Early ECU's aren't my thing. Sorry. This is worth a read 748-996 Tuning Software (FREE!) - Speedzilla Motorcycle Message Forums Using Tunerpro, an xdf file and a map bin file it looks like you can locate the rev limit files in the mapping. You then need an eeprom reader/writer/software to load.
there are some fascinating threads on that Forum, but not sure what the current state of 'free' availability is now. Would also suggest that anyone choosing files listed on above only 'open' them rather than 'save' as I found at least one corrupted and sitting on my computer inaccessible now.
That stuff won't work with a 1.5M as it's only for the 1.6M used on the 916 line with the pop-out fuel chip. The 1.5M is the previous generation small square ECU which was used on some SS and Monsters for a couple of years. They are programmable and you can change the rev limit, as we did this on the DD bike. It was actually a 750SSie ECU but we ran a PCIII to offset all the fuel and get it running right. We used the TechnoResearch kit as it was the only one available at the time, but I believe that JP's DucatiDiag also has a version that supports 1.5M now?