[Gnif] was doing what any type of great hacker does… poking around the insides of one of his tools to see exactly how it works. While in there, he found that an EEPROM hack might make the Agilent U1241A function like the U1242A.

If you’re into this type of thing the Rigol 1052e hack ought to have already popped to mind. That was a firmware crippled gadget that, when unlocked, made the less expensive design behave the exact same methods as it’s $400 much more costly sibling. This doesn’t have rather the exact same impact, as the cost difference is somewhere between $20-$100. Still, this stuff is just cool, right?

A few messages down in the thread linked above [Gnif] shares the story of exactly how he discovered the hack. After shorting the i2c lines of the EEPROM while powering up the meter he was able to see that the gadget initializes a great deal of its values to 0xFF when it can’t discover the kept data. The next step was to utilize an STM32 board to dump the EEPROM contents. With the backup data kept safely he started altering values as well as reflashing the chip. with this process he found that changing one byte from 0x01 to 0x02 enabled the higher model’s features. It likewise works for upgrading the U1732C to the U1733C function set.