The General Approach to Computing - A Ramble

Warren Wolfe lists at
Thu Apr 23 15:04:08 CDT 2009

Subject was:Re: AppleColor RGB Monitor (IIGS) help?

Tony Duell writes:

    The most basic test is to remembner that a transistor has 2 diode
    junctions, one between base and emitter, the other between base and
    collector (no, you _can't_ make a transistor from 2 diodes!). So you
    can test each of those junctions as a diode using either an analogue
    ohmmeter, or more likely these days the diode-test range of a DMM.

Well, thanks, Tony.  This is the first time I was confident I had 
exactly the right info to help another list member diagnose a problem in 
a couple of months, and you go and spoil it.  Sheesh!  (Just kidding...  
mostly.)  Complicated questions on specific equipment from companies 
whose equipment I have not used makes trying to help out on this list 
significantly more difficult.

FWIW, I almost always learn something from your posts, except in those 
instances where your post confirms what I already knew, and gets there 
before I even read the question.  You're quite an excellent resource for 
the list, and I heartily approve of your approach, in terms of being 
able to fix one's own equipment.  That USED to be a necessary part of 

Back in the day of my IMSAI 8080 and CP/M 1.3, I was approached by a 
friend (since I had a computer, and they were magic) to keep a mailing 
list, with extra information, for a 500+ member newsletter.  The 
director would keep track of changes, and come over to my place to make 
the changes on the list, and run the program I wrote to print the labels.

One month, the director came over and caught me by surprise, it not yet 
being the very last day possible to print the labels.  I invited him in, 
and expressed my willingness to get started.  He began to laugh.  I 
asked him why.  He said "Don't you know what you just said?  I asked if 
you were ready to add some names, and make some changes to subscription 
dates, and you replied 'Fine, I'll go get my soldering iron.' "

That's not as odd as it sounds, and, no, it wasn't a hard-wired 
program.  My IMSAI had 15 boards of 4K each of 2102 memory, and 
replacing chips was about an hourly task.  Heck, I even wrote my CONST 
(console status routine for CP/M) such that if there was no character 
ready, it would test one memory location before returning.  Made 
interesting patterns on the LEDs.)  Computer clubs were places people 
went to get soldering tips as much as discuss programming, despite 
having Gordon Eubanks (Symantec, Basic-E, CBasic) as a member, and 
frequent appearances by Gary Kildall (author of CP/M) in the club, the 
software discussions were always for AFTER people had their machines 

Sorry for the digression.  The point being that it used to be MANDATORY 
to be able to fix one's own computer, lest one become dependent upon the 
pity of others to get anything done.  I find that approach still useful 
to some extent, and I've always been able to fix my own machines at 
least as well as the (generally) trained-chimp-level techs at local 
fix-it shops.  That many orders of magnitude of complexity have come and 
gone since the IMSAI days are good, in terms of what one's money will 
buy today, but bad in that one is much less likely to be able to fix 
one's own equipment to component level.  It's not as satisfying to say 
"Hmmm.  You need a new video card" as to hold up the offending 
transistor and cackle.   Or is that just me?

I guess, to sum up this ramble, Thanks, Tony!  I enjoy reading your 
posts, and appreciate your mind-set on the issues.



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