Abstract: A time accounting system for accounting for the time a process spends in a ready state, a wait state, or a running state. The system includes a time-of-day clock coupled to a central processing unit for outputting the time-of-day whenever a process changes state. A memory also coupled to the central processing unit stores the contents of a plurality of addressable process control blocks and each process control block includes first, second, and third storage locations for storing indications of the amount of time an associated process has been in the running, ready, and wait states, respectively. The central processor unit accesses the process control blocks and updates the process times stored therein in accordance with control signals generated by decoding a string of microinstructions stored in a control store memory. The time-of-day clock is accessed each time a process enters one of the running, ready, or wait states and each time the execution of a process is completed.

Abstract: A procedure call mechanism implemented by hardware instructions and a hardware recognizable mechanism known as a stack. A procedure call is utilized by users who have written their programs in a modular way to pass from one program module to another, it is used by user programs to avail themselves of operating system services, and it is used by the operating system itself to achieve a responsive modular structure. The stack is a mechanism permitting the above to be done. A stack is a segment of memory and comprises a number of contiguous portions, known as stack-frames, which are accessed in last in, first out LIFO fashion. Each procedure call creates a stack frame, with subsequent procedure calls creating new stack frames; each exit deletes stack frames thus "popping up" a previous stack-frame. Thus a history of calls is correctly maintained in order to allow a return.

Abstract: A system and method for computer process dispatching in a multiprogramming/multiprocessing environment is disclosed. Each process in the multiprogramming/multiprocessing computer system may be in one of four states at any given time as follows:1. Running -- the process is in control of the computer system and is directing the operation of the central processing unit (CPU);2. ready -- the process is ready to run as soon as it is given control of the CPU;3. waiting -- the process is waiting for an external event to occur so it can either resume running or enter the ready state;4. Suspended -- the process has been temporarily stopped (from a source external to the process).The dispatcher is a firmware/hardware structure that controls the first three states of the process--i.e. running, ready and waiting states.