Today’s vintage entry is rather cute:
Today’s teardown subject is another vintage find: a 1974 Casio Personal-Mini.
Today’s topic is somewhat unique- a vintage optical mouse, made in the days when it was not very trivial. It’s not like you can just slap a camera in and have it take pictures to figure out where things move. In the old days you had to actually design it, maybe even using some 2N3906 and 555 timers as we’ll find out. Let’s start with unboxing (pardon the masking tape holding things together)
This one has been sitting since the summer- it took a while to get all the rain to evaporate from the inside! When I grabbed the pour fella, it had water up to the mirror.
Today we have two tiny multimeters to take apart and see what we can learn from how their designs progressed:
On the left is Hioki 3217 and on the right – Beckman DM78
Another addition to my growing collection of vintage multimeters is this Weston Schlumberger Model 6000 meter from the mid 1970s
The meter was listed as in almost like new condition except for a spot on the front panel. It came with (very rubbery) test leads and an actual printed user manual- a rare thing these days.The Ebay posting was worded very carefully to never mention whether the thing actually works, so I figured it did not really matter. If it does not- teardown turns into repair attempt and either way we learn something new. Continue reading
The latest addition to our vintage collection is a Keithley 130A handheld DMM from the mid-eighties.Keithley is not well known for its handheld DMMs, or at least I’ve never heard of them. It’s a 3.5 digit 0.25% instrument made in mid 1980s
Another ebay find- a vintage Keithley 172 multimeter. The datecodes on the parts range from 1978 to 1984, placing the final assembly somewhere in mid-1980s. It seems fully functional, but could use a bit of a calibration to regain its past precision.