The file counts lamps, not feet. With RGB on, set Bytes / frame to lamps × 3, then click Apply layout. Columns only wraps the preview on screen.
Strip length guide
Count the lamps on the strip. If you only know the length, use the reel density. 60 lamps per meter is about 18 per foot, 30 per meter is about 9 per foot, and 144 per meter is about 44 per foot.
- 256 lamps, 768 bytes. The loaded patterns. About 14 feet at 60 per meter.
- 18 lamps, 54 bytes. About 1 foot at 60 per meter.
- 91 lamps, 273 bytes. About 5 feet at 60 per meter.
- 300 lamps, 900 bytes. About 16 feet, or 5 meters, at 60 per meter.
A short strip uses a smaller Bytes / frame. Set Columns to the lamp count and the preview is one row. A long strip uses a larger Bytes / frame. Lower Columns when the row does not fit. For a strip folded back and forth, set Columns to the lamps in one row and turn on Serpentine rows.
Each program is one 64 KB slot. 256 lamps fit 84 frames. 512 lamps fit 42 frames. A short strip fits many more frames.
Catalog patterns are built at 256 lamps. For another length, use New show, set Bytes / frame to lamps × 3, and click Apply layout before you draw. Changing the size of a finished pattern reslices the same bytes onto the new frame size.