB

CALL EXPR ;GET LABEL

DONE ;ERROR IF CR NOT NEXT

XFER ;SET UP AND JUMP

S3: TST S8,'PRINT' ;PRINT.

A common pattern in the program is to test for a keyword or part of a keyword, then act on that information. Each test is an assertion as to what is next in the line buffer. If the assertion fails, control jumps to a subsequent label (usually looking for a new keyword or token). Here the system advances its buffer cursor over any spaces and tests for {{mono|GO}} and if it fails to find it then jumps to line {{mono|S3}}. If it finds it, execution continues with the next IL command. In this case, the system next tests for {{mono|TO}}, skipping to line {{mono|S2}} if it fails (a test for {{mono|SUB}}, to see if this is instead a {{mono|GOSUB}} command). If it passes, control continues; in this case, calling an IL subroutine that starts at label {{mono|EXPR}}, which parses an expression. In Tiny BASIC, {{code|GOTO X*10+100}} (a computed GO TO) is as legal as {{code|GOTO 100}} and is the alternative to the ON-GOTO of larger BASIC implementations. The subroutine {{mono|EXPR}} pushes the result of the expression onto the arithmetic stack (in this case, the line number). {{mono|DONE}} verifies no other text follows the expression and gives an error if it does. {{mono|XFER}} pops the number from the stack and transfers execution (GOes TO) the corresponding line number, if it exists.

The following table gives a partial list of the 32 commands of the virtual machine in which the first Tiny BASIC interpreter was written.Dr. Dobb's Journal, Volume 1, Number 1, 1976, p. 12.

; {{mono|TST lbl, string}}

: If string matches the BASIC line, advance cursor over {{mono|string}} and execute the next IL instruction; if the test fails, execute the IL instruction at the label lbl

; {{mono|CALL lbl}} : Execute the IL subroutine starting at {{mono|lbl}}; save the IL address following the CALL on the control stack

; {{mono|DONE}} : Report a syntax error if after deleting leading blanks the cursor is not positioned to reach a carriage return

; {{mono|XFER}} : Test value at the top of the AE stack to be within range. If not, report an error. If so, attempt to position cursor at that line. If it exists, begin interpretation there; if not, report an error.

; {{mono|JUMP lbl}} : Continue execution of the IL at the label specified

; {{mono|RTN}} : Return to the IL location specified at the top of the control stack

; {{mono|PRS}} : Print characters from the BASIC text up to but not including the closing quotation mark

; {{mono|PRN}} : Print number obtained by popping the top of the expression stack

; {{mono|SPC}} : Insert spaces to move the print head to next zone

; {{mono|NLINE}} : Output a CRLFThe CRLF there symbolizes a carriage return followed by a line feed. to the printer

Tom Pittman, discussing the IL, says: "The TINY BASIC interpreter was designed by Dennis Allison as a recursive descent parser. Some of the elegant simplicity of this design was lost in the addition of syntactical sugar to the language but the basic form remains. The IL is especially suited to Recursive Descent parsing of TINY BASIC because of the general recursive nature of its procedures and the simplicity of the TINY BASIC tokens. The IL language is effectively optimized for the interpretation of TINY. Experience has shown that the difficulty of adding new features to the language is all out of proportion with the nature of the features. Usually it is necessary to add additional machine language subroutines to support the new features. Often the difficulty outweighs the advantages."{{cite web| url=http://www.ittybittycomputers.com/IttyBitty/TinyBasic/TBEK.txt | title=Tiny BASIC Experimenter's Kit | last=Pittman | first=Tom | access-date=August 9, 2020}}

Defining Tiny BASIC for the Homebrew Computer Club, Pittman wrote, "Tiny BASIC is a proper subset of Dartmouth BASIC, consisting of the following statement types only: LET, PRINT, INPUT, IF, GOTO, GOSUB, RETURN, END, CLEAR, LIST, RUN. Arithmetic is in 16-bit integers only with the operators + - * / and nested parentheses. There are only the 26 single letter variable names A, B, ...Z, and no functions. There are no strings or arrays... Tiny BASIC specifies line numbers less than 256."{{cite web|url=https://archive.computerhistory.org/resources/access/text/2015/02/102740021-05-14-acc.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://archive.computerhistory.org/resources/access/text/2015/02/102740021-05-14-acc.pdf |archive-date=2022-10-09 |url-status=live| title= TINY BASIC 6800 |access-date=13 Aug 2020}} He then went on to describe his implementation: "This language has been augmented to include the functions RND, USR, and PEEK and POKE, giving the user access to all his system components in the 6800 from the BASIC program."

