µVISION: Using Dongles With LPT2 or LPT3

Information in this article applies to:

• C166 Version 4 and Later
• C251 Version 3 and Later
• C51 Version 6 and Later

QUESTION

We have a device programmer that uses the parallel port. This programmer will not work if the dongle is connected in line with it. 

Can we connect the dongle to LPT2?

ANSWER

Yes. You must make a change in the \KEIL\TOOLS.INI file to specify the LPT port for the dongle.

The KEYONLPT identifier specifies the LPT port that is used for the Security Key. For example:

[C51]
PATH=C:\Keil\C51
KEYONLPT=LPT2    // check for security key on LPT2

SEE ALSO

• GENERAL: Upgraded to Windows NT/2000 and Protection Fails
• GENERAL: LPT Dongle on USB Port Replicator

Last Reviewed: Thursday, January 14, 2021