ZX-40 versus the BX-35

Discussion specific to the DIP and TQFP packaged ZX devices like the ZX-40, ZX-44, ZX-32 and ZX-328 series. The differences between these devices is primarily the packaging and pinout so most issues will apply to all devices.
dkinzer
Site Admin
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Joined: 03 September 2005, 13:53 PM
Location: Portland, OR

Post by dkinzer »

To solve the immediate problem, I'll have a v1.2 ZX-40 sent out on Monday. The next step will be for us to modify a BXDS here and try the downloading/updating with a ZX-40 in place. Depending on the results of that experiment, we may have other things for you to look at or try out.
- Don Kinzer
drapal
Posts: 25
Joined: 24 January 2006, 8:07 AM
Location: Denver

Post by drapal »

Thanks. I'll also spend some time this weekend finishing the end product board (I'm using the SIMM100 board from Dontronics). I have one mostly soldered up and it shouldn't take me too long to finish it. This would prove that the BXDS has something going on, and maybe from there I can help isolate it.

BTW, I tried a totally different system last night for both of thes upgrade attempts (my laptop from work). The upgrades failed the same way, so the issue is definitely on the BXDS somewhere. The most probable culprit is the ATN circuitry, esp. since this is where the modifications are.
drapal
Posts: 25
Joined: 24 January 2006, 8:07 AM
Location: Denver

Success!

Post by drapal »

First off, thanks for all of the support. As it turns out, the problem was very simple (once I figured it out :oops: ).

I found the source for ZLoad in the install directory, so I decided to use Visual Studio to debug it. It turned out that the crash was a stack corruption in update(), and looking at the code, the only way I saw that this would be possible is if the recbuf had been overrun. The comment says that the input file is assumed to be OK, so I went to validate that assumption, and found out that indeed the input file was incorrect.

How did it get that way? When I downloaded it (clicked on the link), the file was opened in IE (rather than getting the file download alert). No big deal, just Save As... from IE and everything will be OK. Well, that's not exactly true. If you do that, IE wraps the first line (since it is very long) onto the second line, thus corrupting the file.

Long story: I now have a V1.2 ZX-40, and the download of the test program worked fine. :D
dkinzer
Site Admin
Posts: 3120
Joined: 03 September 2005, 13:53 PM
Location: Portland, OR

Post by dkinzer »

Thanks for the superb diagnosis. I'll look into ways to protect against the buffer overrun that you discovered. Thanks for the update.
- Don Kinzer
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