Many implementers brought their own experiences with HP Time-Shared BASIC or DEC BASIC-PLUS to their designs and relaxed the formal Tiny BASIC language specification. Of the seven prominent implementations published by 1977:

• All added some sort of random number function, typically {{code|RND()}}. Though not included in the specification, a newsletter article prior to the Design Note for Tiny BASIC requested only this function.
• All enabled {{code|LET}} to be optional and most let expressions in assignment statements contain relational operators.
• All but 6800TB supported statement delimiters in lines, typically {{code|:}} although TBX used {{code|$}} and PATB used {{code|;}}.
• In {{code|IF}} statements, all but MINOL removed the need for expressions to contain relational operators (e.g., {{code|2=basic|1=IF X THEN LET Y=X}} was valid). Implementations removed {{code|THEN}} altogether or made it optional or supported it only for implied {{code|GOTO}}. None supported {{code|ELSE}} clauses.
• Many modified {{code|PRINT}} to support print zones, using {{code|,}} to go to the next zone and {{code|;}} to not advance the cursor.
• All but 6800TB and DTB added {{code|NEW}}.
• All but 6800TB and MINOL added a function to return memory size: TBX had {{code|SZE}}, DTB and PATB had {{code|SIZE}}, L1B had {{code|MEM}}, and NIBL had {{code|TOP}}.
• Four implementations added arrays, whether a single, undimensioned array in PATB and L1B or {{code|DIM}}ensionable arrays in TBX and DTB.
• Four implementations added the {{code|REM}}ark statement.
• Four implementations added the {{code|FOR}} loop: PATB, NIBL, and L1B offered {{code|FOR-TO-STEP/NEXT}}, while TBX did not support {{code|STEP}} and used the keyword {{code|NXT}} to end a loop.
• Only NIBL had any nod towards structured programming, with {{code|DO/UNTIL}}, despite Allison's lament in Issue 2 about problems with BASIC.

As an alternative to tokenization, to save RAM, TBX,{{Cite journal |journal=Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Running Light Without Overbyte |title=Tiny BASIC Extended |volume=1 |issue=2 |date=February 1976}} DTB,{{Cite journal |journal=Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Running Light Without Overbyte |title=Denver Tiny BASIC |volume=1 |issue=3 |date=March 1976}} and MINOL{{Cite journal |journal=Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Running Light Without Overbyte |title=MINOL |volume=1 |issue=4 |date=April 1976}} truncated keywords: {{code|PR}} for {{code|PRINT}}, {{code|IN}} for {{code|INPUT}}, {{code|RET}} for {{code|RETURN}}. The full, traditional keywords were not accepted. In contrast, PATB allowed accepted traditional keywords but also allowed any keyword to be abbreviated to its minimal unique string, with a trailing period. For instance, {{code|PRINT}} could be typed {{code|P.}}, although {{code|PR.}} and other variations also worked. This system was retained in Level I BASIC for the TRS-80, which used PATB, and was also later found in Atari BASIC and the BASIC of various Sharp Pocket Computers.{{cite magazine |first=Roger |last=Rauskolb |title=Dr. Wang's Palo Alto Tiny BASIC |magazine=Interface Age |date=December 1976 |pages=92–108 |url=http://www.jk-quantized.com/experiments/8080Emulator/TinyBASIC-2.0.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.jk-quantized.com/experiments/8080Emulator/TinyBASIC-2.0.pdf |archive-date=2022-10-09 |url-status=live}}

The most prominent dialects of Tiny BASIC were the original Design Note, Tiny BASIC Extended, Palo Alto Tiny BASIC, and 6800 Tiny BASIC. However, many other versions of Tiny BASIC existed.

