pcmhacking.net

yeh i didn't think it'd read properly, ive search all over Willem stuff but can't find anyone trying to read these, ill see how we go when i get that ebay programmer, prob that same as that circuit you posted above

ok got the programmer today, didn't come with anything, so not sure what software to use with it, i did a quick google and found ponyprog and tried reading it with x2444 but not having any luck, ill post some pics of the board later, it does have a input jack for a power supply but wouldn't need it for this chip? Not for reading anyway. The board has http://www.nbglin.com written on it. I havn't used this ponyprog before but it seems to connect ok just can't get a read. Any Idea's?

here's the programmer. i have it all correct?

Might need to make an adapter, looking at the PCB pins 1-4 are all grounded which is fine for a normal 24cxx EEPROM. The 24c44 pinout is not the same so the I2C interface is on the wrong pins.

Are you sure the ic isnt in the zif ass about or up the wrong end ?
Normally the pin 1 indentation doesnt face the bottom of the zif on other ics.

it's a 3 chip setup, furtherest right socket space is for 25 chips middle is for 93 chips and left is for 24c chips. I hadn't really looked at the circuit or pinouts yet, big day and big week for me, so thanks VL400 guess ill have to figure out a adaptor, off to bed ill come back tomorrow lol

Fairly sure the ebay ad said x24c44 via ICSP only, so you can't use the ZIF socket.
Yesterday I started putting together a bit banged pic to read/write these, but need to check it out with a scope because I'm not getting anything on the MISO line, but the data appears to be clocked in according to the datasheet.
It's probably something stupid like a broken pin on the nvram knowing my luck - or CE is really active low....

Just saw your latest post - they're roughly pin compatible with 93c eeproms (reversed microwire pinout?) but pin 6 and 7 need to be pulled high.
On a 93cxx, those pins are NC and ORG from memory?

festy wrote: Yesterday I started putting together a bit banged pic to read/write these, but need to check it out with a scope because I'm not getting anything on the MISO line, but the data appears to be clocked in according to the datasheet.
It's probably something stupid like a broken pin on the nvram knowing my luck - or CE is really active low....

Using my sound card as a crude 'scope, it was pretty obvious my clk pulses weren't up to scratch so a slight change to the code and I'm getting data out of it now. It really is a square wave, but the damn AGC on the microphone line makes it look rather strange as it tries to average it out

Now to finish the code to read 16 bit words, and see if I can get a reasonable looking dump out of this thing...

Close, but not quite there it seems...

I read this off a VP dash just then: which is decimal for: Now all the checksums appear to check out - but this dash's odo shows 343479kms, which should be C2 C2 E9.
Maybe I'm not catching the first bit on a read or something, but I would have expected garbage checksums in that case?

Edit: reading the nvram as 32x8 instead of 16x16 still produces the same data, so I don't think I'm missing the first bit on a read

Which model car is that chip from?