A device has processing hardware to carry out a blood processing procedure. A processing control manager resides on the device to monitor status conditions over time during the blood processing procedure. A data interface also resides on the device. The data interface includes a flash memory data storage medium formatted to allocate discrete block file spaces to receive data. Chronologic data or time-specific data are created based upon sensed conditions by a data generator task, which also resides on the device. A file manager task appends chronologic data to an allocated file space to create a chronologic block file, which, when read, provides a time-ordered account of processing activities or hardware conditions. The file manager also operates to block-write time-specific data to another allocated file space, which, when read, creates a snap-shot of processing conditions at a given point in time. The data file structure created on the flash memory medium withstands corruption of data due to power failure.