Tiny BASIC was first published in a newsletter offshoot of the People's Computer Company, a newsletter which became Dr. Dobb's Journal, a long-lived computing magazine. About ten versions were published in the magazine.

TBX was also known as Texas Tiny BASIC.{{Cite journal |title=Texas Tiny BASIC (TBX) Marries TV-Cassette Operating System (TVCOS) |journal=Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Running Light Without Overbyte |volume=1 |issue=5 |pages=28–31 |date=May 1976}}

Both SCELBAL{{cite magazine |magazine=Dr. Dobb's Journal |date=February 1976 |title=SCELBAL – A Higher Level Language for 8008/8080 Systems |first1=Mark |last1=Arnold |first2=Nat |last2=Wadsworth |url=https://archive.org/details/dr_dobbs_journal_vol_01/page/n31/mode/2up |pages=30–53}} and 6800 Tiny BASIC were announced in the magazine but did not publish their source code.

{{Infobox programming language

| name = Palo Alto Tiny BASIC

| logo =

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| developer = Li Chen Wang

| released = 1976

| latest release version =

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| license = Public domain

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| dialects = 3K Control Basic

| influenced by = Tiny BASIC Design Note, Tiny BASIC Extended

| influenced = Astro BASIC, Level I BASIC, Sharp PC-1211 BASIC

}}

One of the most popular of the many versions of Tiny BASIC was Palo Alto Tiny BASIC, or PATB for short, by Li-Chen Wang. PATB first appeared in the May 1976 edition of Dr. Dobbs, written in a custom assembly language with non-standard mnemonics. This led to further ports that worked with conventional assemblers on the 8080. The first version of the interpreter occupied 1.77 kilobytes of memory and assumed the use of a Teletype Machine (TTY) for user input/output. An erratum to the original article appeared in the June/July issue of Dr. Dobb's (Vol. 1, No 6). This article also included information on adding additional I/O devices, using code for the VDM video display by Processor Technology as an example.

Wang was one of the first to use the word copyleft.

In Palo Alto Tiny BASIC's distribution notice, he had written "@COPYLEFT ALL WRONGS RESERVED".{{Cite journal|last=Wang|first=Li-Chen|author-link=Li-Chen Wang|date=May 1976|title=Palo Alto Tiny BASIC|journal=Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Running Light Without Overbyte|volume=1|issue=5|pages=12–25}} (NB. Source code begins with the following six lines. "TINY BASIC FOR INTEL 8080; VERSION 1.0; BY LI-CHEN WANG; 10 JUNE, 1976; @COPYLEFT; ALL WRONGS RESERVED". The June date in the May issue is correct. The magazine was behind schedule, the June and July issues were combined to catch up.) Tiny BASIC was not distributed under any formal form of copyleft distribution terms, but was presented in a context where source code was being shared and modified. In fact, Wang had earlier contributed edits to Tiny BASIC Extended before writing his own interpreter. He encouraged others to adapt his source code and publish their adaptions, as with Roger Rauskolb's version of PATB published in Interface Age. He also published a third version in PCC's Reference Book of Personal and Home Computing.{{cite book |last1=McCabe |first1=Dwight [editor] |title=PCC's Reference Book of Personal and Home Computing |date=July 1, 1977 |publisher=People's Computer Company |location=Menlo Park, CA |isbn=0-918790-02-6 |pages=248 |edition=1st}}

One of the most notable changes in PATB is the addition of the FOR...NEXT loop. In the original TB, loops could only be implemented using {{code|IF}} and {{code|GOTO}}. As in Microsoft BASIC, the upper and lower bounds of the loop were set on loop entry, and did not change during the loop, so if one of the bounds was based on a variable expression; changing the variable did not change the bound. The {{code|STEP}} modifier was optional, as in MS.

Another significant change was the ability to place several statements on a single line. For reasons not explained, PATB used the semicolon {{code|;}} to separate statements, rather than the already common colon {{code|:}}.

