km9p at km9p at
Thu Apr 7 19:18:44 EDT 1994

>From AA2DU:
>Unfortunately, you cannot use the same IRQ for 2 devices simultaneously
>on an ISA board. 

This needs some clarification.  Two devices can share IRQ's if one of the
devices is not polling the IRQ in the first place.  Case in point:  Your
printer ports use IRQ-5 or IRQ-7.  But since you are NORMALLY never receiving
data on a printer port, you can use IRQ-5 or IRQ-7 for your serial ports! 
This is what I have done with all of my computers and have had no problems. 
For the record, I sell computer hardware to computer dealers, and IRQ's are
the least understood animal by so-called computer experts!

Another note:  We used to sell generic serial cards (2 ports) that only
supported IRQ-3 and IRQ-4.  With some help from the expert in Harvard, MA, I
simply cut the trace on the board that went to IRQ-3 and IRQ-4 and jumpered
them to 5 and 7.  It's very easy if you know which ones are which on an AT
bus.  You can find that information at any book store.


Bill Fisher

>From ki4hn at Cybernetics.NET (Jim Stevens)  Fri Apr  8 01:59:57 1994
From: ki4hn at Cybernetics.NET (Jim Stevens) (Jim Stevens)
Date: Thu, 7 Apr 94 20:59:57 EDT
Subject: IRQ's
Message-ID: <9404080059.AA04424 at Cybernetics.NET>

>From KM9P:
>This needs some clarification.  Two devices can share IRQ's if one of the
>devices is not polling the IRQ in the first place.

I'll throw my 2 cents worth into the discussion.  

Bill, I don't understand what you mean by "Two devices can share IRQ's if
one ... is not polling the IRQ ...".  Devices don't poll IRQ lines.  Device
drivers might poll devices in which case the device is normally not
considered to be interrupt driven.  The whole point of interrupts is so
that the device driver does not tie up the rest of the system by polling
the device.

However, I agree that it is not impossible to share IRQ's between multiple
devices on ISA.  It just is more difficult than on EISA or MCA.  The reason
for the increased difficulty has to do with the manner in which devices
indicate to the interrupt controller that they have an interrupt.  On ISA,
IRQ lines are level driven.  The device must raise the IRQ line from a
low voltage to a high voltage and hold it until the interrupt is
acknowledged by the device driver or operating system.  While a given
device is holding the IRQ line high, no other device can signal an interrupt
on the same IRQ, so we have a window for missing interrupts.  How big the
window is depends on the device driver or operating system.  On MCA (and
I believe EISA), interrupts are edge triggered.  The interrupt signal is
latched on a falling edge (I think.  I don't have MCA specs handy at this
time).  Once the interrupt controller has latched the edge another device
could generate an interrupt on the same IRQ.

Now putting on my armor and ducking.

73, Jim Stevens (device driver writer by trade), KI4HN
ki4hn at

>From H. Ward Silver" <hwardsil at  Fri Apr  8 03:55:37 1994
From: H. Ward Silver" <hwardsil at (H. Ward Silver)
Date: Thu, 7 Apr 1994 19:55:37 -0700 (PDT)
Subject: Rating System Announcement
Message-ID: <Pine.3.07.9404071937.D8658-e100000 at bach>

As if we didn't have enough to yak about...but since the K-index is
running about four or five, this reflector is about all that's open!

