The JEF file
Janome · Elna
Getting it onto the machine
USB stick — copy the file into a folder named EMBF. On the stick, not inside another folder.
How the file is built
Two signed bytes per stitch, dx and dy in tenths of a millimetre — the same simple shape as Melco EXP. 80 01 is a colour change, followed by a stitch of zero.
Colours
The colour list sits in the header, so the machine can show the thread order before the first stitch is sewn.
If your machine is not listed
Use DST. Every commercial machine reads it, and most home machines will too — it is the format the trade falls back on. The stitches are identical in all seven; only the wrapper differs, so «which format?» is a question about your machine and never about quality.
Make a JEF file — see the stitches first
Written from our own writer for this format, in src/engine/format.