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From: unbent@ecsvax.UUCP (Jay F. Rosenberg)
Newsgroups: comp.sys.ibm.pc
Subject: Need help with Hayes 1200B software reset.
Message-ID: <2541@ecsvax.UUCP>
Date: Sat, 10-Jan-87 16:52:16 EST
Article-I.D.: ecsvax.2541
Posted: Sat Jan 10 16:52:16 1987
Date-Received: Sat, 10-Jan-87 23:40:56 EST
Distribution: na
Organization: UNC Chapel Hill
Lines: 25
Keywords: hayes 1200b modem uart reset


	According to the documentation, it's supposed to be possible to get
the reset effect of a cold reboot (turning the machine off and on) for the
Hayes 1200B board modem by doing appropriate writes to Bit 2 of the UART's
Modem Control Register.  I've tried to implement this using Debug and
various Turbo Pascal routines, but failed miserably every time.
	Could anyone point me in the direction of a piece of software which
actually implements this documented function, or tell me how to write my
own?  Here's what the Haye's 1200B manual says:
	"To perform a processor reset, equivalent to power off/power on,
write to bit 2 of the UART's Modem Control Register (see Chapter 4).  Write
a 1, wait at least 50 ms, then write a 0 to OUT 1."
	And in Chapter 4:
	"Modem Control Register (MCR) 3FC r/w  ...
Bit 2:   Output 1 (OUT 1):   1 Resets the modem; equivalent to power
off/power on....  Must be held at 1 for at least 50 ms.
			     0 Setting for normal operation.  After
executing a reset, write a 0 to this bit to clear it."
	Any and all help would be deeply appreciated!

-- 

JAY ROSENBERG     Dept. of Philosophy     UNC     Chapel Hill, NC   27514
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