textfiles/programming/srbediff.txt

                      What's The Difference
                       Between The BE3011
                          and SmartROM?


BE3011 - BIOS TABLE EXPANDER TABLE

The BE3011 (also known as BE, BTE, and BETTY) is basically just
what it is called; a BIOS Table Expander.  The BE3011 is a ROM that
has a table of drive geometry entries ranging in capacity of 80MB
to 1G and is used to compliment the drive geometry entries that
already exist in the BIOS Table on the motherboard.

Most motherboard BIOS's, however, only have drive geometry support
in the standard range for up to a 140MB disk drive.  This standard
range is commonly known as "Drive Types 1-46".  Some BIOS's do
offer an expanded table beyond Type 46 and, in some cases, a User
Definable Disk Drive Type (or UDP, for User Definable Parameters). 
However, because the DPT controller emulates the WD1003 disk
controller, it cannot utilize "standard" Drive Types that exceed
number 46 because this secondary drive table is stored in different
areas of system ROM on every
machine depending on the BIOS manufacturer.  The Drive Type range
of 1-46 is standardized on every machine, however, and can be found
at system ROM address F000:E679.  The UDP type can be used with the
DPT controller even though it does not appear in the standard Type
1-46 range.  Refer to UDP.TXT or read Bulletin 7 on the Technical
Support BBS for details on installing with UDP's.

As the inability to have support for large capacity disk drives in
the standard Type 1-46 range became more apparent, DPT developed
the BE3011 BIOS Table Expander.  The BE3011 sets the motherboard
CMOS to Type 1 (typically a 10MB drive entry) and sets up a
software vector (INT41) so that whenever the operating system makes
a disk call to Type 1, it will skip over the 10MB entry listed and
follow the vector to the BE3011 address (typically C800) where the
DPT drive table is stored.  The installation of the BE3011 table
into system memory is accomplished by running DPTFMT on the disk
drive to be used.


WHEN TO USE THE BE3011

The BE3011 is only needed when using an operating system that is
BIOS dependant, and you are using a DPT controller in emulation
mode, and the hard disk you want to install is not supported by
your motherboard BIOS.  Although the BE3011 is compatible with all
DPT controllers, it is usually only used on the PM3011 and PM2001
controllers.  The BE3011 comes standard on the PM3011 controller
and is available as on option on the PM2001.  PM2011 and PM2012
controllers usually take advantage of DPT SmartDrivers or SmartROM
thus eliminating the need for the BE3011.  The following chart
shows which operating systems need the BE3011 and which do not:

Operating System             Needs BIOS Expansion
-------------------------------------------------
Interactive                        YES
MS/PC DOS                          YES
Novell 2.1x, 2.2x, 3.x             YES
OS/2                               YES
PCMOS                              YES
Concurrent DOS                     YES
PICK                               YES
Microport UNIX                      NO
SCO UNIX                            NO
Xenix                               NO
QNX                                 NO
THEOS                               NO
Novell 2.0x                          *

* Novell 2.0x will not operate with the BE3011.  The DUB14 from
Golden Bow Systems is recommended and like the BE3011, will socket
directly onto the PM3011 or PM2001 controller.


BR401x - SmartROM

The SmartROM (also known as SR and DPT BIOS) is slightly more than
just a table entry as it has intelligence.  Instead of having a
table of drive geometries, SmartROM instead formulates it's own
drive geometry based on the capacity of the drive installed. 
SmartROM uses a 64 head 32 sector 1 cylinder = 1MB algorithm
(example:  350MB drive would have a SmartROM geometry of 350
cylinders, 64 heads, and 32 sectors).  SmartROM is used primarily
for DOS, and because SmartROM sets the system CMOS to NO DRIVES
INSTALLED, SmartROM is not limited to the 528MB DOS limitation
we've all come to know and hate.


WHEN TO USE SMARTROM

SmartROM is used primarily for DOS, and is poses no benefits for
any other operating system besides DOS.

SmartROM is compatible with MS/PC DOS versions 3.3 through 5.0 on
the PM2012, PM2011, PM2001, and PM3011E/75 controllers.  Benefits
include:

PM2012 - SmartROM provides DOS EISA enhanced mode, Bus Mastering,
support for hard disks over 528MB, support for tape drives, support
for CDROM drives, and support for multiple 2012 controllers. 
Download SUPDEV.TXT for details on supported devices.

PM2011 - SmartROM provides DOS support for hard disks over 528MB,
support for tape drives, support for CDROM drives, and support for
multiple 2011 controllers.  Download SUPDEV.TXT for details on
supported devices.

PM2001 -  SmartROM provides DOS support for hard disks over 528MB,
support for tape drives, support for CDROM drives, and support for
multiple 2001 controllers.  Download SUPDEV.TXT for details on
supported devices.

PM3011E/75 - SmartROM provides DOS support for hard disks over
528MB.

For operating systems other than DOS, the above benefits may be
achieved with the installation of a DPT SmartDriver.  Download
UDP.TXT from the Technical Support BBS for details on SmartDriver
benefits.