HTC, again proving that they are undoubtedly the people‘s handset manufacturer, has released their own HTC Touch Diamond ROM that flips the switch on the dormant 850Mhz GSM radio lying underneath that slick, VGA touchscreen. 
Following on the cooked ROM from xda-developers that allowed formerly tri-band HTC Touch Diamond handsets to roam free on the 850Mhz and 1900Mhz bands that the US loves to use, HTC has released it an official ROM that should turn all HTC Touch Diamonds out in the wild in to true globe-trotting, quad-band (850/900/1800/1900Mhz) GSM world-phones.
HTC says that the new HTC Touch Diamond ROM not only enables support for the 850Mhz frequency band that is so good at penetrating buildings and walls in the US, but it also improves EDGE data functions. It’s always good to be surfing EDGE on the 850Mhz band, and HTC has made sure that the new HTC Diamond ROM lets its customers do just that.
Unfortunately, there isn’t any more hidden hardware to exploit in the HTC Touch Diamond. Without 850/1900Mhz WCDMA radios under the hood, the currently available fleet of HTC Touch Diamonds aren’t going to be surfing the 3G airwaves in the US. But, as soon as HTC launches their US-spec HTC Touch Diamond for US-consumption, you can bet your non-VGA handset that we’ll be using one of our very own to surf AT&T’s HSPA network.
Head on over to HTC’s website to download the new HTC Touch Diamond 850Mhz ROM. Just remember, you’re flashing your hardware at your own risk – and remember to back up your data before you take the plunge.