Scheduling multiple disk requests and writing data buffers to disk

An electronic image processing system comprising an electronic scanner and an electronic printer for forming an image, a controller for directing operation of the image processing means, the controller including a mass memory device for storing data to be printed, random access memory, a printer control, and a Resource Manager, the random access memory interconnected between the printer control and the mass memory device, the Resource Manager ensuring access to the random access memory for conveying data from the mass memory device to the printer via the random access memory, the Resource Manager including a mass memory device scheduler to provide printer access to the random access memory, the mass memory device scheduler having reservation means to reserve mass memory device access at predetermined times and means to determine that access to the mass memory device is invalid within a given time.

In an electronic image processing apparatus having image processing means including a plurality of resources for forming an image, a controller for directing operation of the image processing means, the controller including a mass memory device and a random access memory, and a Resource Manager, the method of ensuring access to the random access memory for conveying data from the mass memory device to at least one of the plurality of resources via the random access memory comprising the steps of:

• requesting from the Resource Manager guaranteed times for transferring data from the mass memory device to the random access memory, and
• providing a reservation queue by the Resource Manager allowing said one of the plurality of resources to schedule predetermined mass memory read operations to be completed at predetermined different times.

In a printer having random access memory RAM, a mass memory device and a mass memory access queue, a method of guaranteeing access to the mass memory device via RAM comprising the steps of:

• requesting predetermined mass memory device bandwidth,
• monitoring RAM space to determine if suitable RAM space is available to access said memory device bandwidth,
• selecting the request for said memory device bandwidth in a mass memory device request queue if suitable RAM space is not available, and transferring the request for said mass memory device bandwidth to the mass memory access queue when suitable RAM space is available.