Microsoft KB Archive/20964

Serial Interface and Parallel Printers

PSS ID Number: Q20964 Article last modified on 11-02-1994

3.x 4.00 5.00 5.50 6.00

MS-DOS

= SUMMARY =

The following are two ways in which Word talks to a serial printer:

  If you specify “COM1:” in the Print Options “setup:” field, the program uses the serial interrupt in the BIOS. The protocol used is determined by the SerialInterface flag in the PRD header. The value of the SerialInterface flag is ignored if the printer port used is LPT1:, LPT2:, or LPT3:. If COM1: or COM2: is used, the value tells Word what protocol to use; 40960 is XON/XOFF and 49152 is ETX/ACK. The only difference between the two is the control characters used for start and stop signals.   If a DOS MODE command is used to redirect LPT1: to COM1: and LPT1: is specified as the printer, no software handshaking is done but the BIOS handles hardware handshaking. 

KBCategory: kbprint KBSubcategory: Additional reference words: ============================================================================= Copyright Microsoft Corporation 1994.