From: MLONG@isucard.card.iastate.edu
Subject: Re: Problems with IBM Laptop and serial ports
Organization: CARD
Date: Tue, 8 Sep 1992 19:46:35 GMT

In article <1992Sep8.003617.2374@menudo.uh.edu>                                 
cosc16to@menudo.uh.edu (Andy Hakim) writes:                                     
                                                                                
>jeff@ryhope.del.dec.com (Jeff Finkelstein) writes:                             
>:                                                                              
>: I have some programs that I have written that contain their own serial       
>: port interrupt routines. The code works fine on every system I have          
>: tried it on except for the IBM PS/2 Model L40X (I got the model number       
>                                                                               
>Well, a friend just purchased the L40sx laptop and there there some            
>major problems using certain mice with it.  He bought a generic clone          
>serial mouse (a NewIdea Beetle Mouse) and while the mouse driver               
>loads ok (it detects a ms compatible mouse) there is no movement.              
>Then he tried a Genius serial mouse, on which there was no                     
>vertical movement.  The ONLY mouse which has worked is a Microsoft             
>"PS/2 Compatible Serial Mouse".                                                
>                                                                               
>The strange part is that all these mice work fine on other computers,          
>including other laptops we've tried.   What's so special about                 
>the L40's serial port?  (obviously there is nothing wrong with the             
>port since the MS mouse works fine)...                                         
>                                                                               
>-andy                                                                          
>cosc16to@menudo.uh.edu                                                         
>                                                                               
                                                                                
L40's are very sensitive to which brand of mouse you use.  From the PS2ASST     
program:                                                                        
 Non-Micro Channel System Qs & As                                               
 Q.  When I connect a Microsoft Mouse to the PS/2 Model L40 mouse port, and sus 
pend                                                                            
 the system (by closing the lid), the mouse won't work when I reopen it.  If I  
connect the                                                                     
 mouse serially and suspend, the mouse works fine.  Also, if I use an IBM mouse 
on                                                                              
 the mouse port, it works too.                                                  
                                                                                
 A.  This is a known problem with the L40, having to do with the specific volta 
ge                                                                              
 requirements of the Microsoft Mouse.  At present there is no permanent fix.  A 
s a                                                                             
 workaround plug the numeric keypad into the mouse port, and plug the Microsoft 
mouse                                                                           
 into the keypad.  This will work.  This problem only occurs during suspend/res 
ume: not                                                                        
 at any other time.                                                             
                                                                                
Mike Long                                                                       
Iowa State University                                                           
Xref: sparky comp.sys.ibm.ps2.hardware:1622 comp.sys.ibm.pc.hardware:24071 biz.sco.general:3290