brings us closer to basic operation.
- Verified/updated ROM vector entries for many systems, and new vector
table entries for LC 520, LC 575/577/578, and Quadra 950
- Implement a new machine class (MACH_CLASSQ2) for the LC 575 series
- Use the ptest040() helper function in get_physical().
Also, in straytrap(), only enter the debugger #ifdef DDB.