For more information on DOS 3.3 and ProDOS commands, see their FAQ at On Aug 30, 10:17 pm, Jcarlson1701 wrote: On Aug 31, 4:17 am, Jcarlson1701 wrote: I have a slightly different feedback - I assume you are an Apple II, MD-BASIC is Applesoft preprocessor, it is not a compiler. Here's a general rundown of the rules: 2 (or more) adjacent 1 bits display as white. 'GOTO n' transfers control to line n, if it exists. All variables can be set by '[LET] varb = expression'. It can also print several of these at once if semicolons (';') or commas are between the sections: 'PRINT "The Answer:"; 2+2'. For integer and floating point (real) math, normal arithmatic precedence and operations are followed. BASIC emerged in 1964 on the Dartmouth College Time Sharing System. 'PRINT : PRINT CHR$(4)"CATALOG"'. It is assumed that the reader has at least a basic introduction to programming, such as variables, flow of execution, as well as a general understanding of either DOS 3.3 or ProDOS for the Apple II. Like some kind of arcane dark magic, the program knew your name and talked back to you!,, The '=' operator behaves as an assignment the first time it's encountered in an assignment, and equality at all other times. With the proliferation of Applesoft BASIC addons in the 70s, 80s and 90s, this FAQ does not attempt to cover any of them, though it may make reference to a few of them from time to time. Some sample files are present in a server-side store loaded on-demand into a client-side virtual file system (VFS). A simple default system beep can be done with a 'PRINT CHR$(7)' (control-G); Applesoft BASIC can also only do simple clicks. The Apple II stood out because of its low cost and color graphics. PDL() returns a value between 0 and 255; the 'center' is approximately 127. Make sure you use a machine with Applesoft in ROM, such as the Apple II Plus or later, or an original Apple II with the proper language card. Overall program parsing is done with a recursive descent parser. 'PRINT's are not really buffered-- they appear as soon as ready, even if the trailing carriage return is surpressed. This is only available once you've started up your computer with DOS 3.3 or ProDOS. parsing is done while lexing: REM consumes anything to the next for more of them. How-To Geek is where you turn when you want experts to explain technology. The program will ask you for input with a question mark ( ? II Programmer's Reference. Those differences may be noted from time to time, but those notations may not be complete yet. POKE 49166,0 sets any Mousetext characters onscreen to flashing charactes, and 49167,0 turns all flashing text to Mousetext. It can get integers, reals, and strings, as well as getting several at once. DOS 3.3 and ProDOS command line commands are not included in this FAQ; they have a FAQ of their own at [This section is not quite yet written. operator, 'SCRN(x,y)' will return the color (0-15) of the pixel at coordinated x,y. You hear a beep, and then see a “]” prompt with a blinking cursor. object representing the program. However, these, are wild hacks, and not very usable or easy to generate/modify. Arrays can be of integer, real, or string type. 'BRUN filename[,Astart]' loads a binary file and starts executing it. ', flashes the cursor and lets the user type in a number. In addition, DOS 3.3 wants the control-D to be the first character in an output line; if you are having troubles, prepend a blank 'PRINT' before the command, e.g. Each time you type a line of code with a certain line number, BASIC replaces whatever was previously stored on that line number with the new input. This document can be freely copied so long as 1) it is not sold, 2) any sections reposted elsewhere from it are credited back to this FAQ with the FAQ's copyright info and official WWW location (URL: left in place. It does this by replacing each character on the text screen with two blocks. 'END' will stop execution of the currently running program and cleanly exit to the Applesoft prompt. Crossing loops such as 'FOR I=1 TO 5: FOR J=1 TO 3: NEXT I: NEXT J' will cause errors, and generally are a bad idea. Version: 0.27 'VTAB n' will set the cursor's vertical position on the screen-- 1 is the top row on the screen, 24 is on the bottom. Strings are dynamically allocated, and use their length plus 1 in bytes. Apple ][js uses JavaScript to simulate the circuitry of a real Apple II in software. Writing your own program is an option available on your Apple. Up to 4 single-axis analog devices can be connected to an Apple II; these can be either paddles or 2-axis joysicks. The Apple II shipped with two major versions of BASIC over the years: Wozniak’s Integer BASIC, and Applesoft. NOTE: this FAQ is in beta form, and is still being written. (2) Use no unneeded spaces-- only type them if they're in the middle of a string (" ") or a DATA statement. There is no else clause in the language, but it is easy to get around that-- put a GOTO at the end of the IF line to skip the next line(s) of code, where the "else" clause is. Posting-Frequency: monthly To extend these basic types, you can make arrays. with a standard recursive descent parser. You'll need a machine language addon package to use this mode; several existed, such as Beagle Bros' Beagle Graphics. string-literal, Applesoft BASIC was a dialect of BASIC supplied with the Apple II series of computers. For example, to read from the 10th record, 'PRINT CHR$(4)"READ filename,R9"'. Of course, if you have a real Apple II, you can follow along, as well. All continuing characters ([A-Z0-9]) past the first two are ignored-- NA is the same as NAME. Expressions are parsed size of an array is limited only by the available memory. Otherwise, we’ll be using a handy Apple II emulator called Apple ][js created by Will Scullin. Other beep tones and music require machine-language subroutines which are currently beyond the scope of this FAQ. The FRE() statement was built into Applesoft to both report on memory management and perform garbage collection. Thousands of amazing games and applications have been programmed in Applesoft over the past 42 years, so the sky’s the limit of what you can do with it. Basically, you’ll be running an entire Apple II system in a web browser (it works best in Google Chrome). Normally, lomem is the top of your basic program, and himem is the highest available address under the OS and its buffers; you should not lower the lomem or raise the himem unless you are darn sure what you're doing. DOS commands may be much harder to fool. If you get a disk listing of files, you're under DOS 3.x or ProDOS. Applesoft BASIC is rather poor in its memory management, mostly at the cost of backwards compatability-- a standard (no machine-language assistance) program that runs on a //e will run on any other Apple II with at least 64K. 'STOP' halts the currently running program with a message; you can use 'CONT' from the prompt to attempt to restart where you left off. Expression x is evaluated, and if true, then the rest of the line is parsed. Music in applesoft basic Sign in to follow this . Error codes not possible within a program: ?Can't Continue Error