
          Document:  PCI IDE Controllers for OS/2
        Maintainer:  Patrick Duffy, duffy@theory.chem.ubc.ca
    Revision Dates:  11/3/95
       Archived at:  ftp.netcom.com, in directory /pub/ab/abe/
                     CompuServe (GO BENCHMARK)
         Web pages:  http://warp.eecs.berkeley.edu/os2/workbench/work.htm
                     http://www.os2forum.or.at/english/info/os2hardwareinfo/
                     (note that the first URL may not have up-to-date
                     versions of the lists)

This document is intended for use by individuals and corporations in a
non-commercial manner.  It may be distributed freely within those
limitations.  Commercial use of this document in any manner requires
prior written permission of the author.

There seems to be a proliferation of PCI IDE hardware both built in to
PCI motherboards or available as separate cards.  Some of it is reported
to work well, and some of it is best left unused.  Two of these
controllers, the PC Tech RZ1000 and CMD 640, have been the cause of much
discussion on UseNet, as both have serious flaws which could result in
data corruption.  Both are very commonly employed in motherboards of all
types (the PC Tech RZ1000 was used in the Intel Premiere series of
boards and the CMD 640 is still used in many motherboards, such as the
Asus P54SP4). The full story is below. I've therefore created this PCI
IDE list so that people will know if their particular PCI IDE
implementation will work with OS/2.  I've tried to keep this information
as accurate as possible, but if you spot any flaws or omissions, please
do not hesitate to let me know.  Much of this was received from sources
within IBM.  You may see square brackets beside certain chipsets.  If
the word "confirmed" appears therein, this means that the bug detailed
in the description to follow along with the subsequent fix have been
confirmed to me by IBM.  I've placed a '*' beside the controllers which
seem to work well.  The vendor's name and PCI ID appear in HEX/decimal
in brackets beside the controller name. Dates in brackets indicate the
last revision date for the related entry.

Useful numbers: (9/9/95)
---------------
BusLogic:  (408) 492-9090 (Voice)
           (408) 654-0760 (tech. support -- 7 A.M. - 5 P.M.
                           Pacific Time, Mon. - Fri.)
           (408) 492-9118 (FAX)
           (408) 492-1984 (BBS - N81)
           techsup@buslogic.com (E-Mail tech. support)
           ftp.buslogic.com (FTP site)
           www.buslogic.com (WWW site)

CMD:       (800) 426-3832 (sales)
           (714) 454-0800 (sales)
           (714) 455-1656 (FAX)

DTC:       (408) 942-4010 (BBS)
           (408) 942-4005 (Faxback)
           (408) 942-4081 (sales)
           (408) 942-4027 (FAX)

PC Tech:   (612) 345-4555

Tekram:    www.tekram.com (WWW site)

                                Chipsets
                                --------

1) CMD 640 (CMD Technology Inc.:  1095/4245) (9/4/95)

   There are _four_ problems with this particular chip.  Here's the
   first one:

   [confirmed]

   Channels (two IDE drives may be attached to each IDE channel) cannot
   be operated concurrently because there is a single I/O queue for both
   channels.  Simultaneous reads to both channels will cause data
   corruption.  This is not mentioned in the chipset errata.

   Here's the second one:

   [confirmed]

   Their stand-alone PCI board does not have a BIOS and appears to
   come-up disabled per the PCI definition. Its really difficult to
   tell whether a PCI-IDE controller is operating in 'legacy' mode
   since (at least) the CMD chipset does not update the PCI config
   space with the legacy base port addresses. Also convincing PCI to
   route IRQ 14/15 to a PCI Int is problematic unless the motherboard
   BIOS explicitly supports this function.

   Here's the third one:

   [confirmed]

   The CMD chipset also has a documented restriction that it will not
   support DWORD config write cycles.  Of course the Award BIOS on the
   (Vobis) motherboard on which testing was being performed did not
   issue byte/word config cycles explicitly and instead implemented all
   config read/write services as read/modify/write of DWORD data. The
   net result was that the system PCI BIOS could not be used to program
   the motherboard chipset!

