24 Dec
2007
24 Dec
'07
8:59 a.m.
Subject: Re: Re : 2N2/256-BSCP
From: Dave McGuire <mcguire at neurotica.com>
Date: Mon, 24 Dec 2007 11:08:01 -0500
To: "General Discussion: On-Topic Posts Only" <cctech at
classiccmp.org>
On Dec 24, 2007, at 3:56 AM, ard at p850ug1.demon.co.uk wrote:
Only if you don't spend hours looking for the transistors that flew off
the end of your tweezers :-).
Oh, SOT23s are easy to deal with. 01005-size components are the ones
that just disappear without a trace.
Actually the Accutron watch used a very small tansistor to excite the
tuning fork the package was a three legged item of .095" diameter
and 0.130 long with the 3 leads exiting the end. I've had 4 of them
in my parts collection for over 35 years looking for a small project.
Small existed back then. Keep in mind the Apollo Guidence computer
is over 40 years old and that was 3input nor gates!
Transistor computers were near their end 40 years ago with ICs making
inroads. So comments on predominently transistor computers really
have to point to prior to around 1968ish and thats within a week of
40 years ago. The interesting transistor machines are in the time
frame of TX1 through PDP-8 roughly 1957 to 1967 (someon can fine
tune those days).
Anywho the dividing line is around 1963 and prior for germainium
transistors (grown and diffused junctions types) and after then for
silicon devices with superior characteristics.
Allison
Given that there's a limit on the number of
transistors, I don't
see what
advantage using SOT23s would give you.
It'd be easier to assemble. My point is that while SOT23s didn't exist 40
years ago, there is no
real
reason to prohibit them in a project like this. Limit the number of
transistors, sure. Insist on an architecture that could be built 40
years
ago, sure. But should the use of a storage 'scope to debug the thing be
prohibited too, on the grounds that hobbyists 40 yrars ago were lucky
to
have _any_ 'scope? Do you prohibit writing simulators for the
transistorised machine, on the grounds that 40 years ago hobbyists
wouldn't have had anything to run them on?
I'd have to agree.
-Dave
--
Dave McGuire
Port Charlotte, FL