1. What version of Citect are you using? V3.10 has problems printing through the protection key, use V3.01 or V3.20 instead.
2. Is the printer connected directly to the Citect machine or is it connected via a LAN? If you are printing over the network then you cannot use LPT1.DOS as a port to bypass the print manager.
3. Are you printing through the protection key? If you are printing through the key then you should also refer to article "My Printout is getting garbled" Q1794.
4. Is Citect using the computer comport for anything, ie. Is this an IOServer using the comport? In Citect V3.20 there is a parameter which you can set [DEVICE]ProtectPrinter=1 , this will put higher priority on the printer port but if you are using the comport in Citect then it may lose some characters. This will be minimal if your comport has a 16550 UART.
5. Do you have more than one printer driver installed on the same printer port? eg. If you have a HP LaserJet III printer, then in Control Panel Printers you have the following two lines, a) HP DeskJet 1200C on LPT1: b) HP LaserJet III on LPT1: , Then if you call WinPrint("LPT1:", 0, 0, ""); then the first driver on the list will get used, ie. the DeskJet driver. The printout will be garbled because the printer is a LaserJet. Make sure there is only one driver on any port.

Check your printer setup in Windows to answer the following.

1. What is the version of your printer driver in Windows? Setup - About to see this (usually) check with the printer vendor to see if there is a newer driver.
2. Is "Fast Printing Direct to Port" checked? Click on connect to see this. "Fast Printing Direct to Port" is bad, you should ensure this is unchecked.
3. The HP DeskJet 1200C and PaintJet XL300 have an option called "Page Protection" This can be found under Control Panel, Printers, Setup, Fonts (in driver V3.40) and you should try turning this on, however it may slow down the printing.
4. Is "Use Print Manager" checked? This setting will depend on your use of the printer. Printmanager is very CPU intensive and does not multitask very well, you may find that while you are printing the PC is very sluggish this may be improved by not using Printmanager, however if you have two applications printing simultaneously then both prints may get garbled.