ODD PROBLEMS WITH CP BACKUP ON 386 AND 486 COMPUTERS
Programs:  CPBACKUP, WNBACKUP       Versions: 7
 
SITUATION:
Central Point Backup for Windows or DOS fails on a 486 or 386 computer.
Error messages include:  "No tape drive detected;" "Invalid DMA Channel;"
"Format Failure;" "Track 0 Bad."
 
Other problems include:  An excessive number of pauses when backing up to
tape; the Confidence Test will fail at high and medium speeds; CP Backup
will frequently lock.
 
WORKAROUND/SOLUTION:
Use one or more of the following steps:
 
1.  Eliminate any software conflicts.  Create and cold boot (power off) with
a boot disk that contains the following:
 
CONFIG.SYS      FILES=40
                BUFFERS=40
                STACKS=34,128
                DEVICE=<driver>         (any required device for the system)
                DEVICE=HIMEM.SYS        (if testing in Windows)
 
Note:  Be sure to copy the <driver> and HIMEM.SYS to the boot disk if they
will be used.
 
AUTOEXEC.BAT    PROMPT=$P$G
                PATH=<CPBACKUP directory>;<WINDOWS directory>;
                SET CPBACKUP=<CPBACKUP directory>
 
Note:  If Windows 3.0 is being tested with MS DOS 5.0, be sure to copy the
file WINA20.386 from the root directory of the hard drive to the floppy.
Windows 3.0 requires that this file be in the root directory of the boot
drive in order to run when DOS 5.0 is being used.
 
2.  Eliminate hardware conflicts with other items that may be trying to
access the data bus at the same time: i.e., the video card; hardware 
cache; turbo function; SCSI controller; other.  Try one or a combination of 
the following options:
 
Option a.  Use CPBACKUP /NO at the DOS prompt; for CP Backup for Windows,
select the CP Backup icon in Program Manager, then go to File/Properties and 
add /NO to the end of the Command Line; or set the Backup speed to Medium 
in CP Backup's Configure menu.
 
Option b.  If the video adapter is a 16-bit adapter, check that it is
properly configured for 16-bit operation.  (See the adapter's documentation.) 
 An 8-bit video card may need to be upgraded to a 16-bit card.
 
Option c.  Use one of the following to shadow video adapter ROM.  This
procedure will copy it to RAM for faster access and reduced bus access time:
 
- Machine's hardware setup utility or CMOS setting;
 
- Memory manager (eg. 386MAX, which does this automatically, QEMM using the 
ROM=c800 parameter, etc.)

- A utility provided with the video adapter (eg. RAMBIOS.SYS, 
FASTBIOS.SYS, TVGABIO.SYS, RAPIDBIO.SYS, etc.).
 
Option d.  Use an alternate memory manager such as HIMEM.SYS if using
QEMM386.SYS, or none at all.
 
Option e.  Disable the machine's hardware cache (check the documentation for
the computer).  Note:  A hardware cache is different than a software cache
program such as PC-Cache or SMARTDrive.
 
Option f.  Turn machine's turbo mode OFF, or use a different CPU speed.
Check the computer's documentation for the method used.  Common methods are:
a button on the front of the computer, ATSLOW program, CTRL-ALT-<MINUSKEY>,
or a CMOS setting.
 
Option g.  Disable any background operations such as modem or FAX boards, or
parallel port link transfers.
 
Option h.  Look for control programs such as ASPI4DOS.SYS (for an Adaptec bus
mastering controller) or the BUSONOFF program (for Western Digital 
1007 FAAST bus mastering controller).  Reduce the "ON" time for the bus with 
the following parameters for ASPI4DOS.SYS:
 
DEVICE=ASPI4DOS.SYS /N07
 
For BUSONOFF, set the ON time to 4000 ns and the OFF time to 1875 ns.
 
3.  If problems continue in CP Backup for Windows, try the following:
 
a.  In the Windows Setup program, change the Display setting and select a
driver specific for the video card.  The driver should be provided either
with Windows or with the video card.  Try a driver with lower resolution:
standard VGA; 640x480x256 color; try other 256 color options.  Avoid 16
color options.
 
b.  Close all other Windows applications and disable enhancements to standard
Windows configuration.  Press CTRL-ESC to check the Task List of what is
active.  Remove anything from the LOAD= and RUN= lines in the WIN.INI, and
hold the SHIFT key when starting Windows 3.1 to avoid loading the Startup
Group.
 
c.  Add "DMABufferSize=64" to the SYSTEM.INI [386Enh] section.
 
d.  Try Windows in Standard mode instead of Enhanced.

CAUSE:
In essence, the architecture of these machines causes the bus to be very
busy.  Since the DMA channels (which CP Backup uses) also use the bus, when
the bus is overtaxed, it can cause DMA errors or failures.  By reducing the
load on the bus, the problems may be corrected.
 
 
 FaxBack document #30013, updated June 1, 1992