To the CQ-Contest Internet Reflector
    After watching a lot of thoughtful discussion go by on the 
reflector  regarding issues such as single-multi, geographic 
advantages, regional reporting, scoring, etc. I am pleased to release 
this introduction to our operator rating system.  The time appears to 
be right for the subject and I know we'll receive a lot of comments in 
    I know you'll want the specifics of how it all operates, and that 
will be forthcoming.  But first, I want to present a simple 
introduction that outlines the broad concepts for some public review 
and comment. 
    To give credit where credit is due, Adam, AA7FT, first proposed 
the idea of the Class-based system following the 1990 World Radiosport 
Team Championships.  What has grown from that initial idea is the 
result of a lot of considered review and suggestions from all of the 
rating system authors who have all contributed good ideas. 
    Thanks in advance for your time in review and discussion.  If you 
have specific review comments, please reply to the coordinating 
author's email address below.  I'll summarize them for both the rating 
system author's group and the reflector.  I would expect that general 
comments are welcome on the reflector, however, at the sysop's 
pleasure, of course. 
    I will be attending Visalia with more details of the system 
expecting to hear from many of you firsthand.  It should be a busy 
For the authors group, 73
H. Ward Silver, N0AX
--- cut here ---
Contest Operator Rating System - Introduction
Coordinating Author: H. Ward Silver, N0AX <hwardsil at>
                     22916 107th Ave SW
                     Vashon, WA 98070
Contributing Authors:
    Jack,  WA0RJY <oolon at>
    Adam,  AA7FT  <4146960 at>
    Eric,  K3NA   <ERIC.L.SCACE at>
    Dave,  K8JLF  <hoaglin at>
    Rick,  K7GM   <aoniswan at>
    Alan,  K6XO   <alan at>
    Lou,   K1YR   <amity2 at>
    Rick,  N6XI   <tavan at>
    Randy, K5ZD   <K5ZD at>
    The following introduction is intended to introduce the broad 
concepts of the proposed system to the contest community.  The 
specific mechanics of the system are available in a detailed document 
that is available from N0AX by email on request.  These details have 
intentionally been left out of this general document to avoid 
"information overload".  The system has been through four levels of 
draft review and will continue to be revised and the calculations 
tested on actual contest data before proposing a public 
Background & Introduction 
    As the popularity of contesting has grown worldwide, it has been 
conclusively demonstrated that the rules for most contests result in 
certain geographic and population-related advantages.  Informal 
discussions over many contest seasons have evaluated rule changes to 
"level the playing field" --without success.  Because contesting is a 
worldwide activity, it has become increasingly apparent that ANY given 
set of rules will produce structural inequities among otherwise equal 
    Their highly competitive spirit naturally leads contesters to want 
to have a "universal" set of metrics by which they might measure their 
performance in an absolute way.  Although this remains an elusive 
goal, we have devised an operator rating system that allows the 
individual operator to identify and compete against his or her peers, 
equal against equal.  Though doubtless imperfect, the system addresses 
geographic and population factors. 
    We expect that this system will evolve to accommodate new forms of 
contesting and necessary structural adjustments.  However, like the 
batting average in baseball and rankings in chess, an operator rating 
system, if adequately considered at its inception and administered in 
an unbiased and open manner, should provide a solid basis for growth 
of contesters and the sport of contesting. 
    Briefly, the proposed system sets up three performance classes of 
operators and assesses an operator relative to others in the same 
performance class and the same geographic region.  The measure of 
performance is a numerical Rating that combines both class and 
relative performance within the class. 
    The three classes -- "Competitor", "Expert", and "Master" -- 
formalize relative distinctions that have long been familiar in the 
contesting community. 
    The specific definitions of a region depends on the contest.  A 
feature of the system expands an operator's initial region to include 
a minimum number of peers. 
    After each contest, an operator's Rating may be updated, on the 
basis of the operator's score and the scores of others in that class.  
If the operator performs well enough for long enough, he or she 
advances to the next higher class and the Rating is recalculated 
relative to the new class.  Note that the Rating changes are based 
SOLELY on performance relative to other scores in the operator's 
    An operator may submit scores from different locations, because 
the performance in each contest is judged according to the region of 
the score.  Similarly, an operator may participate in multioperator 
teams or guest-operate at different stations. 
    The Rating becomes a yardstick measuring both coarse (class) and 
fine performance of an operator.  The system establishes a broad peer 
group for an operator while also giving him or her a measure of 
relative performance within that group. 
    An operator's Rating follows him or her throughout their careers 
without regard to where the operations have taken place.  There is no 
need to change either the rules, scoring, or categories of any 
contest.  Similarly, there is no need to attempt to assess the 
potential performance of a station in order to qualify or handicap a 
particular score.  By measuring a score against others in the same 
class and region, the system largely neutralizes structural and 
geographic inequities. 
    At this point, the active contester will be asking, "What's in it 
for me?" and "Is it fair?".  To address the first, the intense 
discussions on geographic advantage over the years are a good example 
of why an operator-based system will be useful.  As solar activity 
hits the bottom of the cycle, the ability to compare one's own 
performance against representative peers becomes ever more important.  
This is also true for consideration of contest categories and scoring. 
    For the Big Guns, this system does away with the perceived need 
for score equalization or handicapping.  The significant achievements 
of these standard-setting men and women will finally have a stable 
framework for recognition.  In addition, ratings may be developed from 
historical data, allowing comparisons to operators of the past. 
    The Medium Gun operators are provided with a measurement of 
performance that charts their progress toward the top level of the 
sport.  They are compared to others of similar ability, allowing a 
clearer view of their relative capabilities.  The achievement of top-
quality performance is clearly rewarded and duly noted. 
    Little Guns everywhere will benefit from such a system as this by 
being compared to each other instead of being left perpetually in the 
dust of the experienced competitors.  New entrants can have their 
modest accomplishments rewarded and receive valuable and timely 
feedback.  The discouragement of fighting up from the bottom of the 
published listings can be lessened by a more appropriate standard of 
    If encouraging activity amongst the newcomers and up-and-comers is 
but one result of a peer-group rating system, then our sport is the 
true winner. 
    As to the second question, we do not pretend that any proposed 
system will be perfectly accommodating of all possible circumstances.  
In the first paragraph of this introduction, we acknowledge that any 
set of rules imposes some arbitrary constraints.  However, if the 
system is "reasonable" and "consistent", then it may be considered 
"fair".  It is our hope that during the review and testing process 
significant flaws will be addressed.  The methods proposed will remain 
understandable and open to the contesting public. 
    The detailed system description will discuss how to calculate the 
Rating, how it changes with each new score, and where the scores come 
from.  We believe that this detailed, concrete proposal addresses the 
basic underlying need for operator peer comparison, without requiring 
changes in any contest rules, handicapping, station assessment, or 
score equalization.  We welcome vigorous discussion.  Send your 
written comments or requests for a draft copy of the detailed system 
proposal to us at the following addresses: 
H. Ward Silver, N0AX - callbook address
Internet - hwardsil at
Packet - N0AX at N7DUO.WWA.USA.NA

