Microsoft KB Archive/63598

MODE Does Not Set 2 Stop Bits Correctly PSS ID Number: Q63598 Article last modified on 07-14-1993 PSS database name: O_MSDOS

4.00 4.01 4.01a

MS-DOS

Summary:

The MS-DOS versions 4.0, 4.01, and 4.01a MODE command does not set the stop bits correctly when you specify 2 as the number of stop bits.

The “Microsoft MS-DOS User’s Reference” documents 2 as being a valid value for the stopbits parameter. However, when the number of stop bits given is 2, the MODE command sets the port to 1 stop bit. MODE does report that the port has been set to 2 stop bits.

The following MODE command

MODE COM1:9600,n,8,2

reports the following:

COM1: 9600,n,8,2,-

However, the COM1 port is actually set to 9600,n,8,1.

Microsoft has confirmed this to be a problem in MS-DOS versions 4.0, 4.01, and 4.01a. This problem does not occur in later versions of MS-DOS.

Additional reference words: 4.00 4.01 4.01a noupd

Copyright Microsoft Corporation 1993.