8088 vs. 80c88  les at frii.com les at frii.com Tue Feb 24
12:27:32 CST 2009  >In emulation mode (V20) BP = (8080) SP.  But
I don't follow your >logic on how to avoid it.  Why JRT chose to
code things that way, >I'll never know, but it worked on 8080,
8085 and Z80 and not on V20, >so it's a bug.  And a bug in
commercial (i.e. you paid money for it)  The code snippet you
showed seemed to indicate that either you couldn't preform a
call to the same address contained in the stack pointer, or that
you couldn't preform a call as the next instruction after a lxi
sp instruction.  Its not really clear which the problem is.  I
am assuming the problem relates to following a lxi sp
instruction immediatly with a call instruction, I can see how
pipelining instructions could cause this failure.   I cant
immagine how calling the address which happens to match the sp
would be an issue.  My thought was that most cp/m programs
either left the sp alone, and used the stack provided by cp/m,
or set up a local stack early on in th