Other changes include the addition of a single numeric array, with the variable name {{code|@}}, {{code|STOP}} in addition to {{code|END}}, and the use of {{code|#}} for not-equals in comparisons, as opposed to {{code|<>}}.{{efn|Hash was also used for not-equals in HP Time-Shared BASIC.}}

PATB used words for error messages instead of numbers. To reduce the amount of memory required, there were only three messages and they consisted of single words. The system would respond with {{code|WHAT?}} for syntax errors, {{code|HOW?}} for run-time errors like GOTOs to a line that didn't exist or numeric overflows, and {{code|SORRY}} for out-of-memory problems.

Wang also wrote a STARTREK program in his Tiny BASIC that appeared in the July 1976 issue of the People's Computer Company Newsletter.{{cite web|title=People's Computer Company|url=https://archive.computerhistory.org/resources/access/text/2017/09/102661095/102661095-05-v5-n1-acc.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://archive.computerhistory.org/resources/access/text/2017/09/102661095/102661095-05-v5-n1-acc.pdf |archive-date=2022-10-09 |url-status=live|access-date=25 December 2019}}{{cite web|last=Turnbull|first=Pete|title=Startrek.asc|url=http://www.dunnington.info/public/startrek/startrek.asc|access-date=25 December 2019|archive-date=24 February 2021|archive-url=https://web.archive.org/web/20210224135453/http://www.dunnington.info/public/startrek/startrek.asc|url-status=dead}}

He later adapted the language into 3K Control Basic for Cromemco, adding variable names of the form letter-digit (e.g., A0 to Z9), logic functions (AND(), OR(), XOR()), a CALL command to execute machine language routines, more PRINT-formatting options, and others (GET() and PUT() instead of PEEK and POKE; I/O port functions).{{cite web|title=3K Control Basic Instruction Manual |url=http://www.dunnington.u-net.com/public/Cromemco/Cromemco%203K%20Basic%20Instruction%20Manual.PDF |publisher=Cromemco |access-date=2013-02-18 |url-status=dead |archive-url=https://web.archive.org/web/20131222220843/http://www.dunnington.u-net.com/public/Cromemco/Cromemco%203K%20Basic%20Instruction%20Manual.PDF |archive-date=2013-12-22 }}

Palo Alto Tiny BASIC was adapted for many other implementations, including Level I BASIC (1977), BASIC for the Sharp PC-1211 pocket computer (1980), and Astro BASIC (1982, by Jamie Fenton).{{cite book |last1=Ainsworth |first1=Dick |title=Astro BASIC |date=1982 |publisher=Astrocade, Inc. |page=3}}

Written by a junior in high school, MINOL was the only implementation that didn't support the full Design Note, lacking operator precedence, having only three relational operators (<, =, #), omitting {{code|GOSUB}} and {{code|RETURN}}.

It only supported unsigned 8-bit precision (in contrast to signed 16-bit precision for every other implementation) and line numbers from 0 to 254.

No spaces were permitted except in strings; {{code|!}} returns a random number, {{code|$}} before an expression loads a string at that address; {{code|OS}} returns to operating system. Memory was addressable as if it were a two-dimensioned array of high and low bytes (e.g., "(0,0)" to "(255,255)"); {{code|CALL}} executes a machine language subroutine.

Many dialects appeared in various other publications.

File:FloppyRom_Magazine.jpg

Inspired by PCC's call for Tiny BASICs, Robert Uiterwyk wrote MICRO BASIC 1.3 for the SWTPC 6800 system), which SWTPC published in the June 1976 issue of the SWTPC newsletter. Uiterwyk had handwritten the language on a legal tablet. He later expanded the language to 4K, adding support for floating point; this implementation was unique among BASIC interpreters by using Binary Coded Decimal to 9 digits of precision, with a range up to 10⁹⁹, and by being published for free as a "Floppy ROM" magazine insert. An 8K version added string variables and trigonometry functions. Both the 4K and 8K versions were sold by SWTPC. In January, 1978, Uiterwyk sold the rights of the source code to Motorola.{{Cite web | url=https://deramp.com/swtpc.com/BASIC_2/Uiterwyk.htm | title = Robert Uiterwyk's BASIC}}{{Cite web | url=https://deramp.com/swtpc.com/NewsLetter1/MicroBasic.htm | title = Robert Uiterwyk's Micro Basic}}

Thomas F. Waitman wrote a Tiny BASIC in 1976 for the Hewlett-Packard HP-2640 and HP-2645 terminals (which used the Intel 8008 and 8080 processors), which was published in the Hewlett-Packard Journal.

