I had a bit of a struggle finding the service manual for the FT1000MP Mark V (200W) version so I’ve found a copy and have it stored locally.
If you are in need of this, please let me know and I’ll “wetransfer” it to you rather than wasting my web bandwidth.
I’ve just found this page on the internet whilst I was doing a search to track down exactly how the IDBT control works on my Yaesu FT1000MP Mark IV (Mk 5). It stands for something like Interlocked Digital (analog) Bandwidth Tracking and it’s part of the EDSP controls. Thierry explains it better than me, however I’m a happy bunny now because I can get the Mk5 sounding like my original MP
Anyway, these deeper (advanced..?) instructions beat the instruction manual hands down. Merci Thierry!