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Applesoft BASIC in JavaScript
555f8de2ae
See the new sample for details/example. Note that reading 12/24-hour time formats that have colons will not currently work, as the colons will terminate input and result in invisible ?EXTRA IGNORED errors. Fixes #44 |
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| cm | ||
| res | ||
| samples | ||
| tools | ||
| vfs | ||
| .gitignore | ||
| basic.js | ||
| bell.js | ||
| bs.html | ||
| display.css | ||
| dos.js | ||
| favicon.ico | ||
| hires.js | ||
| index.html | ||
| index.js | ||
| LICENSE.md | ||
| lores.js | ||
| printer.js | ||
| README.md | ||
| reference.html | ||
| script.js | ||
| script.md | ||
| styles.css | ||
| tty.js | ||
jsbasic - Applesoft BASIC in JavaScript
This is hosted for playing with at https://inexorabletash.github.io/jsbasic/
Notes & Known Issues
- The BASIC program is compiled to JavaScript before execution. Syntax errors are therefore detected at compile-time rather than at run-time as on a traditional interpreter. For example, the following program would run without errors on an Apple since the erroneous second statement is never reached.
10 END : CHR$(PRINT) - Handling of BASIC code that does not match the canonical
LISToutput format may not behave as on an Apple:- Keyword parsing differs from Applesoft command line. For example
FOR I = S TO Pdoesn't collapse intoFOR I = STOP.
- Keyword parsing differs from Applesoft command line. For example
- Limitations:
- Floating point overflow is only detected on variable assignment.
- Only a subset of DOS 3.3 and ProDOS useful for basic file I/O are implemented.
- Only a small number of common
PEEK,POKEandCALLlocations are supported. - Commands that refer to assembly routines (
&,USR()etc.), shape tables, and tape I/O are not implemented.
- Commands that operate on the program itself (
LIST,RUN,DEL, etc.) are not implemented. - A handful of extensions are made beyond Applesoft BASIC:
- To improve readability, lines may start with
:and continue the previously numbered line. DEF FNcan define string functions==can be used as=CHR$()values > 255 do interesting thingsHSCRN(x, y)allows probing the hi-res screen- hexadecimal literals e.g.
$C010can be used as numbers
- To improve readability, lines may start with