GSX AppleSoft BASIC Interpreter

Source Editor

0 lines

Apple Video Display

40 columns × 24 rows

INPUT

READY · GSX AppleSoft BASIC Interpreter ready Single-file HTML · MIT License · Michael Roberts

Example Programs

Select an example to replace the editor contents. The Apple video display is not changed until you press Run.

Help and Command Reference

Keyboard shortcuts

`Ctrl/⌘` + `Enter`	Run program
`Esc`	Stop execution or close the active dialog
`Ctrl/⌘` + `L`	Normalize/List Program in editor
`Ctrl/⌘` + `S`	Save BASIC source
`Ctrl/⌘` + `Shift` + `F`	Toggle application fullscreen
`Ctrl/⌘` + `Shift` + `P`	Enter presentation mode
`F1`	Open Help

Core AppleSoft

PRINT LET INPUT GET IF...THEN GOTO ON...GOTO FOR...TO...STEP NEXT GOSUB RETURN STOP CONT DATA READ RESTORE DIM DEF FN ONERR RESUME HOME HTAB VTAB INVERSE NORMAL TEXT

Apple II graphics

GR COLOR= PLOT HLIN...AT VLIN...AT HGR HGR2 HCOLOR= HPLOT...TO

Apple IIGS SHR extensions

SHR 320|640 SHRCLEAR SHRPALETTE SHRRGB SHRCOLOR SHRPLOT SHRLINE SHRRECT SHRFILL SHRFLOOD SHRBLIT SHRSCROLL SHRSPRITEDEF SHRSPRITE SHRSPRITET SHRTEXT SHRTEXTAT SHRTEXTCOLOR SHRTEXTPRINT SHRBOX SHRFRAME SHRPOINT() TICK WAIT SHRBEGIN SHREND

Speculative XSHR extension

XSHR 320,200,256 XSHR 320,400,256 XSHR 640,400,16|32|256 XPALETTE bank XRGB bank,index,r,g,b XPALETTECOPY source,destination XSCAN y,palette XCOLOR index XCLEAR color XPLOT x,y XLINE x1,y1 TO x2,y2 XRECT x1,y1 TO x2,y2 XFILL x1,y1 TO x2,y2 XPOINT(x,y) XBLIT...AT XSCROLL XSPRITEDEF XSPRITE XSPRITET XSPRITEDEL XTEXTAT XTEXTCOLOR XTEXTCLEAR XTEXTPRINT XBEGIN XEND

XSHR is a fictional browser-native extension representing a speculative post-Apple-IIGS graphics architecture. It is not emulation of released Apple hardware.

The List Program button sorts and normalizes the editor. The Renumber button numbers every nonblank physical editor row as 10, 20, 30… and updates recognized control-flow references. Rows are retained even when they contain REM text, invalid BASIC, or no original line number. Visual word wrapping in the editor is ignored because renumbering operates only on actual newline-delimited source rows. Neither command prints to the Apple video display.

About

GSX AppleSoft BASIC Interpreter

A standalone browser-based GSX AppleSoft BASIC Interpreter with Apple II text and graphics modes, Apple IIGS-inspired Super Hi-Res extensions, and the fictional browser-native XSHR graphics family.

Author: Michael Roberts
Release: Release Candidate 1
License: MIT
Architecture: Single self-contained HTML file with no external dependencies.
Creation Date: June 22, 2026
Revision Date: June 22, 2026
Copyright: © 2026 Michael Roberts

www.mygiantbrain.com www.krellstudios.com

The SHR command vocabulary is a browser-native extension and does not redefine historical AppleSoft graphics commands.

Phase 2.2 correction: Restored the proven per-statement cooperative scheduler for all BASIC programs, retained throttled Diagnostics rendering, and corrected the XSHR demo packaging.