Abstract: An adapter program couples a legacy operating system to a driver program of an I/O channel which has an incompatible interface to a native operating system. The adapter program includes a translator which receives legacy control structures from the legacy operating system that represents a legacy I/O instruction. The adapter program also includes an interface to the driver program which simulates the native operating system interface. The adapter program further includes an emulator for performing the I/O instruction by interacting with the driver program thru the simulated native operating system interface.

Abstract: An adapter program couples a legacy operating system to a driver program of an I/O channel which has an incompatible interface to a native operating system. The adapter program includes a translator which receives legacy control structures from the legacy operating system that represents a legacy I/O instruction. The adapter program also includes an interface to the driver program which simulates the native operating system interface. The adapter program further includes an emulator for performing the I/O instruction by interacting with the driver program thru the simulated native operating system interface.

Abstract: A stream of data words is sent from a memory thru a controller and an external data buffer to an I/O device by a method which includes the steps of: 1) transferring a segment of the stream of data from the memory into the controller while concurrently sending a subsegment of the segment from the controller thru the data buffer to the I/O device via a transmission burst in which the receipt of individual parts of the subsegment are not acknowledged by the I/O device; 2) receiving a signal in the controller from the I/O device at any time during the sending step, to terminate the transmission burst; 3) subsequently receiving a signal in the controller, from the I/O device, to restart the transmission burst beginning with a selectable part of the last subsegment that was sent; 4) removing from the controller, only the portion of the segment which precedes the selectable part of the subsegment; and, 5) repeating the above steps until the stream of data is received in its entirety by the I/O device.