Teletext Studio

Teletext Studio

Tools

Text — Click to place cursor, then type. Arrow keys navigate. Enter moves to next line. Backspace deletes left, Delete clears at cursor. Tab advances 4 columns.

Paint Blocks — Click/drag to paint individual sub-blocks (6 per cell, 2×3 grid). Right-click erases sub-blocks. Hold Shift while dragging to constrain to straight horizontal lines. Press Space to place a full block at the cursor.

Recolor — Flood fill: click a region to recolor all connected cells that share the same fg, bg, and type (text/mosaic). Keeps content, changes fg/bg to your active colors.

Eraser — Click/drag to clear cells to default (black background, white foreground, space).

Pick Color — Click any cell to grab its foreground and background colors.

Select/Move — Drag to select a rectangular region. Click inside the selection and drag to move it. Press Delete or Backspace to clear the selection.

Row Options

Double Height — Toggle: makes the current row twice as tall. The row below automatically becomes the bottom half.

Colors

Click the foreground/background palette swatches in the left panel. In non-text tools, keys 1–8 select foreground color, Shift+1–8 select background color.

Colors: 1=Black, 2=Red, 3=Green, 4=Yellow, 5=Blue, 6=Magenta, 7=Cyan, 8=White

Keyboard Shortcuts

Ctrl+Z / Cmd+Z — Undo

Ctrl+Shift+Z / Cmd+Shift+Z — Redo

Arrow keys — Move cursor (all tools)

Escape — Deselect

Delete / Backspace — Clear selection (Select tool)

CRT Overlay

Toggle the CRT button to enable a 5-pass WebGL shader that simulates scanlines, phosphor persistence, bloom, and aperture grille.

Pages & Subpages

Use the right panel to manage pages (insert, duplicate, delete) and subpages. Each page has a hex page number (100–8FF). Subpages cycle automatically in the viewer.

Fastext Links

Set label text and target page number for each color (Red, Green, Yellow, Cyan) in the right panel. When set, a colored navigation bar renders on row 24 in the viewer.

Import / Export

Export .t42 — Save all pages as a binary T42 file (broadcast-compatible format).

Import .t42 — Load all pages from a T42 file. Supports raw 42/46-byte blocks, PES-framed DVB data units, and auto-detects bit-reversed captures.

Import Image — Convert a bitmap image to full-color mosaic art. Configure start position, size, and background color in the import dialog.

How Colors Work

Teletext uses control codes to set colors. Each color change requires one cell position for the control code. The compiler automatically inserts these codes, sacrificing one cell of content at each color transition. For best results, leave a blank column before color changes.

Import Image