Product name:Sanguinololu V1.3AProduct Features· Supports multiple communication configurations.· Supports multiple power configurations· Small design - board is 100mm x 50mm (4" x 2") - barely an inch longer than a business        card!· Sanguino clone, Atmel's ATmega644P - ATmega1284 drop-in compatible!Product DescriptionSanguinololu is a low-cost all-in-one electronics solution for Reprap and other CNC devices. It features an onboard Sanguino clone using the ATMEGA644P though a ATMEGA1284 is easily dropped in. Its four axes are powered by Pololu pin compatible stepper drivers. The board features a developer friendly expansion port supporting I2C, SPI, UART, as well as a few ADC pins. All 14 expansion pins can be used as GPIO as well. Version 1.3a has no software changes - the pin assignments remain the same and your 1.2+ compatible firmware should work here fine. The hardware changes: -- Removed the Molex HDD connector in favor of using the voltage regulator - some power supplies give a dirty 5V signal when there is no motherboard load, so its better to just use the power supply's ATX+4 connector and the 5V voltage regulator. -- Added a jumper to enable/disable USB auto-reset. This way if you're printing from an SD card using SDSL you can disconnect your USB and reconnect it without interrupting a print. -- R7 and R8 are now 100k pull-up resistors that are on the stepper-enable lines. This ensures the stepper motors stay disabled and don't move while uploading new firmware, rebooting, etc. The current limiting resistors for the FTDI are gone. -- There is an extra Z-motor header for Prusa Mendel. Package List: 1 x Controller board Sanguinololu V1.3a