Chris Combs (he/him)I think I just realized why the Noritake Itron GU140x32F-7703A VFD starts up in synchronous serial mode no matter what.
(This led some folks to build their own arduino library for it in sync mode.)
The -7703A, for which the datasheet is unobtainium, seems just like the -7003A except that there is a stealth solder jumper on J2 (short = sync, open = async).
I slizzered it open with an xacto and boom it started right up in async
