Abstract: An image data flow control and storage facility having a secondary storage, a secondary storage controller, an image input controller, an image output controller and an optional loop-back controller. According to one embodiment, the image input controller, the image output controller and the loop-back controller communicate with the secondary storage controller by way of a PCI-type bus. The secondary storage controller communicates with the secondary storage by way of an SCSI interface. Preferably, the secondary storage controller operates in master mode to transfer blocks of image data directly between the secondary storage and the image output, image input and loop-back controllers. By performing direct image data transfers, the facility of the invention avoids intermediately storing image data in costly DRAM page buffers.