Instructions

This tool lets you design a full 16×16 TI-99/4A sprite using four 8×8 quadrants: Top Left (TL), Top Right (TR), Bottom Left (BL), and Bottom Right (BR). Draw directly in the grids and the tool will generate the correct hex values and a TI-style preview.

Drawing

• Click a pixel to toggle it on or off.
• Click and drag to paint or erase continuously.
• The tool automatically detects whether you are painting or erasing based on the first pixel clicked.

Quadrant Mirror Buttons

• ⇄ — Mirror the selected quadrant horizontally into its opposite quadrant.
• ⇅ — Mirror the selected quadrant vertically into its opposite quadrant.
• Mirroring always overwrites the destination quadrant.

Hex Controls

• Build Hex ↓ — Converts the current quadrant drawings into hex values.
• Load Hex ↑ — Reads the hex fields and redraws the quadrant grids.
• Important: Build Hex always reads from the grids. If the grids are empty, the hex fields will become zeros.
• Load Hex always reads from the hex fields. Hex must be at least 16 characters per quadrant.

Clear / Fill

• Clear All — Sets all pixels in all quadrants to off.
• Fill All — Sets all pixels in all quadrants to on.

Preview Size

• Choose between 24×24, 12×12, or 8×8 pixel preview sizes.
• This affects only the preview, not the editing grids.

Output

• Each quadrant produces an 8‑byte hex string.
• The combined hex is 32 bytes (TL + TR + BL + BR).
• A ready-to-use CALL CHAR and CALL SPRITE example is generated automatically.