Newsgroups: comp.os.msdos.programmer
Path: utzoo!utgpu!watserv1!maytag!watstat!dmurdoch
From: dmurdoch@watstat.uwaterloo.ca (Duncan Murdoch)
Subject: Re: Good debugger for DOS?
Message-ID: <1990Aug9.174711.21884@maytag.waterloo.edu>
Sender: daemon@maytag.waterloo.edu (Admin)
Organization: University of Waterloo
References: <9611@goofy.Apple.COM> <10210006@hpspcoi.HP.COM>
Date: Thu, 9 Aug 90 17:47:11 GMT
Lines: 21

In article <10210006@hpspcoi.HP.COM> dlow@hpspcoi.HP.COM (Danny Low) writes:
>>Is there a good low-level debugger for DOS machines that will take over
>>the system when it crashes?
>
>There are ICE machines for Intel based PCs. Intel makes them as
>does Hewlett Packard. The HP 64000
>will support all Intel processers (except the 486) up to 25MHZ. There are
>also PC hardware debugging boards that snoop the SPU. The Atran Probe is one
>that comes to mind. If you are willing to pay the money there are some
>very good low-level debuggers for DOS machines that are just what you
>are looking for.

If you're on a really tight budget, it might be enough to install an NMI
breakout switch.  The current issue of PC Techniques gives details; all
it involves is connecting a normally open momentary contact switch from 
one of the bus lines (A1, I think, but don't trust my memory!) to ground.
With a debugger like Borland's Turbo Debugger fielding NMI interrupts,
this might let you break out of an infinite loop even with interrupts 
disabled.

Duncan Murdoch