[Coco] Simple coco 2 memory test?

[Robert Gault]

Eric Keppel wrote:
> Hi all,
>
>   I have made progress with my Coco2 here, and just upgraded it to 64k.
> Managed to get GLOVE running using all 64K as well as other games that
> wouldn't run before in 16k, so that is progress. :)
>
> However, I suspect that I may have a bad ram chip, since I can't get
> some things to work reliably.

Just because you have not made Drivewire3 work is not reason to suspect that you have bad 
RAM chips.

>
>   For instance, I loaded HDRDOS from the .WAV file included in the
> Drivewire package, and when I typed "DOS" to load Nitros-9 it only very
> rarely (1 in 20 times, perhaps) was able to boot all the way to an OS9
> prompt via Drivewire 3 or Drivewire 4.

Let's make sure you are CLOADMing the correct file. :) The are two files in the .zip 
archive for the Coco2 that are wave files: dw3doscc2.wav, hdbcc2.wav.
I believe the first will boot OS-9 from Drivewire3 if you don't have an HDBDOS ROM 
installed. The second should load HDBDOS into memory from tape.
Based on the binary for the first file, you must EXEC after the CLOADM to get the program 
to work. I'm not sure about the second program but if you don't have the Coco auto-boot 
into HDBDOS after the CLOADM, then it likely requires an EXEC.

  I tried both versions, hoping one
> would make a difference.  Whenever I do manage to boot fully, the
> machine will lock up sometime shortly after and not respond to commands
> anymore.
>
>   This is a home-made serial cable, so perhaps that is the issue.  I did
> notice CRC errors in the Drivewire logs (error 243 IIRC).  But wouldn't
> I get the same errors if the data is corrupted due to a bad RAM chip and
> thus verifies incorrectly?

Drivewire logs indicate that what was sent/received was corrupted. They may or may not 
indicate whether there was a match with Coco memory.

>
>   Anyway, the bottom line is that I am looking for a small memory test
> program I can run to see if it is working reliably.  Does such a program
> exist, and if so, can someone direct me to it?
>
> Thanks!
>
> --Eric

Do you want source code, a binary, a binary on a .dsk image, or a .wav file?