Working on a 93C66 eprom. I am a electronics tech and have not had much experience with programming code. I have read the eprom but can not find the information I am looking for in the hex code. Forklift/heavy equipment application. There are only 000 - 0F0 lines so there is not much to it. Appreciate any help.

 

What information are you looking for?
Can you please elaborate a bit more?

 

I am attempting to reset a digital hour meter, which may or may not be stored in this particular chip (there is also a H8S-2692 processor that I have not yet touched). They rebuild the motors for the front loaders and I am working on the dash. I know what the hours are on the display. I have read the chip and viewed the code in the buffer. Different hex converters give me different outputs. Thats where I get confused. I have ten years experience troubleshooting, reverse engineering, and repairing automotive circuit boards. I have limited experience programming eproms, but I am learning when time permits. With that being said I am unable to locate hex code in the chip because I am not sure what I am looking for.

 

Can you take and post a photo of the circuit board?

 

OK, if I get you your company is rebuilding the motor so you need to reset the engine hours counter.

F0 lines is 240 lines to check. Hope you have a computer to search it for you!

Can you run this system any to score some more engine hours? If you can, record what is in the ROM, run it till the display shows a change, stop and read the ROM again. Compare the files, and if there is a change that may be the hours.

If you see that, stop by and tell us what you saw (original rom & displayed hours, then the new readings).

I would suspect it stores something better then hours: if I run the thing for 10 minutes 6 times it should show 1 hour of run time, right?

 

Here is the 93C56 on the back and the processor on the front. There are two other chips, one is an 8 pin CAN interface, and the other is 16 pin chip that is not involved in the memory.

 

That looks almost exactly like the technology used to reset the stored odometer count in car dash (speedos) which is illegal in just about every country and also might conflict with forum rules regarding vehicle modification.

 

Have you tried contacting the manufacturer of this machine to see what their official methods are for resetting hours?

What is the board or component model? Forklift model, year of manufacture?

Random blurry pictures don't really help.