1. Introduction.- 2. Classification of Parallel Processors.- 2.1. A Brief History of Classification Schemes.- 2.2. The Classification Scheme Used in This Work.- 2.3. A Look at the Classification Characteristics.- 2.3.1. Applications.- 2.3.2. Control.- 2.3.3. Data Exchange and Synchronization.- 2.3.4. Number and Type of Processors.- 2.3.5. Interconnection Network.- 2.3.6. Memory Organization and Addressing.- 2.3.7. Type of Constructing Institution.- 2.3.8. Period of Construction.- 2.4. Information-Gathering Details.- 2.4.1. Classification Choices.- 2.4.2. Qualifications for Inclusion.- 2.4.3. Extent.- 2.4.4. Sources.- 2.5. An Apology.- 3. Emergent Trends.- 3.1. Applications.- 3.1.1. Correlation with Period of Construction.- 3.1.2. Correlation with Constructing Institution.- 3.1.3. Correlation with the Control Mechanism.- 3.1.4. Correlation with the Data Exchange and Synchronization Mechanism.- 3.1.5. Correlation with the Number and Type of Processors.- 3.1.6. Correlation with the Interconnection Network.- 3.1.7. Correlation with the Memory Organization.- 3.2. Mode of Control.- 3.2.1. Correlation with the Period of Construction.- 3.2.2. Correlation with the Type of Constructing Institution.- 3.2.3. Correlation with the Data Exchange and Synchronization Mechanism.- 3.2.4. Correlation with the Number and Type of Processors.- 3.2.5. Correlation with the Interconnection Network.- 3.2.6. Correlation with the Memory Organization.- 3.3. Data Exchange and Synchronization.- 3.3.1. Correlation with the Period of Construction.- 3.3.2. Correlation with the Type of Constructing Institution.- 3.3.3. Correlation with the Number and Type of PEs.- 3.3.4. Correlation with the Interconnection Network.- 3.3.5. Correlation with the Memory Organization.- 3.4. The Number and Type of PEs.- 3.4.1. Correlation with the Period of Construction.- 3.4.2. Correlation with the Constructing Institution.- 3.4.3. Correlation with the Interconnection Network.- 3.4.4. Correlation with the Memory Organization.- 3.5. Interconnection Network.- 3.5.1. Correlation with the Period of Construction.- 3.5.2. Correlation with the Type of Constructing Institution.- 3.5.3. Correlation with the Memory Organization.- 3.6. Memory Organization.- 3.6.1. Correlation with the Period of Construction.- 3.6.2. Correlation with the Type of Constructing Institution.- 3.7. Type of Constructing Institution.- 3.7.1. Correlation with the Construction Period.- 3.8. Period of Construction.- 3.9. Summary of the Correlations.- 4. Popular Machine Models.- 4.1. Exposing the Complex Patterns.- 4.2. General-Purpose Machines.- 4.2.1. Model I - MIMD, Shared Memory.- 4.2.2. Model I, the High-End, Numeric Variant.- 4.2.3. Model II - MIMD, Message Passing.- 4.2.4. Model II, the High End.- 4.2.5. Model III - General Purpose SIMD Machines.- 4.3. Model IV - Image (and Signal) Processing SIMD Machines.- 4.4. Model V - Database MIMD Machines, Two Variants.- 4.5. Trends in Commercialization.- 4.5.1. The Number Crunchers.- 4.5.2. The Multiprocessor Midrange.- 4.5.3. The Hypercube.- 5. The Shape of Things to Come?.- 5.1. Underlying Assumptions.- 5.2. Applications.- 5.3. Control.- 5.4. Data Exchange and Synchronization.- 5.5. Number and Type of PEs.- 5.6. Interconnection Networks.- 5.7. Memory Organization.- 5.8. Sources.- 5.9. Classification of Parallel Computers.- 5.10. Summary.- Appendix: Information about the Systems.