multiport serial board info needed [spec. re: MAXPEED boards]

[Bruce Himebaugh]

Several weeks ago I posted an article describing a bad experience that our
company had with using a Maxpeed 8 port intelligent i/o card with SCO Unix on
a 386 box.

Within a couple days of posting the article I received a call from the
President of Maxpeed.  He was very concerned about the problems we were having.
He was not angry about the article (or at least controlled himself very well
:-) if he was), but seemed genuine about wanting to resolve the problem.  After
spending some time on the phone explaining the problem to him, he said that
they would begin looking into it.  Our company had talked to a technician at
Maxpeed one time prior to me posting the article to the net and at that time
they had sent us an updated set of device drivers, but that didn't solve the
problem.  Due to the amount of time we had already spent in determining where
the problem was we couldn't afford to call keep calling Maxpeed to try and
resolve the problem; therefore, we had purchased a Digiboard which did solve
our problems.

As far as I know, at the time of this posting, they have not resolved the
problems we were having (nor can they duplicate them), but they did assure me
that they had tested the board with SCO Unix and it did work when they tested
it; therefore, I'm led to believe that it is maybe just the type of machine our
company was using that was the incompatibility problem and not necessarily
Maxpeed's fault.  They have also promised to give us a refund on the board,
which has helped us recoup some of our cost.

At any rate, I am very impressed and pleased with Maxpeed's response to my
article.  They have given me the impression that they are company that cares a
great deal about the customer and they seem very competent in their field.

As I hear more from them, I'll pass it onto the net.

For those who are interested in the details of the problem we had, I have
enclosed a copy of a letter I sent to Maxpeed to try and help them determine
where the problem lies.

Bruce (uunet!ncoast!fmsystm!mrsmouse!bmhalh!bruce)

----------------------- BEGINNING OF LETTER TO MAXPEED ------------------------
    November 1, 1990

    Wei Ching, President
    Maxpeed Corporation
    1180 Chess Drive
    Foster City, CA  94404


    Dear Wei Ching:

    We talked about a week ago regarding the problems our company had with your
    8 port Maxpeed serial i/o card in conjunction with SCO Unix.  I am the
    individual who posted the article on Usenet regarding our experience.

    The purpose of this letter, per our conversation, is to describe the steps
    we took attempting to resolve the problems we were having.

    The primary problem we had was the computer would crash between one and
    five times per day, depending on the hardware/software configuration we
    were using.  At the time of the crash the console would receive a kernel
    error stating that trap 0xE had occurred.  This would be followed by a
    register dump.  Also, at the time of the crash, most of the terminals would
    re-display information that had been typed on them previously in the day.

    When the problem first appeared, we were using the following
    hardware/software configuration:

	- Maxpeed SS-8/XU2 Series 2 Intelligent 8-port Serial Controller
	  (Serial Number: 745028)

	- Maxpeed SS-8/XU2 Device Driver (MAY-15-1990)

	- SCO Unix (version 0 [i.e. first release])

	- Standard Computer Corporation [SSC] (formerly Computer Products
	  United) 386SX Computer containing:

	    - Award 3.11 BIOS
	    - Bus speed running at 10MHz
	    - Default configuration in the extended CMOS setup (except RAM size
	      was changed to 8M)
	    - 387SX Math Co-processor
	    - 8M of 80ns RAM running at 1 Wait state
	    - Chips & Technologies Chip Set
	    - SCC Multi I/O card with 2 serial ports (COM1/COM2) and one
	      parallel port (LPT1)
	    - Magnitronic CGA Video Card
	    - Tecmar QT-150e tape card and tape drive (using IRQ 5, DMA
	      channel 3, i/o address 0x338 - 0x33b)
	    - Western Digital WD1007-WA2 ESDI hard/floppy drive controller
	      using all jumpers on default settings
	    - Miniscribe 9380E 330MB hard drive

    In order to try and determine what was causing the problem, we tried
    switching in and out various components, as well as tried different CMOS
    configurations.  Below is a list of different configurations we tried and
    notations we made during our attempts to resolve the problem:

	- The number of users on the system at the time of the crash would vary
	  from one to five, but there was always at least one user on the
	  Maxpeed card at the time of the crash.