Published in the December 1976 issue of Interface Age was LLL (Lawrence Livermore Laboratory) BASIC, the first draft of which was developed by Steve Leininger from Allison's specification before Leininger left National Semiconductor for Tandy Corporation. The final interpreter was developed by John Dickenson, Jerry Barber, and John Teeter at the University of Idaho on a contract with LLL. Taking 5K, it included a floating-point package, developed by David Mead, Hal Brand, and Frank Olken. The program was placed into the public domain by LLL, which developed the system under the auspices of the

U.S. Energy Research and Development Administration.{{cite web | url=http://www.bitsavers.org/pdf/interfaceAge/197612/110-124.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.bitsavers.org/pdf/interfaceAge/197612/110-124.pdf |archive-date=2022-10-09 |url-status=live | title=Part 1 Of LLL 8080 BASIC Interpreter}}

Altair BASIC, 4K BASIC, could run within a 4 KB RAM machine, leaving only about 790 bytes free for program code.{{cite web |url=http://www.virtualaltair.com/virtualaltair.com/vac_Altair_BASIC.asp |title=4 Altair Language Systems |website=Altair BASIC}}{{cite book |url=http://www.virtualaltair.com/virtualaltair.com/PDF/AltairBasic_1275.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.virtualaltair.com/virtualaltair.com/PDF/AltairBasic_1275.pdf |archive-date=2022-10-09 |url-status=live |title=Altair BASIC |date=25 August 1975 |publisher=MITS}} The Tiny BASIC initiative started in response to the $150 charge for Altair 4K BASIC.

In 1975, Steve Wozniak joined the newly formed Homebrew Computer Club, which had fellow members Li-Chen Wang (Palo Alto Tiny BASIC) and Tom Pittman (6800 Tiny BASIC). Wozniak concluded that his machine would have to have a BASIC of its own, which would, hopefully, be the first for the MOS Technology 6502 processor. As the language needed 4 KB RAM, he made that the minimum memory for the design.{{cite web

|first=Steven |last=Wozniak

|title=How Steve Wozniak Wrote BASIC for the Original Apple From Scratch

|website=Gizmodo

|url=https://gizmodo.com/how-steve-wozniak-wrote-basic-for-the-original-apple-fr-1570573636

|date=1 May 2014

}} Integer BASIC was originally published on Compact Cassette in 1976.

In 1977, Radio Shack (as it was known then) released their first computer, the TRS-80, a Z80 system with Level I BASIC in a 4 KB ROM. Tandy-employee Steve Leininger had written the first draft of the NIBL (National Industrial Basic Language) interpreter for the SC/MP while employed at National Semiconductor.

Unable to take that source code with him, he adapted Li-Chen Wang's Palo Alto Tiny BASIC for the original prototype of the TRS-80 Model I. He extensively revised the interpreter, adding floating-point support, simple black-and-white graphics, and {{code|READ/DATA/RESTORE}} statements.{{cite book |last1=Welsh |first1=David |last2=Welsh |first2=Theresa |title=Priming the Pump: How TRS-80 Enthusiasts Helped Spark the PC Revolution |date=2007 |page=7}}

Originally developed in 1979, Sinclair 4K BASIC, written by John Grant, used as its language definition the 1978 American National Standards Institute (ANSI) Minimal BASIC standard, but was itself an incomplete 4 KB implementation with integer arithmetic only.{{cite web|title=ZX80 – 8K BASIC ROM UPGRADE|url=http://www.fruitcake.plus.com/Sinclair/ZX80/ROMUpgrade/ZX80_ROMUpgrade.htm}}

