zmakebas+

A browser-based Sinclair BASIC editor, validator, and program-file exporter. Try it out now.

This project is inspired by zmakebas, the command-line tool that converts Sinclair BASIC text files into Spectrum, Timex/Sinclair, or ZX81 program files. zmakebas is primarily a tokenizer and exporter, so it can produce output for BASIC text files that still contain structural errors. zmakebas+ validates the program before export, so those errors can be caught earlier.

What It Does

• Validates BASIC as you edit and highlights syntax errors.
• Supports numbered BASIC listings and label mode.
• Shows the generated BASIC listing for label-mode programs.
• Exports Spectrum-family TAP and WAV files, ZX Spectrum +3DOS files, and ZX81 P and WAV files from the browser.
• Includes a zmakebas compatible command line tool.
• Imports Spectrum-family TAP files and ZX81 P files.
• Runs fully client-side, no backend service is required.

Relationship To zmakebas

zmakebas intentionally performs little syntax checking and leaves many errors to the target machine. zmakebas+ validates the program structure before export, so it can reject BASIC text that zmakebas might still tokenize.

The input format broadly follows the zmakebas README:

• Keywords are case-insensitive.
• Blank lines and lines beginning with # are ignored in label mode.
• A trailing backslash continues a physical input line onto the next line.
• RAND/RANDOMIZE style aliases are accepted where supported by the lexer.
• Keyword-looking variables are allowed in variable contexts where validation can distinguish them, such as LET at=0.
• UDG escapes \A through \U, block graphics, copyright \*, raw byte, literal @, and literal backslash escape forms are supported in exported strings and REM text. Imported Spectrum-family TAP strings and REM text use \* for © (copyright), and readable block-graphic backslash forms for bytes 128 through 143, except for block forms ending in a space at the end of REM text where numeric escapes preserve the stored byte. UDG bytes stay as numeric raw-byte escapes so the stored character codes remain visible.
• Spectrum-family display-control escapes are available as readable raw-byte aliases: \{INK n} and \{PAPER n} use 0..9; \{FLASH n}, \{BRIGHT n}, \{INVERSE n}, and \{OVER n} use 0..1. These can be used anywhere raw byte escapes can be used, including strings and REM text.
• In ZX81 mode, lowercase letters in the program text follow zmakebas compatibility and export as inverse A-Z. Use uppercase text for normal ZX81 letters. Imported ZX81 P files use backslash forms for inverse letters, inverse digits, inverse punctuation, and block graphics where that is roundtrip-safe.

Differences From zmakebas

These differences are intentional unless noted otherwise:

• zmakebas+ validates syntax before export; invalid BASIC may be rejected even if zmakebas would tokenize it.
• Label references are not substituted inside string literals or REM text. Use \@ for a literal at-sign if needed.
• Label names are limited to letters, digits, underscore, dot, and hyphen, and must start with a letter, digit, or underscore.
• Label-only lines do not emit BASIC lines; their labels resolve to the next emitted BASIC line. A label at EOF with no following code is ignored.
• ZX Spectrum Next keywords supported by zmakebas are not currently supported by zmakebas+.

Label Mode

Label mode is enabled by default. It lets you write programs without BASIC line numbers:

goto @start
print "not seen"
@start: print "hello world"

With the default start line 10 and increment 2, this generates:

10 GO TO 14
12 PRINT "not seen"
14 PRINT "hello world"

You can set the generated start line and increment from the toolbar. You can also pin a generated line number in the listing. Here the line number starts at 9000 and increments by 2:

9000+2 DATA "Blah"
DATA "Foo"
DATA "Bat"

Exporting

Choose the target dialect before exporting:

• Spectrum/Timex exports a TAP or WAV file.
• Spectrum with the +3DOS export format exports a +3DOS-compatible file.
• ZX81 exports a P or WAV file.

The export dialog can optionally set an auto-start line.

Web Bundle

The GitHub release includes a static web bundle. Download zmakebas-plus-web-<tag>.zip or zmakebas-plus-web-<tag>.tar.gz, extract it, and host the contents on any static web server. No backend service is required.

Command Line

The GitHub release includes standalone executables for Windows, Linux, and macOS. Download the asset for your platform, extract it, then run the executable. Standalone executables do not require Node.js on the target machine.

zmakebas [-hlp3rv] [-a line] [-i incr] [-n speccy_filename] [-o output_file] [-s line] [input_file]
zmakebas -o hello.tap hello.bas

On Windows, the executable is zmakebas.exe:

.\zmakebas.exe -o hello.tap hello.bas

By default, input is read from stdin and output is written to out.tap. Non-ZX81 mode accepts ZX Spectrum, Spectranet, and TS2068 syntax for compatibility with the original zmakebas token set. Use -p for ZX81 .p output, -l for label mode, -r for raw headerless Spectrum BASIC output, and -3 for +3DOS output. The command line uses the same stricter validation as the web app, so invalid syntax that original zmakebas tokenized loosely may be rejected.

The release also includes a Node CLI bundle. Use that if you prefer to run the JavaScript CLI directly or need a platform-neutral download. It requires Node.js:

node zmakebas.js -o hello.tap hello.bas

Development

Install dependencies:

npm install

Run the development server:

npm run dev

Run checks:

npm run lint
npm run build

Build the static web app locally:

npm run build:web

The local web build is written to dist-web.

Build and run the command-line bundle locally:

npm run build:cli
node dist-cli/zmakebas.js -o hello.tap hello.bas

Build and run a standalone executable locally:

npm run build:exe
./dist-exe/zmakebas -o hello.tap hello.bas

On Windows, the local executable path is dist-exe\zmakebas.exe:

.\dist-exe\zmakebas.exe -o hello.tap hello.bas

Local executable builds use Node single executable applications that requires Node.js 26 or newer.

Project Layout

• src/parser contains the lexer, parser, label preprocessor, and program-file exporters.
• src/cli contains the Node CLI source.
• src/components contains the React UI components.
• src/hooks contains the app-level parser, file, and busy-indicator hooks.
• build-exe.mjs packages the built CLI as a standalone Node single executable.