GUIDE · EDITORSALPHA · USE AT YOUR OWN RISK

Editors

Two GUI editors cover the pixels: the Screen Editor for whole MODE 0–7 layouts, the Sprite Editor for EGFX frames. Both write real project formats, not exports you throw away.

Beeb Screen Editor

Open any .bscreen file from the Screens view. The canvas renders the chosen BBC mode (0–7) faithfully, including MODE 1's four logical colours.

• Tools - rectangles, ellipses, lines, dots, text, sprites, progress bars and banners.
• Objects stay live - move and resize with handles, reorder z-order, edit properties; nothing is flattened.
• Export EGFX - generates PROCeg* calls (MODE 1, OSWORD &C0) ready to paste into a BASIC program. Constraint warnings - 8-aligned text, 40-character cells - appear in the Beeb-dev output channel before they bite at runtime.
• Export VDU - portable PLOT-code that runs in any mode with no ROM installed.

Beeb Sprite Editor

Click any sprite under Assets → Sprites and the pack opens as an editor tab: left button paints, right erases, with a transparent swatch in the MODE 1 palette.

• Frames - navigate, duplicate and delete frames (EGSP allows up to 16), with an animated preview and FPS slider.
• Phase alignment - a strip previews the frame at each of the four pixel offsets within a MODE 1 screen byte. EGFX does not store pre-shifted copies: sprites at an X that is a multiple of 4 use its fast blitter.
• Sizes and projects - EGSP v3 packs with square 2, 4, 8, 16 or 32-pixel frames, and native EGFX sprite projects open directly in the editor; Save As chooses a path for a new resource.
• Save behaviour - Ctrl+S re-encodes and writes back: the whole file for on-disk packs (SPRITES, NFSPRITES, *.egsp), spliced at offset 0x100 for companion ROM images whose frame count and size stay fixed.
• Discovery - packs are indexed by content, not filename: any file starting with the EGSP magic and any 16 KB ROM carrying a pack at 0x100 appears automatically, so project packs like Nightfall's NFSPRITES or SWORDS are editable in place.

From editor to game

Screens export as drawing calls, sprites re-encode into packs the ROM loads - the same assets the EGFX reference documents from the other side. For the resource workflow (uploading packs, companion ROMs, batches), see functions 16–18 and 33–35.