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From: bobm@hp-pcd.UUCP (bobm)
Newsgroups: net.micro.pc
Subject: Re: why does program stop print spooler?
Message-ID: <15200029@hpcvlo.UUCP>
Date: Fri, 12-Sep-86 13:21:00 EDT
Article-I.D.: hpcvlo.15200029
Posted: Fri Sep 12 13:21:00 1986
Date-Received: Tue, 16-Sep-86 20:59:36 EDT
References: <729@tekred.UUCP>
Organization: Hewlett-Packard - Corvallis, OR
Lines: 11
Nf-ID: #R:tekred:-72900:hpcvlo:15200029:000:459
Nf-From: hpcvlo!bobm    Sep 12 09:21:00 1986


	The PRINT command works by taking over an interrupt called the 
	'DOS IDLE' hook (Int 28H). This hook is called by DOS whenever 
	it is in an idle state, such as waiting for keyboard input. Every
	time int 28 is called, PRINT dumps a burst of characters to the 
	printer. If you have a program that doesn't do many DOS I/O calls,
	Int 28 will not be called, and the spooler won't have a chance 
	to run until you exit to DOS.

	Bob May
	hplabs!hp-pcd!bobm