Error Messages and Codes 
                                Critical Errors 

       Critical errors can be identifies as codes 150 to 199 and usually
       terminate program execution.


               NUMBER         CAUSE 
 ----------------------------------------------------------------------------

                   150     Disk is Write-Protected
                   151     Unknown Unit
                   152     Drive Not Ready
                   153     Unknown Command
                   154     CRC error in Data
                   155     Bad Drive Request Structure Length
                   156     Disk Seek Error
                   157     Unknown Media Type
                   158     Sector Not Found
                   159     Printer Out of Paper
                   160     Device Write Fault
                   161     Device Read Fault
                   162     Hardware Failure

       Consult your DOS Programmers Reference manual for more details
       about critical errors.