	- When the tape drive was running the crashes seemed to happen more
	  rapidly.  At this point we removed the SCO Unix tape drivers and the
	  tape drive card, but still had problems.

	- We tried using the system with 4M, 6M and 8M of RAM.  It seemed to run
	  okay when using 4M of RAM, but when only using this much memory, our
	  tape drive would not work properly; therefore, we needed to use 8M of
	  RAM.  We also tried the system at 6M of RAM and the crashes still
	  occurred.

	- When running with the MAY-15-1990 device drivers (from Maxpeed) we
	  could make the system crash instantly by typing [ESC][P] or [ESC][7]
	  at any terminal connected to the Maxpeed card.  We verified (using a
	  HP Serial Line Analyzer) that the serial communications were taking
	  place correctly.  We used the following pins in our wiring:

		Shield Ground
		Transmit
		Receive
		Signal Ground
	
	  Since these were the pins being used, this implies that the only form
	  of flow control available was X-ON/X-OFF, which is what we were
	  using.  After installing updated drivers from Maxpeed (Version
	  Sep-27-90) this problem no longer occurred.  Also, the number of
	  crashes per day went down to one or two per day, instead of the one
	  to five that had been happening.

	- We tried using a VGA video card in place of the CGA card.  This
	  didn't help.

	- We tried setting main memory at 1 wait state, as opposed to 0 wait
	  states.  This didn't help.

	- We tried running the bus at 8MHz, as opposed to 10MHz.  This didn't
	  help.

	- We tried using different addressing on the Maxpeed board.  This
	  didn't help.

	- We tried using two different 386SX motherboards.  This didn't help.

	- We tried with and without the 387SX co-processor.

	- We also tried using a straight SCC 386 (i.e. not a SX) running at
	  25MHz (using Award 3.04 BIOS).  This seemed to allow the system to
	  stay up longer between crashes, yet it would still crash.

	- We used Wyse 50 and Link MC5 terminals.

	- The one item we never did change was the hard drive controller, but
	  it had been working previously for six months in another system.

    After trying all the above items, we were still not able to get the system
    to a reliable state; therefore, since we eliminated almost all other
    possibilities, we purchased another intelligent serial i/o card.  We ended
    up purchasing an 8 port Digiboard (model DigiChannel PC/8e).  Since it has
    been installed we have had no problems and are using it with the initial
    configuration I described at the beginning of this letter.  Our conclusion,
    obviously, is that the Maxpeed board was incompatible with the SCO Unix
    (at least running on our hardware configuration).

    In our previous conversations you have indicated that you want to resolve
    this problem and that you would like our help, since you are having
    problems re-creating the error.  We have been very impressed with your
    eagerness in this area, but unfortunately due to the amount of time we have
    already spent we would not be able to justify continuing to work on the
    problem without some form of reimbursement.  Hopefully, this letter will
    give you some insight as to the problems we were having and can help you in
    tracking down the problem, but if you do wish our continued help, please
    contact us and we will work out some type of arrangement.

    In regards to the refund we discussed, I have enclosed a copy of the
    invoice from the vendor from which we purchased the board and our original
    purchase order.  The total amount we spent was $483.00.  Please send the
    refund to:

	A.C.T. Consulting
	1445 Harrison Ave., NW
	Suite 201
	Canton, OH  44708

    Also, please let us know the address to which you wish the Maxpeed board
    returned (and an "attention to" name), and we will immediately send it.

    Again, we greatly appreciate your willingness to help.  Your desire to
    resolve the situation has actually changed our views of Maxpeed, for the
    better.  Within the next week I will be posting a followup article to
    Usenet describing your concern about the problem and that you are
    attempting to resolve it.  If there is anything else we can do to help,
    please let us know.

    Sincerely,



    Bruce Himebaugh
    Senior Programmer

    BMH/dfr

    Enclosure
--------------------------- END OF LETTER TO MAXPEED --------------------------
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Bruce Himebaugh             A.C.T. Consulting, Inc.         Voice: 216-455-1444
   PATHS: uunet!{ncoast,aablue}!fmsystm!mrsmouse!bmhalh!ACT!bruce
          (NOTE: the system name "fmsystm" is with no "e", NOT "fmsystem")
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