Sign in to see your user information My eBay Expand My eBay Summary Recently Viewed BidsOffers Watch List Purchase History Selling Saved Searches Saved Sellers Messages Collect Spend Learn more Notification Expand Basket Loading.

User Agreement, Privacy, Cookies and AdChoice Norton Secured - powered by Verisign.

Connecting this to pin 7 (signal reference ground) is a common practice but not essential.

For Serial Mouse 2.1 A Serial Port On

A male Mini DIN-8 connector used for a serial port on a Macintosh or SGI style computer.

Serial ports are still used in these areas as they are simple, cheap and their console functions are highly standardized and widespread.

For Serial Mouse 2.1 A Software From The

A serial port requires very little supporting software from the host system.

Very low-cost systems, such as some early home computers, would instead use the CPU to send the data through an output pin, using the so-called bit-banging technique.

Before large-scale integration (LSI) UART integrated circuits were common, a minicomputer or microcomputer would have a serial port made of multiple small-scale integrated circuits to implement shift registers, logic gates, counters, and all the other logic for a serial port.

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.

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.

Small-form-factor systems and laptops may omit RS-232 connector ports to conserve space, but the electronics are still there.

RS-232 has been standard for so long that the circuits needed to control a serial port became very cheap and often exist on a single chip, sometimes also with circuitry for a parallel port.

The desire to supply serial interface cards with two ports required that IBM reduce the size of the connector to fit onto a single card back panel.

Starting around the time of the introduction of the IBM PC-AT, serial ports were commonly built with a 9-pin connector to save cost and space.

However, presence of a 9-pin D-subminiature connector is neither necessary nor sufficient to indicate use of a serial port, since this connector was also used for video, joysticks, and other purposes.

The Macintosh included a standard set of two ports for connection to a printer and a modem, but some PowerBook laptops had only one combined port to save space.

Since most devices use only a few signals, smaller connectors can often be used.

Standard EIATIA 561 specifies a pin assignment, but the Yost Serial Device Wiring Standard 2 invented by Dave Yost (and popularized by the Unix System Administration Handbook) is common on Unix computers and newer devices from Cisco Systems.

Many devices dont use either of these standards.

P10C connectors can be found on some devices as well.

Digital Equipment Corporation defined their own DECconnect connection system which was based on the Modified Modular Jack (MMJ) connector.

This is a 6 pin modular jack where the key is offset from the center position.

As with the Yost standard, DECconnect uses a symmetrical pin layout which enables the direct connection between two DTEs.

The ground signal is a common return for the other connections; it appears on two pins in the Yost standard but is the same signal.

The DB-25 connector includes a second protective ground on pin 1.

Drivers For Serial Mouse 2.1 A