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
7.5 or 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.