I realize this is not a DS4000 BW tread but I hope it can be viewed as close enough to investigating the DG4000 that I can ask some DS4000 things too.
The various serial decode option settings of the DS4000 can all be set by entering a code, but the BW hack is still not clear as far as I know.
So far I think there are two ways forward that looks promising.
1. HW straps (two resistors, where one is not populated) on the board for "HD Modify version" (not the "HD PCB version" bits)
2. option keys similar to the DS2000, except at least one user has reported unsuccessfully trying many of the bits apart from the ones we know activate the serial decode options.
1.
I have the 011 pattern on my DS4014 and the resistors are 10k to GND or a supply.
0 side is grounded both to metal frame and to pin 2 on the closest programming connector and to pin 13 on the one closer to the BF.
1 side is connected to pin 7 on the closest programming connector but not to any pins on the BF connector.
Very tempting to use micro clips and wire in a 1k here.
...
Well it was so tempting that I had to try it.
I did these patterns without getting any change to the major scope version in utility-system-system info: 010, 001, 111 and the original 011 of course.
I also did not see any changes in rise time but that is not conclusive due to uncertainty with the source I used.
Looking (afterwards) at the extended HW version (edge trigger mode F7 + F6 + F7 + Utility. then utility-system-system info ) it says 0.1.2.3.
This matches nicely with the straps for "HD PCB version" being 01 and 10, and the "HD Modify version" being 011.
I can verify this at a later time, did not think about the extended version screen until after put it partly together again.
This means that point 2 gets more interesting.
2. This is the part that sounds similar to the DG4000 work done in this tread ... what would be a good thing to investigate?
Sniffing the I2C for BW setting commands? (assuming for now that it is the same variable BW buffer as in DS2000)
possibly verifying by sending a higher BW setting on I2C?
extracting the BF image and search for hints of keys for BW upgrades?
search BF image for the I2C code setting the BW and back trace variables used?
I newer used the BF so I am on thin ice here when it comes to interfacing it.
Do we have a DS4000 image to look at already or do we need to get one?
I know someone that has recently worked on BF designs so I can borrow a programming pod from him if needed.