   Here's the fourth one:

   [confirmed]

   Some systems have the floppy drive changeline connected to the same
   line as the 640 chipset.  With this setup, data corruption can occur.
   The reason is this:

   The chip fifo is used not only to contain data, but to contain chip
   status as well.  As a consequence of this, the following could occur:

   Floppy I/O starts.
   HD I/O starts.
   HD I/O is just about finished when floppy I/O finishes and a request
   to start different floppy I/O is made.
   At this point, the floppy changeline status is read from the floppy
   changeline status register, at location 3f7.  If there is data in the
   CMD chip waiting to go to the disk at this point, two bytes of it are
   _removed_ and replaced with the floppy changeline status.  This, of
   course, causes data corruption.

   One person has reported seeing this bug with an Adaptec 1540 SCSI
   controller as well.

   IBM have released a software fix for this in the form of a new
   IBM1S506.ADD; check for PJ19409.ZIP (from ftp-os2.cdrom.com and
   elsewhere) to get it.

2) The Intel Triton PCI chipset (Intel:  8086/32902) (9/4/95)

   Any board which uses the Intel Triton PCI chipset will have, via the
   Triton chipset, support for EIDE built in to the board.  The EIDE is
   busmastering, and apparently allows for throughputs of up to 22 MB/s.
   This particular chipset is reported to be problem-free so far. The
   file triton.exe/triton.zip, available on the major OS/2 FTP sites,
   contains drivers which take advantage of the busmastering
   capabilities of the Triton chipset's built-in IDE controller.  These
   drivers will not work with the (unofficial) release of fixpack 9.
   The Triton chipset has an additional "feature" whereby when using the
   built-in IDE channels cannot be operated independently; both channels
   are either on or off, meaning that you either use two interrupts or
   none.  This allows for faster transfers, though.

3) PC Tech RZ1000  (PC Technology Inc.:  1042/4162) (9/4/95)

   There are two bugs in this chip.  The first has been known for about
   a year, and has a fix in fixpack 5.  Its story is:

   Produces accelerated IRQ.  IBM1S506.ADD actually tolerates this.
   However, when the driver reads (HEX address) 1x7 during interrupt
   processing to clear the interrupt, the chipset puts the status in its
   read-ahead FIFO resulting in data corruption. Intel used this chip on
   their motherboards which they sold to Gateway, AT&T, IBM and others.

   This feature is not mentioned in its chipset errata.

   The second bug was discovered only recently by PowerQuest.  It has
   been the source of much discussion on UseNet.  Here's how the
   now-famous bug occurs:

   HD I/O starts.
   HD I/O is just about finished when some other device interrupts the
   CPU to do DMA (a floppy drive or sound card, for example).  Data is
   still in the IDE fifo.
   The other device finishes its I/O and its status is read from its own
   register.
   The IDE status register is read to check the status of the HD transfer
   (for errors, etc.).  At this point the PC Tech chip _removes_ two
   bytes of the data currently in the FIFO awaiting transfer to/from RAM
   and replaces it with its status.  This, of course, causes data
   corruption.

   (This bug is exactly analagous to the CMD bug described above.)

4) Promise (Promise Technology:  105A/4186) (8/27/95)

   [confirmed/software fix implemented in Warp fixpack 5]

   Promise uses a proprietary implementation to allow 4 drives
   per channel. In normal compatibility mode IBM1S506.ADD
   can only see the 1st two drives per channel.

   In addition their current controller products do not operate properly
   when Set-Multiple support is enabled.  It is therefore necessary to
   detect Promise controllers (which Promise is trying to figure out how
   to do) and, upon detection of a promise controller, disable multiple
   mode support in IBM1S506.ADD.  (Promise has their own drivers for
   their cards.)

