Editing Programming an EEPROM with HEX files (section)

== File format rules ==

The programmer validates every file before it writes anything.  A file that fails validation is rejected outright — it will not half-program your chip.

'''Single-slot files''' (anything except <code>all.hex</code>):

* Exactly '''129 lines'''.
* Address range '''0x000–0x1FF''' — 512 bytes, which is one FV-1 program.

'''Full-image files''' (<code>all.hex</code>):

* Exactly '''1025 lines'''.
* Address range '''0x000–0xFFF''' — the whole 4096-byte chip.
* The EEPROM is cleared to <code>0xFF</code> first, then written from <code>0x0000</code>.
* If <code>all.hex</code> is present it is processed '''first and alone'''.  Other HEX files dropped in the same batch are skipped that cycle, so do not mix a full image with single slots.

These line counts are what the assembler produces naturally.  If your file is the wrong length, it almost certainly did not come from an FV-1 assembler.