Actually I may have mis-interpretted that write command. That may be for ram, and so im not sure how to the save on power off is implemented. I can see it could be built in to hardware, and if its not a native function of the chip I assume it would be but I have not seen the schematics.
I think some of the topwin programmers can do it, or I can find some other chinese ones that can, but I dont know where to get them
Ive got a topwin 2004 and it doesnt have 24c44 but has 24c32 and 24c64.
I remember a member dec head had a post about how he was reading/hacking these speedo units about a year ago .
Does anyone know what happened to dec_ head ,he used to post all the time and then dissapeared.
yeh it was definatly in the 300,000km range last time i fired it up, yep it was working last time i used it, though i flogged the lcd driver board off it to fix another trip unit so i havn't had it powered up since. im happy to post this chip in an envelope to someone who can read it. As long as i get it back at some point. Or what pic/avr would i need to buy, if there not much i might get one to play with.
Grab an arduino and have a play, will be able to have it read the data really easily. Would be good to read it, run it for a few kms and compare so the checksum can be worked out too.