OSHTSING - EXCEPTION IN DEVICE DRIVER SINGLEQ$ AT EIP=00000971 UNDER 
OS/2 WARP, ALL VERSIONS
10/18/96
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Exception in Device Driver SINGLEQ$ at EIP=00000971 Under OS/2 Warp, 
All Versions
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Please Read Entire Document for Full Explanation of Procedures
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DESCRIPTION

The following error occurs during startup:

Exception in device driver: SINGLEQ$                                          
 TRAP 000d   ERRCD=0000 ERACC=**** ERLIN=********                              
 EAX=7ad00000 EBX=abcd00b2  ECX=0000020 EDX=0000005b                          
 ESI=abdb0000 EDI=1b1b0010 EBP=00035754 FLG=00012292                          
 CS:EIP=07d0:00000971 CSACC=009b CSLIM=00000b50                                
 SS:ESP=0030:000056e8 SSALL=1097 SSLIM=00049eb                                
 DS=0760  DSACC=0093 DSLIM=000000c0 CR0=8001001b                              
 ES=0000 ESACC=**** ESLIM=******** CR2=1bb5101a                               
 FS=0000 FSACC=**** FSLIM=********                                             
 GS=0000 GSACC=**** GSLIM=********               
                              
 The system detected an internal processing error                              
 at location ##0160:fff5c34c-000d:a34c.                                        
 60000  9084                                                     
              

Explanation:  

During startup, when the base video handler initializes, the 
SVGADATA.PMI file is                 
opened and parsed. If there is no SVGADATA.PMI file or it contains 
unexpected or invalid information 
for the chipset, the video PMI (protected mode interface) dynamic link 
library is unlinked. Then, when the PM (presentation manager) driver 
attempts to set the video mode (to bring up the Desktop), it finds the 
video PMI unlinked and attempts to make the call to reload it. This is 
an unauthorized call and causes a trap in the kernel.

The end result is an exception in the PMDD.SYS device driver with: 
SINGLEQ$ at CS:EIP=0950:00000971.

The same process can occur for other device drivers.  

What is PMDD.SYS?

PMDD.SYS is the interface layer between the presentation manager and 
the device drivers. This device driver is not specific to video drivers. 
It is also used as the interface for other device drivers; 
such as sound cards, PCMCIA, or SCSI devices. Video seems to be the 
most common cause, although there have been several cases of other 
device drivers causing the same problem. In prior 
versions of OS/2, the same problem occurred, but only displayed a blank 
screen.  In OS/2 Warp versions, instead of a blank screen, you see a trap screen.

RESOLUTION

How do I tell what is causing it?  

To determine the cause of an exception in SINGLEQ$, look at which part 
of the startup sequence that the trap 000d in SINGLEQ$ occurs.
  
Restart the system; press Alt-F2 when you see the OS/2 in the upper 
left corner of the screen to display the device drivers as they load. 

If the trap occurs while these device drivers are loading, then the 
problem is with one of these drivers, not the video. In this case, 
check the CONFIG.SYS file for invalid or duplicate device driver 
statements.  Also, verify that you are using the correct drivers for 
your hardware.

If you see the logo screen and then a black screen with a blinking 
cursor before the trap in SINGLEQ$, then it is likely that the 
incorrect video driver is loaded. Restart the system; press Alt-F1 
when the OS/2 appears in the upper left corner of the screen. 
At the Recovery Choices screen, choose V in OS/2 Warp 3 or F3 in OS/2 
Warp 4, to reset the system to VGA drivers. Then, re-evaluate which 
chipset you have, locate the appropriate drivers, and install them. 

Isn't this a defect?

This is not a defect because this trap ONLY occurs when an invalid 
configuration is present. If the system is configured properly, 
the trap does not occur. Basically, the trap occurs to inform a 
technician that an invalid configuration is present. This is 
working as designed.



warp4
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