It’s taken a long time, and we really appreciate your patience. We have finally released the IPF library source code, under the same terms as MAME (non-commercial use). Other licenses may follow.
This code also includes a cycle exact, low level WD177x emulator that works at the signal (not command) level. This took quite some investigative work digging up the appropriate datasheets, and a huge number of hours by multiple people in testing, including many many hours spent verifying the behaviour of real hardware. It was very important to us, so we spent a long time on it. There is a lot of information in the WIPs about it in fact. We think it is pretty neat!
The release currently has two forks, one for the main release and the other for ports. A later release might merge both, but we felt it was more important to get it released instead of further polishing it.
Enjoy. If you like this, please consider donating. Thanks!