Softpaq Solution:   SP1068
File Name:    MASKIRQ.EXE
Title:   Fixes DOS Communications Programs on Laptops
Version: N/A

CATEGORY:  Drivers / Miscellaneous

EFFECTIVE DATE:  03-6-95

PRODUCTS AFFECTED:  Elite, Aero and Contura 400 laptops

OPERATING SYSTEM:  MS-DOS 5.0 or greater

SYSTEM CONFIGURATION:

DESCRIPTION:  Some DOS communication programs unable to load or unable to talk to the serial port/modem on the laptop products affected.   DOS does not provide interrupt driven access to serial ports, so each DOS program that accesses a serial port/modem has its own interrupt handler code.  Some of these programs will refuse to load or talk to the serial port if they think that the port is already in use by another program.   One of the ways that a program can detect that another program is using a serial port is by examining whether or not the Interrupt Request (IRQ) line is enabled (unmasked) for that serial port.    

The serial port interrupts on the ELITE, AERO and Contura 400 laptops are left unmasked after POST to solve problems with some software products.  Unfortunately, other software products seem to be adversely affected by the fix for the first group.    MASKIRQ.EXE allows the user to control the mask/unmask status for IRQ lines 3,4,5 and 7 to suit the programs in use on any given machine.   MASKIRQ may be run from a DOS batch file or as a line in CONFIG.SYS.   

NOTE:  If a DOS program is having trouble in a Windows DOS box, it may be best to change the mask/unmask status BEFORE STARTING Windows. 

HOW TO USE:

1.  Download the SoftPaq to a directory on your hard drive and change to that directory.  The file that is downloaded is SP1068.EXE.

2.  From that drive and directory, execute the SoftPaq file:
SP1068 [ENTER]
The following two files should be created:
MASKIRQ.EXE
MASKIRQ.DOC

3.  You may delete the downloaded file SP1068.EXE if you wish.

4.  See MASKIRQ.DOC for specific installation instructions and additional help.

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