1.0

CHAPTER 13 Connecting Devices to Virtual Machines
213
Changing the Input Speed of the Serial Connection
To use the second option, power off the virtual machine and close the VMware ACE
Manager window, then use a text editor to add the following line to your virtual
machine’s configuration file:
serial<n>.pipe.charTimePercent = <x>
This option is useful if you want to squeeze every possible bit of speed from your serial
connection over a pipe to the virtual machine. In principle, there is no limit on the
output speed — the speed at which the virtual machine sends data through the
virtual serial port. In practice, the output speed depends on how fast the application
at the other end of the pipe reads data coming into it.
<n> is the number of the serial port, starting from 0. So the first serial port is
serial0.
<x> is any positive integer. It specifies the time taken to transmit a character,
expressed as a percentage of the default speed set for the serial port in the guest
operating system. For example, a setting of 200 forces the port to take twice as long
per character, or send data at half the default speed. A setting of 50 forces the port to
take only half as long per character, or send data at twice the default speed.
You should first use the guest operating system to configure the serial port for the
highest setting supported by the application you are running in the virtual machine.
Once the serial port speed is set appropriately in the guest operating system,
experiment with this setting. Start with a value of 100 and gradually decrease it until
you find the highest speed at which your connection works reliably.