DDT debug aid.

This is a version of DDT which can be built for a PRO 350 (as well as
for other systems). Just use @DDTBLD.CMD to prepare it and reply POS
as the operating system. It can do symbolic multilanguage debugs, and
(unlike the DEC F77 debugger) can debug I and D space tasks on 11/73
type machines when they are available. The normal build procedure
will allow the $1UK command (where $ means ESCAPE, coded in by control-[
on the PRO) to peek into kernel instruction space. (It can also do
on the fly searching or patching of the exec or anything else).
	This is probably the most powerful generally available debugger
for the P/OS environment, not excepting the DEC product. The beginning
of the DDT22.MAC source contains the documentation (and extra copies
were not put here, to save room.) It should let you do MORE than
almost any other debugger, with any source language you like.
	Note the old FDT modified version from [312,*] on RSX SIG
tapes can generate symbolic references to F77 or F4P programs for use
with DDT. Like the F77 debug, macro disassembly is available built in.
This debugger also knows 16 and 32 bit integers, and floating point
formats. Link your applications with DDTKNL/DA (i.e., DDTKNL is the
debug aid) and have DDT22M.TSK running as a task named DDT22M to
use the 2 task debug mode (it'l; need an $G ($ is escape, keyed as
control [) to start DDT22M, then you can proceed). Then run your 
application linked with DDTKNL and you can debug once you use the
$UM command in the debugger to point it into the target task.
DDT can even debug several tasks at once.
	Testing has not been extensive on P/OS of this debugger,
but it is well tested in M, M+, and IAS realtime flavors. The
DDT code has not been altered, but the build file has, so you have
here a complete kit. It also will provide you an I/O page common
you can link other nonprivileged code to, permitting access anywhere
needed once you learn how to manipulate the PDP11 APRs.
Enjoy!
		Glenn Everhart
