9 May
2016
9 May
'16
2:36 p.m.
I figure I'm good for about eighty hours or so of reading and fooling
around with electronics before I'll want to move onto a different hobby
for a while (I rotate through a whole bunch). That's my normal MO. So, I'm
wondering what kind of skills I could build with that time, once I get
started. I'd love to hear if anyone has suggestions for how to use my time
wisely to learn skills that would be most useful for working on older
machines (mid 80's to late 90's is my focus as far as a hardware
bandpass).
Here's what I (think) I know now:
- Basics about electricity. Ie.. Ohms law, power vs frequency, etc..
- I understand basic physics ("A" in 100-level college course and two
years of high school physics, too). I actually had an excellent teacher,
too!
- I used to do math to about a 300-400 level, but now I'm at a 100-200
level (I can still do most algebra II, some trig, and a few other bits).
- I understand what most analog components do (resistors, capacitors,
diodes, etc..). I can run a volt-meter, and super-basic operations with
an analog scope (checking test points and that kind of simple crap) . I
also have a rudimentary rig for soldering etc...
- Since I'm a coder, I understand boolean logic (which I hope would help
with ICs).
- I took a digital electronics course in college. However, it was pathetic
and it's all gone now anyway.
I've spent most of my technical energy learning coding and sysadmin
skills, not hardware. I'm still interested in it, though. I'm most
comfortable with self-teaching via projects. Any that you folks would
recommend (even if they are for kids, I don't mind, I'm not proud) I'd
love to hear about them. Books, project kits, etc.. My goal would be able
to understand 40% of what is happening on an Amiga 500 or that level of
machine. If I could do that.... wow. fun. cool. Plus I bet I could repair
many more items/problems than I can today.
-Swift
9 May
9 May
8:40 p.m.
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Swift
Griggs
Sent: 09 May 2016 22:37
To: General Discussion: On-Topic and Off-Topic Posts
<cctalk at classiccmp.org>
Subject: "Retro Repair" key electronics skills?
I figure I'm good for about eighty hours or so of reading and fooling
around
with electronics before I'll want to move onto a
different hobby for a
while (I
rotate through a whole bunch). That's my normal
MO. So, I'm wondering
what kind of skills I could build with that time, once I get started. I'd
love
to
hear if anyone has suggestions for how to use my time
wisely to learn
skills
that would be most useful for working on older
machines (mid 80's to late
90's is my focus as far as a hardware bandpass).
You don't list being able to repair power supplies below. I would thoroughly
recommend that as a valuable skill for older machines. I don't have any
great skill there either, what I do know has come from people on this list
very generously helping me out.
Regards
Rob
Here's what I (think) I know now:
- Basics about electricity. Ie.. Ohms law, power vs frequency, etc..
- I understand basic physics ("A" in 100-level college course and two
years of high school physics, too). I actually had an excellent teacher,
too!
- I used to do math to about a 300-400 level, but now I'm at a 100-200
level (I can still do most algebra II, some trig, and a few other bits).
- I understand what most analog components do (resistors, capacitors,
diodes, etc..). I can run a volt-meter, and super-basic operations with
an analog scope (checking test points and that kind of simple crap) . I
also have a rudimentary rig for soldering etc...
- Since I'm a coder, I understand boolean logic (which I hope would help
with ICs).
- I took a digital electronics course in college. However, it was pathetic
and it's all gone now anyway.
I've spent most of my technical energy learning coding and sysadmin
skills,
not hardware. I'm still interested in it, though.
I'm most comfortable
with
self-teaching via projects. Any that you folks would
recommend (even if
they
are for kids, I don't mind, I'm not proud)
I'd love to hear about them.
Books,
project kits, etc.. My goal would be able to
understand 40% of what is
happening on an Amiga 500 or that level of machine. If I could do that....
wow. fun. cool. Plus I bet I could repair many more items/problems than I
can today.
-Swift
10 May
10 May
7:16 a.m.
