maintain 'puter batterries

I'm not a hard-core enthusiast:

jsw

No, I have never seen a system where the CMOS memory was supported by the backup power supply. Mostly, that runs either the modem or the net adapter so it can wake the power supply on a net connection or modem ringing event.

Jon

Most Macintosh computers from mid-nineties through 2005 worked that way; don't know for sure about the latest ones. A dead clock battery didn't reset or lose anything until you unplugged your iMac.

Now *that* one would loose the data in just a few milliseconds of no power. :-)

Interesting to see a new page about it.

Enjoy, DoN.

Essentially -- any computer with a "soft" power switch will have

*some* power as long as the cord is plugged into an active outlet. A soft power switch lets you turn power on and off with the same button, with very little force. When turning *on*, it powers up the rest of the outputs of the power supply. When turning *off* it signals the computer to shut down cleanly, and then turns off the main outputs from the power supply.

The power supplies for the ATX style systems are equipped for this. Older systems simply had a power switch between the incoming line power and the power supply, so you had to shut the computer down yourself prior to shutting off the power.

The first machine which *I* had with this feature was the Textronix 6130 -- a small unix box. It looks as though it came from early 1985. Mine was acquired non-functional -- and it turned out to be a fuse hidden inside the power supply. Once I replaced that, it worked fine. I'm very glad that it had that feature, however, because otherwise, until I had discovered the root password on it, I would not have been able to shut it down cleanly.

Enjoy, DoN.

I miss the real switches.

One problem with soft switches / machines - they are always on. That puts them in line with power line issues. A switch is a form of isolation that helps keep some of the bad voltages away.

It also burns power when off. But that is another issue.

Mart> >>> >>