Parallel computing those that use concurrency, are more difficult to write than sequential ones, because concurrency introduces several new classes of potential software bugs, of which race conditions are the most common. Communication and synchronization between the different subtasks are typically some of the greatest obstacles to getting good parallel program performance. A theoretical upper bound on the speed-up of a single program as a result of parallelization is given by Amdahl's law. Traditionally, computer software has been written for serial computation. To solve a problem, an algorithm is constructed and implemented as a serial stream of instructions. These instructions are executed
Sun-1 It was also the console port if no graphical display was installed in the system. Serial port B was wired as a Data Terminal Equipment (DTE) port and had no modem control. Both serial ports could also be used as terminal ports and quite often were allowing 3 people to use one workstation, although two did not have graphical displays. The 16-bit parallel port was a special purpose port for connecting 8-bit parallel port keyboard and 8-bit parallel port optical mouse for workstations with graphical displays. The parallel port was never used as a general purpose parallel printer port. The