Archive for September, 2008

Free UPS + Free Batteries == Hammond Organ

Saturday, September 27th, 2008

UPS that someone gave me because it didn’t work:

Minus its original batteries, apparently slightly past their prime, which I had to pry out of the case by levering with a big screwdriver:

Overheated gel cell batteries

Plus three-year-old unused batteries from the campus fire chief:

Equals I can play my “new” Hammond organ, which is temporarily in storage where there’s no electricity:

Worth noting:

Cold Start
When the UPS is off and there is no utility power, it is possible to cold start the UPS to power the loads from the UPS’s battery.
Note: Cold start is not a normal condition.
Press and hold the on/test button until the UPS begins beeping.
Release the on/test button during the beeping to start the UPS.

Addendum 29-Sep-2008:

Runtime with a 15W wall wart plugged in was about an hour. Runtime with the Hammond plugged in (after fully recharging) was about three minutes. I guess free batteries are worth what you pay for them . . . but I do now know that the UPS works and is worth replacing the batteries.

Project Idea: Clock with Sliding Hands

Tuesday, September 23rd, 2008

I saw this clock in a catalog last night:

I like 24-hour clocks; and I’m a computer geek, so I use 24-hour time for its unambiguity. And I like the visuals of this clock — but it’s functionally useless and/or made for idiots, as the 24-hour-ness of it is strictly cosmetic. It gives you no idea whatsoever whether it’s currently 07:00 or 19:00; it just has both numbers painted on, and the hour hand will point in the general direction of both.

How ’bout a clock with a face like this — numbers spiralling inward — and an hour hand that slides back and forth end to end across its axis as it turns, so that the end of the hour hand is always touching the marking for the correct hour? At 07:00, the hour hand is still slid most of the way to the outside of the clock and its end touches the 07; at 19:00, the hour hand has withdrawn further across the center of the clock and its end touches the 19.

Of course it’d need to be done with gears; I’m not talking about an LED or LCD clock.

Interesting Bits of Old Motherboards

Monday, September 1st, 2008

I’m salvaging parts from some very old, dead (leaking capacitors and batteries, corroded components) PC motherboards and found some interesting bits.

ICs inside IC socket

14-pin ICs mounted inside a 40-pin IC socket (that was populated). Very cute. Makes me want to do something extra-naughty, like mount an SMT IC underneath a DIP (no socket needed).

18/20-pin IC sockets

18/20-pin IC sockets, so you could pick which size L2 cache chips to install. Although it’s not obvious from straight above, these are not hacked together out of regular sockets — they were manufactured this way.

I found them on two different vendors’ boards, and I had never noticed them when I was servicing PCs during that era. I guess it solves the problem of knowing which end of a regular 20-pin socket to stuff an 18-pin IC in; or maybe the 18-pin and 20-pin ICs didn’t have compatible pinouts.

Novell 8088 motherboard with onboard ethernet

A Novell 8088 motherboard with onboard ethernet. Various other curiosities are visible in the large version of the picture, but worth noting is the “PC TERM. BIOS,” which leads Joel to question whether this was a dual-function PC and network terminal.