93 Z disassembly - I have jsrs to non prom location.

[Robert W. Hughes]

>  I did find some odd code that does jsr into the $5000 range,
> the prom is mapped from $8000-$FFFF, so $5000 would have to be
> built into the computer's internals.    There about 10 of these jsrs
> to different addresses in the $5000 range. 

GM had a diagnostic device that apparently allowed monitoring and
controlling/changing operation of the ECM for development purposes. It
mapped itself into the $5000 range when plugged in. There should be
several places in your software where a set of locations in the $5000
area is checked for a specific set of values and if found jmp/jsr
transfers are then made to this area. These addresses show at $5800 and
above in my ECM (7170)
-- 
Robert W. Hughes (Bob)
BackYard Engineering
Houston, Texas
rwhughe at hal-pc.org