Errors in Hex files. Can U Help

[stoker]

Yes, another beginner. Bought 2 Hex. files, one for 16c54 and one for 16c55. Both show a "checksum error line 65"
I have used a "decompiler/disassembler" to get to a machine code listing, but that sort of leaves me cold too. Using MPLAB programme, the 16c54 will run in debug, but not correctly, the other one for the 16c55 fails all in MPLab.

I am a total novice, still trying to learn the codes etc. So my request to anyone with the experience, can you offer to help out. I am totally lost with this lot. The seller isnt interested in helping out at all.

Many thanks.
stoker

 

[Wp100]

Hi,

Perhaps I'm missing some point here, but buying the .hex code for a one time programable near obselete chip does not make much sense.

You say you are running it in Mplab with debug - but how / which debugger - do you have the source code as well ?

Disassembling the code leaves most people cold - its of little use like that, unless you are very clever.

Perhaps if you gave us some idea of what the programs are and do, then we can help you do things the right way round.

 

[dougy83]

Provided that the hex files are not copyright, you can post them here for someone to fix. Or just post line 65 and we can likely tell you what it should be.

 

[stoker]

16c54 and 16c55 hex problems.

Possibly you are missing something, that is why I let all know that I am a starter. Bought the hex code a while ago, and havent got to it for a while. I am starting to teach myself PIC, using these two programmes. I hope to change the 16c54 for a 16F54 if all goes well. Yes, in MPLAB I am using the debug programme, again I restate that I am learning so if I am not able to use this MPLAB properly then I will improve, hopefully.
I have the copies of the source code from the disassembler and I can see that there is a problem towards the end of each programme (checksum error in line 65 - as listed in hex file)
I know it is hard to advice someone over the net, all I am after is someone to point me in the right direction and possibly help out.

Hi,

Perhaps I'm missing some point here, but buying the .hex code for a one time programable near obselete chip does not make much sense.

You say you are running it in Mplab with debug - but how / which debugger - do you have the source code as well ?

Disassembling the code leaves most people cold - its of little use like that, unless you are very clever.

Perhaps if you gave us some idea of what the programs are and do, then we can help you do things the right way round.

 

[stoker]

Hex erors.

Thanks for the constructive advice, will do what you suggest and Im sure that will help a lot
Thanks again.

Provided that the hex files are not copyright, you can post them here for someone to fix. Or just post line 65 and we can likely tell you what it should be.

 

[stoker]

Hex Errors on PIC16c54 and 16c55

Here are the lines with the Checksum errors as listed from the Hex files.

16C54, :1003F000 FF0F FF0F FF0F FF0F FF0F FF0F FF0F 5C0A 35 - Line before Error
16C54, :08040000 0F00 0F00 0F00 0F00 BE - Error Line
16C54, :021FFE00 F50F DD - Line after Error.


16c55, :1003F000 C00C 3200 3300 1505 5505 E605 170A EF0B 52 - Line before Error
16C55, :08040000 0F00 0F00 0F00 0F00 BE - Error Line.
16C55, :021FFE00 F50F DD - Line after Error

 

[Sceadwian]

If it's a checksum error that means the data in that section of the hex could be corrupted. There's no way to fix it really without knowing what the code should be, trying to determine what's wrong by looking at the disassembled code would be a pain. De-ASM'd code is a nightmare to decode, almost harder than completely re-writing the code.

You could try posting what the code 5 lines above including and bellow the errors that your disassembler program generates, there may be something obvious that someone would see, the hex code itself is pretty useless.

 

[dougy83]

The checksums (last 2 characters on the line) should be B8 instead of BE for those 2 lines according to my calculations. See Intel HEX - Wikipedia, the free encyclopedia for info on how to calculate them yourself.

 

[dougy83]

Actually, you might get away with just ripping out the offending line; it looks like it could be the ID locations (address 0x200-0x203 (in words I guess - that's why the hex file says address 0x400 (in bytes I'm guessing again))). Either way, it shouldn't cause too much problem.

 

[Sceadwian]

If they were irrelevant then why did one run in mplab but not correctly and the other one not run at all?

 

[dougy83]

If they were irrelevant then why did one run in mplab but not correctly and the other one not run at all?

Um, possibly because the code is rubbish to start with?

 

[Sceadwian]

That's entirely possible =)

 

[3v0]

If your goal is to learn to program PIC's why are you messing with purchased hex files ?

3v0

 

[Wp100]

Hi

Bought the hex code a while ago, and havent got to it for a while. I am starting to teach myself PIC, using these two programmes. I hope to change the 16c54

You say the code is for leaning about Pics - assume it is some form a starter board program ??
The fact that its on a 16c54 tends to imply that it will be an old program anyway - perhaps not the best to use ??

As 3v0 has just said, there is loads of free learning stuff here and else where.

Looks at the Sticky entry at the top of this forum its full of beginners info and tutorials.
Try this tutorial by one of ETs own gurus, which covers software and hardware

 

[Mickster]

In addition to Wp100's suggestion of using Nigel's well tried & tested tutorials, the MPASM User Guide (linked below) is a valuable resource and is particularly useful for understanding error messages:
https://www.electro-tech-online.com/custompdfs/2010/01/33014j.pdf

 

[blueroomelectronics]

All the C series PICs except the 16C84 are one time programmable unless they have UV windows.

 

[stoker]

Hex files - help

To all those that offered help and advice I would like to thank you all, it has been very helpful for a beginner
To those who only paid out on a novice, well I hope you never make a mistake in your life.
Many thanks again to all

 

[3v0]

To all those that offered help and advice I would like to thank you all, it has been very helpful for a beginner
To those who only paid out on a novice, well I hope you never make a mistake in your life.
Many thanks again to all

Making mistakes and learning go hand in hand. Next thing you need to learn is how to take help gracefully. I can only wonder what your reaction would have been had you been criticized !

You have given us little information that would let us help you in a constructive way.

Do you know how to program in any language ?

 

[Mickster]

To all those that offered help and advice I would like to thank you all, it has been very helpful for a beginner
To those who only paid out on a novice, well I hope you never make a mistake in your life.
Many thanks again to all

TBH stoker, I don't see anywhere within this thread where 'the novice has been beaten up'....it's not really the kind of thing we tend to do on this forum.

For starters, trying to interpret a disassembly of an unkown HEX file is something which the most seasoned programmers here would likely hate to attempt, let alone suggest to a beginner.

Undocumented ASM code is pretty difficult to decipher after some time even by the person who wrote it, let alone someone else trying to follow and understand.

You'd do much better in your quest by starting from scratch, with basic tutorials designed to teach fundamentals and gradually introduce more advanced topics/methods.

A few links:
Nigel Goodwin's (Nigel Goodwin) tried and tested PIC tutorials...


David Meiklejohn's (Meikled) tutorials...
Gooligum Electronics

Pete Griffiths (Geko) PIC projects site...
Picprojects main project index page

Also searching for posts by 'Pommie', 'Mike,k8lh', 'Mr RB', 'AtomSoft' etc. will turn up some great examples, along with some very well-documented recent code from 'jakeselectronics'.

HTH to get you going.....


Regards.