Tiny BASIC implementations have been adapted for processor control and for microcontrollers such as the Arduino:

• Stephen A. Ness wrote XYBASIC for the Mark Williams Company in 1977, a 4K integer implementation. The language was often used for process control applications.{{cite web|last1=Ness|first1=Stephen|title=XYBASIC|url=http://www.nesssoftware.com/home/mwc/XYBASIC.php|website=Ness Software|access-date=4 August 2020}}
• Arduino BASIC – adapted from Gordon Brandly's 68000 Tiny BASIC, ported to C by Mike Field.
• TinyBasic Plus – adapted from Arduino BASIC by Scott Lawrence.{{cite web | url=https://github.com/BleuLlama/TinyBasicPlus | title = TinyBasicPlus| website = GitHub}}
• Half-Byte Tiny Basic – adapted from Arduino BASIC.{{cite web | url=https://halfbyteblog.wordpress.com/2014/11/26/its-here-half-byte-tiny-basic-2-for-arduino-and-compatibles-3/ | title = It's here! Half-Byte Tiny Basic 2 for Arduino and compatibles| date = 27 November 2014}}
• Tiny Basic on the micro:bit – adapted from Palo Alto Tiny BASIC.{{cite web | url=https://halfbyteblog.wordpress.com/2020/03/27/running-tiny-basic-on-the-micro-bit/ | title = Running Tiny Basic on the Micro: Bit| date = 28 March 2020}}

In 2002, Emmanuel Chailloux, Pascal Manoury and Bruno Pagano published a Tiny BASIC (lacking {{code|GOSUB}}/{{code|RETURN}}) in Developing Applications with Objective Caml as an example Objective Caml application.{{cite book |last1=Chailloux |first1=Emmanuel |last2=Manoury |first2=Pascal |last3=Pagano |first3=Bruno |title=Developing Applications with Objective Caml |date=2002 |publisher=O'Reilly |location=France |isbn=2841771210}}

In 2013, Alex Yang published an implementation in Python.{{cite web |url=https://github.com/aleozlx/tinybasic |title=aleozlx/tinybasic |website=GitHub |access-date=2020-09-20}}

In 2019, Sergey Kuznetsov published a version in Ruby.{{cite web |url=https://sourceforge.net/p/paloalto-basic/code/ci/master/tree/paloaltobasic.rb |title=PaloAltoTinyBasic |access-date=2020-09-20}}

Also in 2019, Oscar Toledo Gutierrez published bootBASIC, which fits in the 512 bytes of the boot sector of an 8086/8088 machine, making it the smallest BASIC implementation yet. To accomplish this, the language drops relational operators (IF statements work on nonzero values), limits lines of code to 19 characters or less, and doesn't update the display when backspace is pressed.{{cite web |last1=Williams |first1=Al |title=bootBASIC Fits Your Favorite Language in the Boot Sector |url=https://hackaday.com/2019/07/31/bootbasic-fits-your-favorite-language-in-the-boot-sector/ |website=Hack A Day |date=31 July 2019 |access-date=26 March 2022}} Additionally, it lacks GOSUB and RETURN but does include a RND function (without arguments, returning a value between 0 and 255).{{cite web |last1=Gutierrez |first1=Oscar Toledo |title=bootBASIC is a BASIC language in 512 bytes of x86 machine code. |url=https://github.com/nanochess/bootBASIC |website=Github |access-date=26 March 2022}} The language uses an array to store program lines, requiring 20,000 bytes to do so.{{cite book |last1=Gutierrez |first1=Oscar Toledo |title=Programming Boot Sector Games |date=27 July 2019 |publisher=Lulu |isbn=978-0-359-76262-0 |page=155}}

In 2023, [https://projects.drogon.net/author/gordon/ Gordon Henderson] published a Tiny Basic implementation in 6502 assembler. It is influenced by NIBL and can run in as little as 3.5KB of ROM requiring at least 1KB of RAM for data and program storage. It supports DO/UNTIL, FOR/NEXT, simple strings and memory peek/poke (byte or 16-bit word), GOSUB/RETURN, CALL, RND with facilities for hexadecimal input and output.{{Cite web |last=Henderson |first=Gordon |date=2023 |title=A Tiny Basic for the 6502 |url=https://projects.drogon.net/gibl/ |website=Drogon Projects}}

The following table compares the language feature of Tiny BASIC implementations against other prominent BASICs that preceded them.

