The Powershot ELPH 330 HS (IXUS 255 HS in Europe) was released on Jan 2013
An alpha release of CHDK is available for firmware version 1.00F from this forum thread.
Reviews and Specifications
The use of ver.req to determine your firmware version does not work. It is recommended you use the ACID utility to determine your firmware version.
#define GREEN_LED 0xC022C020 #define AF_LED 0xC022C028
Download location for firmware dumps: