You need to create the 16-byte NES header yourself and stick it on the front of the .bin, resulting in a valid .nes file (i.e.
copy /b header+dump.bin > game.nes).
The format is
well-documented and well-understood. The most complicated part is getting the mirroring and mapper number correct; the latter may require that you learn the
NES 2.0 header format instead, but it's circumstantial (i.e. depends on what all is going on with the cart). Start with the original NES header and work from there; don't worry about 2.0 unless it turns out you need it.
If you can't get it working, odds are the mapper is wrong; to solve that, you're going to need to disclose details of said prototype, including very high resolution board PCBs so traces can be analysed and the actual hardware details reviewed.
And please don't be one of those people who dumps a ROM and botches the NES header -- this has caused a lot of pain over the past 20+ years.
Ask us and we will help you get it right.@Moderators: this needs to be moved to a different sub-board, ex. Hardware, as this is not NESdev related.