Application Processor (OS Chip): S5L8720
The name used in firmware is iPod2,1.
See the S5L8720 (Hardware) for hardware details
0x1227 = DFU Mode 2.0 (Basically WTF 2.0 burned into bootrom)
0x1293 = Normal Mode (comm with iTunes / MobileDev framework)
See the S5L8720 page for all known exploits