5) Winbond (Winbond Electronics Corp.:  1050/4176) (9/13/95)

   This chipset (the W83769F) is used in some Pentium systems to supply
   IDE services.  It is supposed to work well (no reported problems),
   with the exception that the driver documentation is not good for the
   OS/2 driver. Documentation on non-OS/2 drivers is good, however the
   wbideos2.doc which is contained on the drivers disk looks as if it
   was stopped half way.  For example, the documentation does not
   adequately describe command line switches.

   Setup tips:  You must have DOS installed on the machine & be capable
                of either dual-booting or using bootmanager to configure
                the drivers (has to be done in DOS first).

                              Controllers
                              -----------

 BusLogic (104B/4171)   BT-910     BusLogic makes what is apparently a
                                   good, fast, and reliable controller
which has driver support built into OS/2 (via IBM1S506.ADD), or via
their own driver.  The card apparently has an on-board 80286 processor
which supports up to a 16 MB cache (RAM must be purchased separately),
and support for disk mirroring (for drives on separate cables) and disk
linking (for disks on the same cable).

(Buslogic:  104B/4171) (8/27/95)

 DTC                    2130S      This is a single-port controller
                                   which is reported to work well with
Warp when using the latest drivers (available from the DTC BBS).  It
comes with its own drivers for DOS, Windows, and OS/2 (among others),
but will work with IBM1S506.ADD or WDCIDEOS.ADD (the driver from Western
Digital).  It can, apparently, be operated with a 16-bit paddle card
(which will use the ISA bus to grab a second IRQ for the second IDE
channel) for compatibility.  It supports mode 3 operation, multiple
sector transfers, LBA addressing, and ATA rev. 4.0 devices.

(Data Technology Corporation:  107F/4223) (8/27/95)

 Setup tips:  After you've installed the driver, modify its line in
              config.sys to read:

              BASEDEV=DTCIDE.ADD /V /D0:P3 /D0:M16 /D0:L1

              to enable PIO mode 3, multiple (16) sector transfers, and
              LRA addressing.  /D0:M32 may yield better performance.


 GigaByte               GA-0108    This card not only has the IDE
                                   controller (CMD 640), but also has
support for serial, parallel, and game ports (2/1/1) on board.  It is
reported to work well with Warp (the drivers were supplied with the
card).

(CMD Technology Inc.:  1095/4245) (8/27/95)

 Promise                5030*      This card works with or without a
                                   paddleboard, and is reported to work
well with Warp.  Apparently it has options which will allow it to work
with buggy or older PCI hardware (like register config disable, etc.),
which make it a good choice for OS/2.  I don't know if it busmasters or
what modes of PIO it supports.  Note that this board will _not_ work
with the Intel Plato motherboards.

(Promise Technology:  105A/4186) (11/3/95)

 Tekram                 DC290N*    I don't have many specifics on this
                                   card, but it is apparently reported
to work well under Warp with the supplied drivers.  The one report of
success I've had with this board also indicated that use of the supplied
paddle board may not be necessary.

(Tekram Technology Co., Ltd.:  10E1/4321) (8/27/95)

 Tekram                 DC290S     This is the busmastering version of
                                   the DC290N.  I have been told that
the card works well, but that the necessary driver to get CD-ROM support
in OS/2 does not come with the card.  (The same setup gave CD-ROM
support when hooked up to the on-baord EIDE controller on the
motherboard.)

(Tekram Technology Co., Ltd.:  10E1/4321) (8/27/95)

 Tyan                   S1336      This card, like the Gigabyte above,
                                   is based on the CMD IDE chipset and
has support (via the SMC37C665) for serial/parallel/game ports.  I would
not recommend this card, since apparently the documentation contains
errors, and the card is difficult to set up.

(CMD Technology Inc.:  1095/4245) (8/27/95)

 Vision Technologies    QDI6500    This card uses NS16550s for its
                                   serial port and comes with drivers
for DOS, Windows, OS/2 and NT.  It is reported to work well with OS/2.

(IDE controller mfr. unknown.) (8/27/95)

That's what I know.  E-Mail corrections/suggestions and I'll post again.
-- 
Patrick Duffy, duffy@theory.chem.ubc.ca

"Never send a monster to do the work of an Evil Scientist."


