Atari ST series Technical Reference Manual page 399

clouds equal to the exception number. TOS uses the following portion of
the User Interrupt Vector space to save the processor state information
when a crash occurs. This memory area is not cleared by a system reset,
but may be overwritten by subsequent crashes.
896-899
If the system was able to save the processor state, it sets this variable to
$12345678 as a flag that the following information is valid.
900-931
The contents of the eight data registers are saved here, starting with D O
and ending with D7.
932-963
The contents of the eight address registers are saved here, starting with AO
and ending with A7. Note that A7 represents the Supervisor Stack Pointer,
not the User Stack Pointer, which is saved in proc__usp, below.
964-967
The first byte of this longword is the exception number that caused the
crash.
968-967
The User Stack Pointer is saved here.
972-1003
The top 16 words of the supervisor stack are saved here.
These vectors are not guaranteed to appear at this location, so to change
them, use the BIOS function Setexec(), with an exception number of
$100-$107.
ST Memory Map
proc__lives
proc__dregs
proc__aregs
proc__pc
proc__usp
proc__stk
Logical Vectors
($380-$383)
($384-$3A3)
($3A4-$3C3)
($3C4-$3C7)
($3C8-$3CB)
($3CC-$3D B)
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