- Since I'm a coder, I understand boolean logic
(which I hope would
help with ICs).
While it's an understandable point of view, especially for a coder, not
all ICs are digital logic - and even for those that are, understanding
non-digital-logic aspects of them can be useful. (I built an EPROM
reader out of SSI TTL, and found it always read the last octet as FF
even in cases where I knew better. Turned out I forgot to connect the
ground pin on the EPROM to circuit power ground; provided at least one
input was low, it powered the chip through the input protection diodes,
but when all connected pins were high - and all the non-address inputs
that weren't high were tied to the ground pin - then all outputs
perforce were too. But that failure mode would have been inexplicable
if my mental model of the thing had been an ideal logic device.)
/~\ The ASCII Mouse
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7:53 a.m.
On Tue, 10 May 2016, Mouse wrote:
While it's an understandable point of view,
especially for a coder, not
all ICs are digital logic - and even for those that are, understanding
non-digital-logic aspects of them can be useful.
Right now I've started looking at the textbooks & lessons here:
http://www.allaboutcircuits.com/textbook/
Volume IV is about digital. However, I'm finding quite a few topics in the
previous books are things I'm not strong in, either. I get the feeling one
needs to have quite mastered analog before moving to digital. So, I
completely believe you.
(I built an EPROM reader out of SSI TTL, and found it
always read the
last octet as FF even in cases where I knew better.
Once I brush up on theory a bit, I'll have to find me a project like that.
-Swift
7:59 a.m.
- Since
I'm a coder, I understand boolean logic (which I hope would
help with ICs).
While it's an understandable point of view, especially for a coder, not
all ICs are digital logic - and even for those that are, understanding
non-digital-logic aspects of them can be useful. (I built an EPROM
8:25 a.m.
On Tue, 10 May 2016, tony duell wrote:
Remember one of Don Vonada's laws 'Digital
Circuits are made from
Analogue Parts'
That's an interesting saying.
So what appears to be a solid power or ground
connection may have
different voltages along it.
Those types of nuances and inconsistances are always frustrating but I
understand it's the nature of working in the real world, rather than
software. :-)
Getting back to the original request, my main worry is
the 80 hour time
limit.
Oh, that's just about the amount of time it takes before I rotate to the
next hobby for a while. However, I find that the better I get a things,
the more I enjoy them and then the rotations get longer for those hobbies.
I just know that eighty hours is about as much as I can spend just doing
pure learning before my mind needs a break for a while. It's not really a
"limit". It's more my "bite size".
I am far from being the most knowledgeable person
here, and perhaps I am
a very slow learner, but I must have spent over 80 _thousand_ hours
learning electronics and related subjeccts. And FWIW I am still
learning.
I hear ya. There is nearly infinite depth there, no doubt. I just want to
build up to a basic skill level that gets me functional in a few areas I
care about.
-Swift
8:27 a.m.
Remember one
of Don Vonada's laws 'Digital Circuits are made from
Analogue Parts'
That's an interesting saying. 
12:33 p.m.
tony duell wrote:
Another of Don Vonada's laws is 'There is no
such
thing as ground'.
My father is a civil engineer. When I was a little
kid, he was in the US Air Force. We would frequently
go to the runway snack bar, get ice cream and watch
the B-52s do "touch-and-go" landing practice. The
plane's wings would "flap". It raised the hair on
the back of my neck. My dad explained that, if they
didn't flex, the wings would break off. After a
while, I understood, intellectually. It still "gave
me the willies". Later I had a similar experience
when I was with him in a tall building and realized
that it was "waving in the wind". Same thing, if it
didn't flex, it would fall.
The other is that, as I said before, any ground
connection has impedance (it's the inductance that
is troublesome normally) so that points (say IC pins)
that are shown as grounded may actually have a
voltage difference between them.
If I think about it too much, this gives me the
willies, the same way.
Bill S.
3148
days inactive
3149
days old
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