Thanks

[Ken]

they are checksum checked if the program id for example on vs is 51, if it is AA it will bypass the checksum check. The enhanced xdf will correctly update the checksum if you want to leave this working.

I had a quick glance at some of the 128kb bins tonight after dinner, & noticed they appear to follow a 4096 byte section size, the 1st of which starts at hex2000,8kb mark, & by 2008 has the program ID
in it you mention above.
So now I'm wondering if the checksum is calculated over the entire file, or just the 1st section like a computer bios, (although the 1st section in a bios is a compressed module).
I know it's an irrelevant question that probably doesn't interest anyone, just I like knowing more about the internal workings.
Has anyone worked out where the checksum is stored yet.

[VL400]

It covers the entire program/bin. It only skips a few bytes in the calc, the checksum bytes being 2 of them! Check sum is at address 0x2006, the checksum calc starts from 0x2008.

[Ken]

It covers the entire program/bin. It only skips a few bytes in the calc, the checksum bytes being 2 of them! Check sum is at address 0x2006, the checksum calc starts from 0x2008.

Thanks a lot for divulging those facts, greatly appreciated..

Edit: seems a similar rule for fixing the checksum applies to all the Delco roms, with the 64kb versions being a little trickier, having to check the crc from either 4 or 8kb before the Hex6006 mark,
depending on where the section before the Hex6000 point starts, I noticed the VX-Y's are sometimes different too..
After doing a search on the forum, I see the topic of CRCs has been brought up before this thread, & that people seem to know how to fix it, but choose to use a method to eliminate the check,
& that the modded binaries hosted here in various threads haven't had their checksums updated.
Another thing I found when testing the method of manually updating / checking checksums, was that there's a collection of Delco roms getting about, & the "VYV6\$060 LPG\92162169.BIN" is
31 bytes short of the full binary.

Ken, i have a brand new spare USB Datalogging adaptor from VL400 if you would like one shipped closer.

I forgot to thank you for this offer.
Thanks..

[Ken]

When I 1st started this thread, I bought the nvram, obd plug & usb lead from VL400, & intended on playing around with the 95 VS sedan my son had owned at that time, long story short, he totalled the car before I got around to really doing anything with it...

I've since steered a few other friends over here to purchase the gear required to do their own cars, & get asked questions about setting up the plugin & settings, & figured since my son has bought another VS, I'd re-freshen my memory of the setup & workings of the tuner pro app...

Was wondering whether the nvram I bought off VL400 would need a different binary on it before starting..
His old VS V6 was a BRHR6556 chipped cop car with a T5, this one's a later 98 Getrag with the BZPT chip...

Weekend just gone I plugged the nvram into the sons pcm, loaded tunerpro on the old P4 laptop I had spare, configured the latest OSE plugin & chose new the port that appeared
once the plugin was loaded, started tunerpro & hit the left/right arrow (aquire data) button & connected straight away, however, the [ DA: Connected ] sign on the bottom of
tunerpro flashed from green to red then back to green, & stated disconnected a few times for barely half a second, in the minute or so I was connected & running tunerpro...
I changed usb ports, disconnected & reseated the nvram & the obd plug & cable more than once, nothing changed though..
Is that normal to see that split second disconnect occurring when in use..

[delcowizzid]

Will most likely be the cable echo setting causing bad connection and jumping data

[antus]

In a vs the security ok request and response goes across the ALDL bus too and the adx doesnt expect it. If the echo setting doesnt fix it properly and if you clicking connect straight after key on try waiting a few seconds to let the car security do its thing before you start logging.