BackBit C64 Firmware 1.9.8

- Moved most handler routines to clock-based response, which improves reliability, but may cause issues on a few games.

- Improved interrupt and stack handling on KERNAL routines, fixing a bug introduced in 1.8.7 and occasional crash in Ultima IV Remastered

- Some games may be negatively impacted, for example Simpsons EasyFlash. Please report any incompatibilities introduced in this version.