Electronics and computer material
Here is just a geneal collection of semi-useful or interesting material, in no real order. A sort of collection of things I have found, or written, or tips, or .. just basicially anything that might be useuful to others, but which does not fit nicely into any other web pages I have. You will also find bits which are humerous to me personally.
Syncronising a pendulum clock to a quartz crystal
Many years ago my wife and I bought an old pendulum clock. It looks nice, but never kept very good time. After looking for a way to improve it, I was made aware of an article: A venerable clock is made highly accurate by equipping it with a quartz-crystal works in the 'Amateur Scientist' part of Scientific America, where the author syncronised a pendulum clock to a quartz crystal. I was hoping to implement this, but somehow I doubt I ever will.
Time interval countersOnline is a scanned copy of the HP 5370B manual, as well as application notes related to this.
RMS PowerThere was an argument on the amps mailing list (not a rare occurance it must be said) about RMS power. Here is a Mathematica calculation performed to compute RMS power. The data is presented in several forms. In order of preference they are:
- Mathematica notebook. That will give you the best view of it, but you must download Mathematica Player to read Mathematica files. If you fancy playing with the equations and graphs, then you can download a demo version of Mathematica. The demo will allow you to do anything for 15 days, but you will be unable to save the files to disk.
- HTML Should display in any browser - how well I don't know
- XML version. You will only be able to look at it, and it might need new fonts installed to see it properly.
HP A3589A 5.5 kW UPSThe HP A3589A 5.5 kW UPS is quite a nice unit, but HP in their infinite wisdom do not make the manaul avaialble, although after a lot of pestering, they did send me a copy. Here is the 257 page manual but there are some other related documents too, which cover some similar Compaq models, software, and network cards. You will have to download the lot and sort it out yourself.
How to cool a Sun SPARCstation 20Here's my ideas on how to cool a Sun SPARCstation 20. The machines are rather an old now (in 2004), but still okay for a web server, or other low end task. This web site is run on a SPARCstation 20.
Installing ipfilter to secure a SunWith all the internet hackers around, it is worth setting up a firewall.
Documents on older UNIX WorkstationsHere's a list of documents of use to owners (like me) of the :
- Dec Alpha
- HP C-series (including the C3000) and J Class
- IBM RS-6000 series
- Sun SPARCstation 20
- Sun Ultra 60
- Sun Ultra 80
- Sun Blade 2000