SBC6120 (a build-it-yourself PDP-8 clone) grammer checked

Tony Duell ard at p850ug1.demon.co.uk
Wed Jun 14 20:42:23 CDT 2006


> 
> On 6/14/2006 at 6:30 AM dwight elvey wrote:
> 
> >I did my first short wave receiver from an article in "Boys Life".
> >I use a piece of ply wood and borrowed a neighbors router
> >to make channels for all the wires and screws. It didn't
> >need the corner feet :)
> 
> When I was a boy, the local branch of the public library had an 1890's book
> titled "Harper's Electrical Book for Boys" (IIRC).  It showed how to make

I have it (well, I would :-)). IIRC, the author worked for Edison for a 
time.

I think it's beem reprinded by Lindsay Books (or at least was for a 
time). So it may not be too hard to find.

> everything from telephones to dynamos and lead-acid secondary cells and
> carbon-arc lamps.  It had directions that said things like "Go to a
> blacksmith's shop and have him fabricate the following part" or "Oil of
> Vitriol can often be obtained from your local illuminating gasworks."  

Some of the chemicals suggested for electorplating (and to a lesser 
extent for batteries) were downright lethal!.

> 
> I really liked that book, even though I never built anything from
> it--blacksmiths were in short supply at the time--and I never did find my
> local gasworks.  I wonder if electronics will get to the point of some

Well, 'Oil of Vitriol' is, IIRC, sulphuric acid, amd that is still not 
too hard to get. And there are books on blacksmithing, so I guess you 
could even do that part yourself if really determined! More seriously, a 
lot of the metalwork described in 'Harpers electricing book for boys' can 
be done mroe easiy with more moden tools (like an engineer's lathe for 
screwcutting).

> young lad wondering where on earch one would find a 74LS00 or 2N2222 or
> 1N914 or even "hookup wire".

I can easily imagine TTL disappering, but I think the TUPs and TUNs [1] (as 
Elektor used to call them) will be availalbe.

[1] Transistor, Universal, PNP, Transistor Universal NPN. Basically, 
generic trnasistors. Elektor used to publish circuits with trnasistors 
labelled TUP and TUN (and diodes labelled DUG (germanium) and DUS 
(silicon), along with quite long lists of components that would work in 
all such positions.

-tony



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