Mike Firth wrote:

Getting back into this late, having spent the weekend chasing gasoline
chainsaws on poles, I would like to point out that anyone using a PC older
than a pentium has got to have the basic skills of replacing the back up
battery and working with analog to digital converters for interface or
building such an animal ($200-400). Then programming in a wonderful old
version of C or assembly language or working in Linux/Unix. As it happens,
I have been involved in microcomputers since my January 1975 issue of
Popular Electronics arrived and have worked with single board computers and
assembly language and various PC's (personal computers, not just IBM PC
where IBM stole the initials) for years. But the delights of putting tens
of hours into programming and into accurate analog interfaces to be cheap
have continued to escape me. Of course, so have the delights of being an
interior decorator programming Windows (still using QBasic under the DOS
window in WinXP for utility stuff, very stable unlike Win98)
The amazing choices available in the fractional DIN format (2x2x4") for
about $200 with another $50 or so for thermocouple and SSR and $40 for a UPS
along with the computer interface that allows writing a high level
monitoring program make the effort of a PC just a hobby.
More importantly, all of this is nonsense if one is talking about
controlling gas, where interfacing with the gas and air flow with proper
safety features quickly drives the basic cost up close to $1,000 just in
parts. And most potters use gas or oil because it is easy to heat a large
space with a packaged solution that heats and shuts off using cones that
take in the heating rate - longer for a slow rate, etc.


Just received a CAL9500P today. $178 (EOM price) plus $7 shipping from
PA. Three year warranty and more memory than the end user will ever
need. It's just too easy.

Jack