[Coco] Need some tips debugging 6309 for OVCC

[Walter Zambotti]

Ok

I need someone with a real 6309 to confirm what happens when one of tfm instructions is called with an initial starting value of W = zero.

Does it do:

1. nothing or ...
2. transfer 65536 bytes

My implementation will do the later but the manual isn't specific.

It can be done in two ways:

1. The test for zero followed by the decrement
2. The decrement first followed by the test for zero

The former will move a maximum of 65535 bytes if W = &HFFFF.

The later will move a maximum of 65536 bytes if W = 0.

Both will move same number of bytes if W is not equal to zero.

Regards

Walter

-----Original Message-----
From: Walter Zambotti [mailto:zambotti at iinet.net.au] 
Sent: Wednesday, 4 December 2019 11:11 AM
To: 'CoCoList for Color Computer Enthusiasts' <coco at maltedmedia.com>
Subject: RE: [Coco] Need some tips debugging 6309 for OVCC

Robert

EOU Ease Of Use (Nitros9).

Mesa - I should have said MAME (Mess)!

Walter

-----Original Message-----
From: Coco [mailto:coco-bounces at maltedmedia.com] On Behalf Of Robert Gault
Sent: Wednesday, 4 December 2019 9:17 AM
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
Subject: Re: [Coco] Need some tips debugging 6309 for OVCC






Walter,

What did you mean by EOU and MESA? Are they typos for EQU and MESS?

There is no 6309 code in NitrOS-9 Merge nor does there seem to be any special use of the stack that might cause problems going from 6809 to 6309 code.

One way to use the debug/trace facility in MESS/MAME to trouble shoot this problem might be to assemble a special version of Merge with a continuous loop loop bra loop so you can in debug mode you can step over the loop and see how Merge is failing.

Robert

 On Tuesday, December 3, 2019, 7:01:26 PM EST, Walter Zambotti <zambotti at iinet.net.au> wrote:


 Curtis

It manages to boot completely and setup 3 other windows.  It even creates the vterm window successfully.  The only thing causing the crash is the merge command that is loading the fonts.

I would assume this would cause the graphics driver to kick into gear.  So if I avoid any graphics I seem to be ok.

I've even run basic09 (6309) and tried some simple division and multiplication math. Seems ok!

I have now looked at MAME 6309 code and it is basically an abstraction layer to a general purpose device emulator within MAME. There is no chance of extracting the 6309 cpu component and running it independently of MAME.

So I will not be able to compare the MAME 6309 cpu to the VCC or OVCC 6309 cpu.

I now have to identify the culprit instructions!

Walter


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