Is there a complete and programming language independent specification available for the FT8 digital mode? Detailed enough to implement both transmit and receive SDR software from scratch in two different programming languages?
If not, for what popular digital modes are full (programming language and computer independent) specifications available?
The goal is to have a target for an advanced SDR programming exercise in an any arbitrary (Turing and computationally complete) programming language (such as Perl or Swift or Basic or ARM m0 assembly, etc.). This would be for the software equivalent of building ones own radio from basic components (L, C, R, FETs, tubes, wires, etc. -> lines-of-code of elementary ops)
Added: A specification for reliable very-weak-signal (below the noise floor) protocol that is legal to use in within the U.S. amateur bands is preferred. A specification that requires advanced programming and DSP knowledge is not a problem. I do not consider code (other than platform-agnostic algorithmic pseudo-code) or precompiled binaries to be a proper specification. It would be desirable to have the specification complete enough that two independent teams using two different programming languages and platforms could interoperate (communicate) using their implementations of the specified protocol.