Date   : Mon, 28 Sep 2009 16:28:04 +0100
From   : jgh@... (Jonathan Graham Harston)
Subject: RR09 Photos (Day 2)

Rick Murray wrote:
> Why am I saying all this? Well, *I* might have been inclined to do it
> using a heap of CMOS logic. Or nowadays a PIC. If you want to go to the
 
Have you looked inside a central heating boiler nowadays? When I
helped my dad put his in in 1975, central heating control was
effectively three switches in serial controlling a gas valve:
 
----timer----thermostat----overheatsensor----gasvalve---+
                                                        |
 
After a lot of nursing my boiler died last year and I hed it
replaced. It's a veritable computer in there. The plumber had to
take the PCB back to the supplier because a microcrack on the board
kept causing it to crash on startup. (!)
 
-- 
J.G.Harston - jgh@...                - mdfs.net/User/JGH
There are three food groups: brown, green and ice cream.