heh, probably - the hard part is the code that's hacking the stack pointer and return address on the stack out from underneath you when they do a context switch (rather than V7's C-standard setjmp()/longjmp() semantics). That part needs diagrams.

The easier part I was trying to explain was the meaning of the SSWAP and the return(1) which effectively bring you back somewhere different returning a 1 where another routine returns a 0 (a bit like setjmp/longjmp) - this routine when called to do a context switch usually doesn't return anything