>From Don Nutt KJ6TC <kj6tc at>  Fri Apr  8 08:22:36 1994
From: Don Nutt KJ6TC <kj6tc at> (Don Nutt KJ6TC)
Date: Fri, 8 Apr 1994 00:22:36 -0700 (PDT)
Subject: More IRQ's
Message-ID: <Pine.3.85.9404080036.A23698-0100000 at netcom4>

Well as has been stated if more than 1 device is active on the same IRQ,
problems can and most likely occur.  My solution was to hack and old 16
bit controller board for the smaller of the two card edges.  Using a
decent reference guide (any manual, photo copied pages will do) identify
the locations for IRQ 10, 11, 12, 13, 14, and 15.  Note, for those not
aware, IRQ 9 will get you in trouble.  It is cascaded with IRQ 2 (the link
from the first interrupt controller to the second). 

Now you can't use 13 and 14.  Thats the co-processor and the hard drive 
IRQ's respectively.  Now look you have 10, 11, 12, 15 which are referred 
to as reserved.  Reserved for what?  Anything that can access them.

I personally use IRQ's 11 and 12.  I have been looking at 15 in recent 
days.  Oh and yes CT works great.  Try it some time.

For those of you who value your 386, 486, or P5, a new entry in the under
$100 catagory is a 2 port serial card from Sealevel Systems Inc.  The
board features,

	2 Serial ports (DB-9)
	Interrupt  and address selectable (2-5,10,11,12 & 15)
	16550's Standard
	(803) 843-4343

All for $89.00.

I have not tried or tested the boards and know of no one within my group 
who currently have one,  however we are going to order and check one out.

Don Nutt
kj6tc at

>From Earl Morse <E.Morse at>  Fri Apr  8 15:44:08 1994
From: Earl Morse <E.Morse at> (Earl Morse)
Date: Fri, 08 Apr 94 09:44:08 EST
Subject: Contest Clubs in Houston area
Message-ID: <9404080944.A23565 at>

Looks like I'm moving to Houston, TX.

Any information on contest clubs, people, or activities in that area 
would be appreciated.

Earl Morse
e.morse at

>From Peter G. Smith" <n4zr at  Fri Apr  8 12:57:05 1994
From: Peter G. Smith" <n4zr at (Peter G. Smith)
Date: Fri, 8 Apr 1994 04:57:05 -0700 (PDT)
Subject: More IRQ's
Message-ID: <Pine.3.85.9404080405.A328-0100000 at netcom6>

Maybe I'm missing something, but I got a Boca card with two additional 
serial, one parallel and one game port for $15.  True, it doesn't have 
selectable IRQs but there has already been sufficient discussion here 
about how to handle that.  Got it from MEI/Micro Center.x

73, Pete
n4zr at
NOTE: New Address

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