Abstract: A method of remote debugging comprises a first computer system that communicates with a second computer using a network connection. The first computer system controls the remote debugging and comprises a first operating system. The second computer system comprises a second operating system and software being tested. User input, in the form of debug commands, is received using a remote debugger in the first computer system to control the remote debugging session. The remote debugger translates a debug command into messages that are sent from the first computer system to the second computer system. The messages correspond to tasks that the target computer system performs to complete the debug command. During debugging, the target computer system transitions between polling or stopped mode and interrupt-driven mode by transitioning both the target operating system and network hardware in the target computer system that interfaces with the network.

Abstract: A method and apparatus for operating a computer graphics system to perform a conditional test on a node in a graphics data structure during the traversal of the graphics data structure by a structure walker. The graphics system is operated to manipulate data contained in a memory to define a value for an operand that is to be tested. The system accesses the operand from the memory. A structure walker performs a test on the value of the operand during traversal of the graphics data structure. Depending upon the result of the test, the structure walker traverses one of several paths in the graphics data structure to create a graphics display.

Abstract: A stand-alone graphics workstation including a digital computer host and a graphics processing subsystem is disclosed. Address data relating to the graphics subsystem components is mapped into the host system virtual memory. The application processes residing in the host are thereby able to communicate directly with the graphics subsystem components, as, e.g. the structure memory, without the need of a direct memory access hardware arrangement or device drivers.

Abstract: A method for operating a computer graphics system to build custom nodes containing commands and data information that is stored in a data structure in the graphics subsystem. A host processor calls routines which build the custome nodes. A structure walker traverses the data structure and extracts the information from the data structure to pass it to the graphics subsystem for display. The use of custom nodes increases the flexibility of advanced graphics data structures bny allowing the creation of other data structures during execution of a first data structure.

Abstract: A host system executes one or more application programs which results in graphic data structures. These graphic data structures are then continuously and asynchronously traversed. Traversal requests by competing application programs are scheduled and performed so that each application views the graphics processing as its own. The traversal and ordering of traversal requests provide efficient use of resources for multiple application programs.

Abstract: A method and an apparatus for emulating a console at a graphics workstation terminal uses a second central processing unit to perform the console emulation. A windowing system operating on a first central processing unit interfaces with the operation of the console from the second central processing unit to provide non-destructive console emulation at the workstation terminal. The windowing system maintains a separate console window that the second central processing unit can access transparently to the other windows. The first or host cpu can still perform graphics functions while the second cpu operates the console.

Abstract: In a system including a processor and at least one connector for providing inputs to the processor, which one of a plurality of different types of peripherals is plugged into the connector is determined by sensing any change in the connection of a peripheral to said connector, upon initial start-up of the system and each time a change from not plugged in to plugged in is detected interrogating the peripheral to obtain its type and storing the type of peripheral which is plugged in.

Abstract: A method of communicating between two control units includes transmitting a message from one control unit to the other, checking the message at the other control unit for proper reception, if the reception is not proper, sending a NAK signal from the other to the one control unit, if the reception is proper, sending an ACK signal from the other to the one control unit, and upon receiving an NAK at said one control unit, resending the original message.