• BASIC interpreter
• Copyleft
• Dartmouth BASIC

{{notelist}}

{{reflist}}

• {{Cite journal |journal=Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Running Light Without Overbyte |title=TB Code Sheet |volume=1 |issue=1 |date=December 1975 |url=https://archive.org/details/dr_dobbs_journal_vol_01/page/n1/mode/2up |ref=CITEREFDobbs1976}}
• {{cite book |last1=Manes |first1=Stephen |author-link=Stephen Manes |first2=Paul |last2=Andrews | title = Gates: How Microsoft's Mogul Reinvented an Industry and Made Himself the Richest Man in America | publisher = Touchstone, Simon and Schuster | date = 1994 | location = New York | isbn = 0-671-88074-8}}

• [http://www.IttyBittyComputers.com/IttyBitty/TinyBasic/TBuserMan.htm Tiny Basic User Manual] and [http://www.IttyBittyComputers.com/IttyBitty/TinyBasic/TBEK.txt Experimenter's Kit] – by [http://ittybittycomputers.com Tom Pittman]
• [http://www.swtpc.com/mholley/BASIC_2/Uiterwyk.htm Robert Uiterwyk's BASIC] {{Webarchive|url=https://web.archive.org/web/20110107204656/http://www.swtpc.com/mholley/BASIC_2/Uiterwyk.htm |date=2011-01-07 }} and [http://www.swtpc.com/mholley/NewsLetter1/MicroBasic.htm Robert Uiterwyk's Micro Basic] {{Webarchive|url=https://web.archive.org/web/20120205030911/http://www.swtpc.com/mholley/NewsLetter1/MicroBasic.htm |date=2012-02-05 }} – A MC6800 tiny BASIC later sold with the SWTPC 6800 computer
• [http://www.vintagecomputer.net/cisc367/DrDobbs%20Apr%2076%20Minol%20Listing%20w-corrections.pdf MINOL] – Erik Mueller's MINOL – Tiny BASIC with strings for Intel 8080
• [http://sourceforge.net/projects/tinybc Tiny BASIC] – A version for the curses character screen handling library
• [http://www.aldweb.com/articles.php?lng=en&pg=7407 tinyBasic] – An implementation written in [http://www.aldweb.com/articles.php?lng=en&pg=5350 iziBasic]
• [http://www.runbasic.com/?_page=tinybasic.bas Tiny BASIC] – A live web version, ported to Run BASIC from iziBasic
• [https://github.com/pankuznetsov/Palo-Alto-BASIC-in-Ruby-less-then-in-500-lines Palo Alto BASIC less than in 500 lines] – Example BASIC interpreter written in Ruby.
• [http://www.thisiscool.com/tinybasic.htm TinyBasic] – A port of [http://www.ittybittycomputers.com/IttyBitty/TinyBasic/TinyBasic.c Tom Pittman's TinyBasic C interpreter] to Java, C# and Adobe Flex. Includes live web versions.
• [https://www.pouet.net/prod.php?which=85197 TinyBASIC Windows] – A Windows version of TinyBASIC
• [http://rosettacode.org/wiki/Category:Tiny_BASIC Category:Tiny BASIC] Tasks implemented in Tiny BASIC on [http://rosettacode.org rosettacode.org]
• [http://rosettacode.org/wiki/Category:Palo_Alto_Tiny_BASIC Category:Palo Alto Tiny BASIC] Tasks implemented in Palo Alto Tiny BASIC on [http://rosettacode.org rosettacode.org]

{{BASIC}}

Category:Microcomputer software

Category:BASIC interpreters

Category:Copyleft

Category:BASIC programming language family

Category:Programming languages created in 1975