On Thu, 25 Apr 2002, Andy Holt wrote:
[mailto:email@example.com]On Behalf Of Allison
Sent: 25 April 2002 15:57
Subject: Re: .I.P. for D.I.Y.
From: Andy Holt <andyh(a)andyh-rayleigh.freeserve.co.uk>
I'll agree - but perhaps the main reason is
that modern components are
almost impossible for the home builder ... and only the odd few
When I was home-brewing computers about 20 years ago the modern components
of the time were
reasonably easy to obtain
reasonably stable for wire-wrap
easy to solder - or use in sockets
adequately documented (usually :-)
if programmable could be DIY programmed rather than needing an expensive
and almost everything worked from a simple 5v supply
You typically have to deal with distributors - little problem for the
experienced, but an obstacle to newcomers
Digikey is not bad for small orders
The edge speed of modern logic is so high that WW is
unlikely to work
You can lower the I/O slew rates on programmable parts
In fact even PCBs now need designing using UHF
techniques for the same
Not all pcbs...
SMT devices - and almost everything nowadays is only
available as such -
are best handled with an expensive soldering station (and BGA devices need
even more expensive equiment).
A simple soldering iron and a hot air gun are adequate for much surface mount
Documentation - though nowadays typically easier to
obtain - is often
Programming devices often needs (one or both of) expensive hardware or
extremely expensive software.
Software for at least Xilinx stuff is free...
You can download the configuration to a FPGA with nothing more than a parallel
port, or a few I/0 bits...
I stand by the "almost impossible" statement above.
Nonsense! Just people who don't want to bother trying...
The one main exception to this black picture is the single-chip flash
micro - such as the PIC family or the 8051 derivatives. But working with
these is more like computer programming than hardware design.
Generalizing on DIY/homebrewing is not good as
exceptions do abound.
Which is why I use terms like "almost impossible"
and "few" rather than