GenX‑DOSWIKI SearchPromptArticle↩ Site

The virtual filesystem lives in prompt/javascript/fs.js as a JS array called fs. Every directory and every file is an object in that tree. No server, no database — edit the file, hard-refresh, the prompt picks up the change.

What a node looks like

var fs = [{
  name: 'C',
  directories: [ ... ],
  files: [ ... ]
}];

A node is one of:

Shape Means
{ name, directories, files } a directory
{ name, link } a "file" that opens a URL when executed
{ name, data } a "file" whose data is run as a batch script when executed
{ name, com } a program: com names a routine in COM_PROGRAMS to call when executed

hidden: true on a node hides it from dir output (still navigable via cd).

C:\ holds two com files, COMMAND.COM and VER.COM, and both are on the PATH: a program is looked for in the current directory first and then in each directory listed in GENX_PATH, which is how DOS searched. TYPE on a com or on an .exe prints the bytes of a program rather than its contents.

{ name: 'GITHUB.COM', link: 'https://github.com/yourname' }

Drop it into any directory's files array. The user can cd into the directory and type github.com to open it.

Adding a batch file

{ name: 'HELLO.BAT',
  data: '@echo off\nsetcol 2e\necho Hello, world!\nsetcol 07\necho.' }

Lines are separated by \n. Supported batch commands: anything in Commands plus any filename present in the current directory.

Adding a directory

{ name: 'MUSIC',
  directories: [],
  files: [
    { name: 'BANDCAMP.COM', link: 'https://yourname.bandcamp.com' }
  ]
}

Adding a system menu (numbered list)

The standard pattern for a system with several titles is a directory whose menu.bat prints a box-drawn menu, plus numbered .bat shortcuts that each run a named .exe launcher.

{ name: 'GAMES', directories: [], files: [
    { name: 'menu.bat', data: '@echo off\ncls\necho ╔═══...╗\n...echo.\n' },
    { name: '0.bat',    data: '@echo off\ncd ..\ncd ..\nmenu\n' },
    { name: '1.bat',    data: 'mario\n' },
    { name: '2.bat',    data: 'contra\n' },
    { name: 'mario.exe',  link: '../systems/jsnes/play.html?game=mario' },
    { name: 'contra.exe', link: '../systems/jsnes/play.html?game=contra' },
] }

The menu.bat data string renders rows like ║ 1. Super Mario Bros. (1985) ║ — title first, year last is the project convention (see Menu box format below).

The flow: the user types a number → it runs the matching N.bat → which runs <key> → which resolves to <key>.exe (the link: entry) → which opens the emulator URL. Typing <key> at the prompt does the same thing, which is what keeps the menus self-documenting for anyone who tries dir.

For a real example see the NES or C64 blocks in fs.js.

Standard menus use double-rule CP437 borders with a 45-char inner width.

 ╔═════════════════════════════════════════════╗
 ║              CENTERED HEADER                ║ ◄── header (45 chars between ║)
 ╠─────────────────────────────────────────────╣
 ║                                             ║ ◄── blank spacer row
 ║   1.  Some Title                     (1985) ║ ◄── 3-column: # Title (Year)
 ║   2.  Another Title                  (1986) ║
 ║                                             ║
 ║  11.  BASIC system prompt                   ║ ◄── prompt rows have no year
 ║                                             ║
 ║   0.  Back                                  ║ ◄── always last
 ║                                             ║
 ╠─────────────────────────────────────────────╣
 ║        Type a number and press ENTER        ║
 ╚═════════════════════════════════════════════╝

Entry row layout (45 chars between borders): 3 columns — number, title, year. Games sorted by year ascending, alphabetical within year.

 ║   N.  Title field                    (YYYY) ║
  ├─────┤├─────────────────────────────┤├────┤│
     7                 31                 6   1
   "N.  "        title (left)          (YYYY)

Two things to remember:

Boot behaviour

autoexec.bat runs automatically on load. Its default data is just menu\n — which runs the root menu.bat. The root menu.bat in turn does cd systems\nmenu\n, dropping the user straight into the EMULATOR LAUNCHER.

To boot to a different starting place, override menu.bat (or autoexec.bat):

{ name: 'autoexec.bat', data: 'cd systems\\console\\nes\\games\ncls\ndir/w/o\n' }

To set colours at boot, prepend setcol:

{ name: 'autoexec.bat', data: '@echo off\nsetcol 02\nc:\ncls\nmenu\n' }

Common combos:

Code bg / fg
07 black / light grey (default)
0f black / white
17 dark blue / light grey
02 black / dark green
0a black / green
0e black / yellow

See Font System for the 16-colour palette.

A few things we've learned the hard way