Serial port ports with pinouts and voltage levels incompatible with RS-232. Inter-operation with RS-232 devices may be impossible as the serial port cannot withstand the voltage levels produced and may have other differences that "lock in" the user to products of a particular manufacturer. Low-cost processors now allow higher-speed, but more complex, serial communication standards such as USB and FireWire to replace RS-232. These make it possible to connect devices that would not have operated feasibly over slower serial connections, such as mass storage, sound, and video devices. Many personal computer motherboards still have at least one serial port, even if accessible
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