dbug wierdness

[Glenn Roberts]

I’m seeing something odd using the HDOS debugger (DBUG) – something I haven’t played with in a long time!  I found whenever I set a breakpoint the program counter is always set to 377356 after the breakpoint (instead of whatever address the break was set for). To reduce the problem to simplest form I typed in the short assembly program used in the manual and booted from a generic HDOS 2 disk (via the H17) and followed the breakpoint example on page 3-15 in the HDOS software reference manual:

 

:B:BKPT 70015/6

:B:GO 70000

 

After the breakpoint is hit I should see:

-P=070015-

 

But instead what I see is:

 

-P=377356-

 

So the breakpointing feature is worthless until I figure this out.

 

I have the luxury of having a second working H8 system (my original “plain jane” 8080 system with three 16k static RAM boards from 1980).  When I boot and run from the exact same disks on that system IT WORKS CORRECTLY.

 

The system where I’m seeing the problem has the Heathkit Z80 CPU board (HA8-6) and DRAM board (WH8-64).  It also has both soft (’37) and hard (’17) controller cards (the problem is there no matter how I boot).

 

So my best guess is this is a bug that shows up on Z80 systems.  Is so I’m guessing there was probably something in REMark that said how to patch it to get it to work.  Before I start digging out my old mag’s does this ring a bell for anyone?...   is there a better debugger somewhere in the HUG files?..  (for HDOS that is, not CP/M)

 

Thanks!

-          Glenn

 

(p.s. I’m using this to try and track down some of the bugs in the H67 PART utility – the one we’ve been using can’t be re-run after it’s been run once).

 

[Kenneth L. Owen]

Hi Glenn,

My H-89 is running a Z80. I run the test and let you know if it works
or not. May not fix your problem, but will tell us if it is because of
the Z80 CPU.

I also have a Z80 board in my H8, so I do the test there as well.

-- ken

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[Kenneth L. Owen]

Hi Glenn,

Ran the test on the H-89 and it works just like the manual says. So,
that would say that it is not a Z80 issue per se. I'll fire up the H8
with the Z80 CPU card tomorrow and see what it does. I'll post when I
get results.

-- ken

[Glenn Roberts]

Thanks.

-----Original Message-----
From: se...@googlegroups.com [mailto:se...@googlegroups.com] On Behalf Of
Kenneth L. Owen
Sent: Thursday, February 02, 2012 10:26 PM
To: se...@googlegroups.com
Subject: Re: [sebhc] dbug wierdness

Hi Glenn,

Ran the test on the H-89 and it works just like the manual says. So, that
would say that it is not a Z80 issue per se. I'll fire up the H8 with the
Z80 CPU card tomorrow and see what it does. I'll post when I get results.

-- ken

On Thu, 2012-02-02 at 21:44 -0500, Kenneth L. Owen wrote:
> Hi Glenn,
>
> My H-89 is running a Z80. I run the test and let you know if it works
> or not. May not fix your problem, but will tell us if it is because
> of the Z80 CPU.
>
> I also have a Z80 board in my H8, so I do the test there as well.
>
> -- ken
>
>
> On Thu, 2012-02-02 at 20:44 -0500, Glenn Roberts wrote:

> > I'm seeing something odd using the HDOS debugger (DBUG) - something

> > H67 PART utility - the one we've been using can't be re-run after

> > it's been run once).
> >
> >
> >
> >
> > --
> > You received this message because you are subscribed to the Google
> > Groups "SEBHC" group.
> > To post to this group, send email to se...@googlegroups.com.
> > To unsubscribe from this group, send email to sebhc
> > +unsub...@googlegroups.com.
> > For more options, visit this group at
> > http://groups.google.com/group/sebhc?hl=en.
>
>

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[Kenneth L. Owen]

Hi Glenn,

I ran the Break-Point test on the H8 running Les' Z80 card and H17
controller only. The break-pointing worked properly.

-- ken

[Norberto Collado]

Perhaps the DRAM board is not working as expected (marginal)???? Do you have Les 64K Static memory board to try out? 

 

 

Norberto

[Glenn Roberts]

Thanks guys. I’ll have to do more experimentation to see if I can isolate the problem.