Re: printing problem

From: Jim P (Jim_P_at_mad.scientist.com)
Date: 11/29/04 

Date: Mon, 29 Nov 2004 12:38:19 -0800

Bruce Roberts wrote:

> "Peter J. Dobrovka" <dobrovka@3dtt.de> wrote in message
> news:68fkq05kia1hlch1peunr0djft9di6bq1q@4ax.com...
>
>
>>The phenomenon is this: On 50% of all computers the printing does not
>>start
>>until the program is terminated. You can see the print job in the
>>spooler, but
>>the moment when it disappears and the printer is beginning to work
>>never comes.
>
>
> Printer drivers can be configured to start printing 'immediately' or only
> after a job is 'finished'. In Delphi if one is using the Printer variable
> EndDoc is required to inform Win that a print job is done. If one is using
> file i/o, one has to close the file before any changes to it will be
> committed, i.e. printed.
>
>
Ah most printers today are not printers in that term, They are page
printers. All laser printers wait until they have a full page to print
before they print. As the printing process is that of a full page.

The same can be said for Ink Jet printers. More because of the way the
page may be presented to the printer. With the page make up language
that is used to send data to the printer. The information may not be in
simple start to finish order. So the printer and printer driver waits
till it receives a full page before printing.

In this a page completion code is required. Or some type of flush command.

I have seen the command but have not really looked at it in detail. Have
not got to the reports part of my project yet. but know that I am going
to have to use it.

And why only on some printers. The page margins vary from printer to
printer. The top of form and bottom of form can be different and this
means on one printer it will see a full page and on the next it will
have an other line to go. And thus the page does not print - - till
more information triggers the full page.

Got burned by this years ago. I was traating a laser printer as a line
printer and would only get a large pause until I triggered finish of the
printing - - it might have been a front panel button on the old Toshiba
Laser printer - - so I added software for this. That was years ago. As
long as a full page was sent - no problem. Part page. oops. Printer sits
and waits for a full page or is told the page is complete.

Jim P.

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