Date   : Wed, 06 Oct 1982 16:18:02 EST (Wednesday)
From   : Cal Thixton <tj@Okc-Unix>
Subject: Re: Problem using DDT

DDT, as I recall, uses a rst instruction to return control back
to itself when a break is encountered. I have seen that a few
CP/M systems like to use some locations in base page that perhaps
it shouldn't. It may be that this is where the hangup is at. if
a break is encountered, a rst x instruction gets run which causes
a jump to 0000 0000 00xx x000. if the instruction there is trash,
then anything can happen

cal