Date   : Thu, 12 Sep 1985 22:25:56 GMT
From   : Jeff Woolsey <woolsey%umn-cs.uucp@BRL.ARPA>
Subject: Re: Z8E - at last! a free Z80 debugger for CP/M

OK, I've tried to get Z8E running on my machine (I mean I'm real tired of DDT),
but the developers of Z8E forgot one thing:  Z80s have something called
interrupt mode 1.  This is the quick and dirty interrupt mode which causes
a jump to 38H.  Z8E (and unpatched versions of DDT) use restart 7 (which
also jumps to 38H) as the breakpoint mechanism, which on my system (and 
presumably others, since Digital Research issued a patch for DDT to use a 
different restart vector) is the address of the interrupt handler.  No good.

I tried to change which restart vector it uses in the source, but there aren't
any wonderful equates at the front of the source that would make this easy, so
I had to go digging.  I may have gotten them all, after a single pass through
the source, but somehow I doubt it, as the program now crashes after I ask
it to disassemble four instructions.  Real useful.   HELP!

-- 
-- 
Even the ghosts will have settled down and raised families by now.

                               Jeff Woolsey
                               ...ihnp4{!stolaf}!umn-cs!woolsey
                               woolsey@umn-cs.csnet