Farallon Communications 612, 412 manual Optimizing serial port performance, PC serial ports

Advanced Features 6-9

Optimizing serial port performance

The serial port speed of most PC and Macintosh computers limits the computer’s maximum data transmission rate. Typically, PCs and Macintosh computers are limited to a maximum transmission speed of 115.2 Kbps. However, advanced serial cards and drivers are available to boost the serial port speed up to 230.4 Kbps.

PC serial ports

For sustained performance at data rates higher than 57.6 Kbps, Farallon recommends that your PC’s serial COM port be equipped with a 16550 universal asynchronous receiver/transmitter (UART).

To determine what type of UART is installed in your PC, type msd at the DOS prompt to run the Microsoft Diagnostic Program.

You can use software utility tools to optimize the performance and reliability of the serial port through the 16550 UART. Recommended tools include WFXCOM.DRV, available on a number of BBS and ftp sites, or TurboCom, available from Pacific CommWare, Inc., of Ashland, Oregon (541-482-2744).

Macintosh serial ports

Macintosh models equipped with 680x0 processors are generally limited to serial port speeds of 57.6 Kbps. Power Macintosh and AV models equipped with Apple’s GeoPort technology can generally support serial speeds of 115.2 Kbps or higher. For optimal performance, Farallon recommends installing Apple’s Serial DMA extension, version 2.02 or later, which requires Macintosh System

7.5or later. If you are using System 7.5.3 or later, the correct version of the serial driver is already installed in your system and you do not need to add this extension. For more information about serial connections, see the “Configuration using a Macintosh computer” section on page 5-2.