Not everybody will agree with the concept of "buy
crappy tools, so that
My ears are burning :-)
you HAVE them, and then upgrade". The wording
needs to be fine-tuned to
reduce the offense to the sensibilities of those who appreciate fine
tools. 40+ years ago, when I replaced my generic 10mm socket and
generic 1/4-20 and 6mmx1.0 taps with Snap-On, I knew that eventually I
would have a "complete" set of quality tools, but if I were to have
STARTED with a full set of quality, I couldn't have gotten started.
I appreicate the problem. The sort of socket set I would _like_ to buy,
if I was buying one now, is over 10 times the price of a 'crappy' one.
However, there is a case to be made, I think, for buying the few tools
you need -- and getting high quality ones -- rather than buying a large
set of cheap tools.
FOr example, you mentioned taps. I tend to buy only the sizes I need, anf
get good ones, rathen than buyign one of the cheap imported srts with
plenty of sizes I don;'t need and made from 'steel' that appears to
actualyl be cheese...
More needs to be added about appropriate projects to learn with,
I learned soldering with some Heathkits, and then later populating a
couple of generic blank XT motherboards with Augat sockets. I don't
think that such blank boards are available any more.
What are some good sources for beginner projects?
There are sill pletny of kits out there -- Velleman, for exmaple. But
they are gernally not as 'complete' as Heathkits. You find that thigns
like th box, mountign hardware, connectors, etc are not included. Often
you get the PCB and the components to put on it, and nothing more.
They are also less educational as regards electroncis than older kits.
Many now incldue a programemd microcontroller and you do nto get the
source code. SO you cna't really understand what it's doing. Unlike a
circuit made from discrete transistors (or valves) where you can
understand what is going on.
as I said, assembly kits is a good way to learn to use the tools, but
it's not all you need to be able to do.
Who here can write out some basic steps for how to check out a "dead"
It depends -- a lot -- on the computer. I've writen a set of articles for
HPCC (and the only way to get them at the moment is to join HPCC, sorry!)
on repairign the HP9800 calculators. I do include an intital checkout
procedurte, but must of it would not apply to other machines.
That said, there are some basic tests that youy do on just aobut any
1) Check the power supplies. Cheak the voltages nad check them for
ripply. Power supply problems are suprisingly common, and no computer
works porperly if it's not powered properly
2) Check the processor clock signal.
3) Check the reset signal. Make sure the processor isn't being held reset
(or worse that it's not being reset at mains frequency due to a problem
with the power-OK circuitry, yes, that's csuprising common too).
3) Check if the processor is doing anything. Is it attempting to read
memeory, for ecample
4) Cehck all data and adreess lines for activity. ALl data lines should
be toggling,. the low-order address ones shoudl be too. It's posible it's
(correctly) running a small routine and thus the high order address lines
might be steady
5) Check to see if it is acessing the firmware ROM
6) If you have a logic analyser, grab the data and address buses and see
what it is acutally trying to execute. Does it make sense? Do jumps cause
the address to change in the right way?
People like us aren't going to stick with a rigid
structure. By high
school, my projects were becoming orthogonal to my teachers' lesson plans.
Yo uand I have a lot in common...