Editing TI BASIC (TI 99/4A) (section)

==Extended BASIC==
[[File:TIextendedbasic.JPG|thumb|TI Extended BASIC cartridge.]]

TI BASIC was located in the system's internal [[read-only memory|ROMs]]. In 1981, TI released a plug-in [[ROM cartridge]] that added additional functions to the existing code, improving the language in a number of ways.{{sfn|Shaw|1983}} Known as Extended BASIC, it was a highly anticipated addition to the platform.<ref name=kaplan>{{cite magazine |first=Gary |last=Kaplan |magazine=TI 99er |date=June 1981 |title=Extended BASIC Review |url=http://www.mainbyte.com/ti99/software/s_carts/ext_basic.html}}</ref>

Among the changes was the addition of the ability to have multiple statements on a line. Using multiple statements may improve performance; loops that are implemented in a single line run much faster. Additionally, statements could now span several lines. As the underlying dialect already used the colon for string separators, Extended BASIC used the double-colon for this purpose. Confusingly, as a statement with two colons was also possible in TI BASIC, for instance, {{code|PRINT "A"::"B"}}, which would output "A", a blank line and then "B", so these statements required a space to be added in Extended BASIC, {{code|PRINT "A": :"B"}}.{{sfn|Shaw|1983}}

Another overdue addition was that {{code|IF}} statements could now perform arbitrary statements, rather than only a {{code|GOTO}}. In Extended BASIC one could write a simple statement like {{code|IF X>10 THEN X{{=}}X-1|basic}}. This also worked in the {{code|ELSE}} clause, allowing statements like {{code|IF A{{=}}4 AND B{{=}}6 THEN R{{=}}10 ELSE PRINT "OOPS"|basic}}.{{sfn|Shaw|1983}}

Other additions include a small selection of new statements, including {{code|ACCEPT}}, {{code|IMAGE}}, {{code|LINPUT}}, {{code|ON BREAK}}, {{code|ON ERROR}}, {{code|ON WARNING}}, {{code|SUB}}, {{code|SUBEND}} and {{code|SUBEXIT}}. The last three statements are used for [[structured programming]], allowing the creation of named [[subroutine]]s. Extended BASIC also included a number of new functions and especially CALLable routines. Among the latter was a library of sprite commands, including ones that created motion that continued automatically.{{sfn|Shaw|1983}}

===Speech synthesis===
When equipped with the TI Speech Synthesizer, TI Extended BASIC users could also [[Speech synthesis|generate speech]] from a predefined vocabulary as easily as writing text on-screen.  For example, the following line of text would cause the speech synthesizer to identify the computer:{{sfn|Shaw|1983}}

  CALL SAY("HELLO I AM A #TEXAS INSTRUMENTS# T I NINETY NINE FOUR A HOME COMPUTER") 

Multi-word phrases are [[delimiter|delimited]] with the # symbol, as <code>#TEXAS INSTRUMENTS#</code> in this example. Using a word not included in the speech synthesizer's built-in vocabulary of 338 words and phrases would cause it to slowly spell out the word. TI's Terminal Emulator II cartridge provided [[text-to-speech]] functionality.{{sfn|Shaw|1983}}