The modified von Neumann architecture (also known as the 'registers on bus' architecture) is a parallel processor architecture that is slightly different from the normal von Neumann architecture to allow for easier parallel processing.

The object of the architecture is to allow a thousand processors (with memory) on each chip, simplicity, special purpose processors and circuitry, easy interprocessor communication, and easy normal programming. This is accomplished by using virtual processors that move among the physical processors, using the physical processors as needed. Programs are written for the virtual processors rather than physical processors.

Some parallel processing designs with the normal von Neumann architecture have multiple processors using shared memory. The modified von Neumann architecture has multiple virtual processors using shared memory and shared physical processors. Each von Neumann processor can be broken up into a number of smaller, simpler processors (for example, a multiplier) that can be used simultaneously. Nevertheless, a modified von Neumann architecture processor is programmed almost exactly the same way as a normal von Neumann architecture processor. The physical processors, often including small blocks of memory, are small, allowing thousands of processors on a chip with roughly half of the chip being used for memory. A program is written for a virtual processor using many small simple physical processors almost exactly as if there were large physical processors as in the normal von Neumann architecture. There can be thousands of virtual processors on a chip being processed and processing data simultaneously.

This architecture solves the two main problems with many-processor Von Neumann processors, programming and communication.