MS-DOS clients usually use an MS Network client redirector to send print jobs to Windows NT print servers. They typically use the NetBEUI or TCP/IP protocol, but they might also print with third-party software (such as an LPR utility). Some MS-DOS-based applications create print jobs that contain only ASCII text. Unlike Windows clients that share the same driver for a particular print device, those MS-DOS-based client applications contain an internal version of the driver for each specific print device. This internal driver might not be the correct version of the driver. Often you can modify the driver and printer settings within the MS-DOS-based application or by using an accompanying utility. Check the documentation for the application or utility.
MS-DOS-based applications might not be network-aware, meaning that the application does not allow for a network redirector to forward the print job over the network to a print server. Some network-unaware applications try to print by directly dictating to the parallel port hardware, or they might rely on MS-DOS to control printing and be unable to print correctly to a network print server. Other network-unaware applications assume that they have exclusive control of the printer and therefore don't properly terminate their print jobs. As a result, nothing else prints until the application terminates. You might need to consider upgrading to a network-aware application in order to print over the network.