printer interfacing

 printer interfacing

hi to all i am trying to interface Parallel Printer. i used only STROBE and BUSY command line and all data line for interface to EPSON LX-300 and EPSON LX-300+II.
the when i connect EPSON LX-300 it works fine and print each and every thing which i feed to it through microcontroller(P89V51RD2BN) but not working properly for EPSON LX-300+II.
i.e. with EPSON LX-300 Printer output is KEIL FOR 8051 with EPSON LX-300+II Printer output is K IL OR 8 51 or it omit some different alphabit

can tell me why this happenning.

 timing

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 RE: timing

you mean to say the timmimg cycle are different for LX300 and LX300+II;

if it is so timmimg cycle are different for LX300,LX300+ and LX300+II

if it is so can you give me some of the particularLX300,LX300+ and LX300+II timming cycle link.

 RE: timing

Just try to slow down your code and see if it starts to work. If so, then slow it down yet a bit more to have a bit of safety margin.

 Just try to slow down your code

or look at the interface control signals to make sure that they are behaving as you expected...

 RE: timing

you mean to say the timmimg cycle are different for LX300 and LX300+II;

if it is so timmimg cycle are different for LX300,LX300+ and LX300+II

if it is so can you give me some of the particularLX300,LX300+ and LX300+II timming cycle link.
No, I mean this is the most likly reason for missed characters.
I have no idea what the timings for these printers are; however, it is likely that later models are different in the requirements.

another possibility is that your timing is "on the edge" and some printers will handle it and some not.

Erik

 RE: timing

the printer port of computer can be used for data in or out, look on this topic for further information, how we can use parallel port for interface with PC.
http://microcontroller51.blogspot.com/2009/04/parallel-port-of-pc.html