I have switched to FreeBSD after spending a few months banging my head against OpenBSD. OpenBSD is a nice O.S., and I really didn't want to switch, but now that I'm trying FreeBSD, here are some first impressions of the differences.
Reasons to Choose FreeBSD
Would you like clear, well-written user documentation, instead of curt citations of man pages, and faq entries? You want FreeBSD.
Would you like to experiment with hosting MS-Windows (or Linux, or another BSD, etc.) as a guest O.S. in a virtual machine, right out of the box? You probably want FreeBSD.
You have an older machine with only 1/2 gig of ram, and you think you should be able to run firefox without hitting the swap file? Free is the O.S. for you.
You have an older computer that runs at just under 1 gighz, and you think it's reasonable to expect an O.S. to deliver decent performance from that? You need FreeBSD
You've invested a lot of time switching from MS-Office to OpenOffice and you don't want to have to now learn the latest other OTHER office suite? Definitely, you want FreeBSD.
You're an experimenter who wants to install BSD on your Raspberry Pi? Most seem to agree, FreeBSD is a better fit for you.
Reasons to Choose OpenBSD
You think PF (Packet Filter) is a really cool piece of software and you want to run it? OpenBSD is for you.
And Now, for Something Completely Different
Are you a masochist who is excited by the idea of being beaten to a pulp, and left naked in the middle of the ethical, legal, and financial mine-field that is the GPL?. . . You want linux.
An experimenter in a facebook group that I'm a member of put up the following schematic. They asked for group members' help to give a simple explanation of the circuit. I've put the schematic here, so that I can give some feedback with a little space and some links.
The above circuit is a fluid level meter that converts the level in the container on the left into a single-digit number, from 0-9 on a seven-segment display. In this case, 0 (zero) represents the lowest level, and 9 (nine) is the highest level.
Finally got the intensity problem fixed on the new (used) scope. It was a couple of bad diodes and some supporting components. I tried to get the originals, but that was not going to happen in any decent time frame.
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Trusty ol' 1N4004 diodes don't have the fancy low-capacitance, high-switching-speed of the original diodes, but they have more than enough reverse voltage and power handling. . . Hmmm. . . would they work? YES! The scope is all calibrated now, and works like a charm. Now that the brightness works I can see what the whole Inten'D thing is for (my old Heathkit scope didn't have delayed triggering). Pretty cool!
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Summary: $80 + a little elbow grease = 35 MHz Dual Trace Scope
The $80 price includes the shipping cost!
Model: JDR Instruments 3500
Found and downloaded a free manual (images scanned into a PDF). It was needed for the schematics to fix the intensity problem, but it also included the calibration procedures.
The guy who sold it was a bit of a sleaze bag (imo). He said, directly, that he wasn't aware of any problems, though he took a picture of it with the traces showing pulses. To me, that means he would have fiddled with the focus and intensity controls and seen that the intensity control had no effect.
So, it had a problem with the intensity that turned out to be two different diodes in the intensity circuit (go figure).
Now I've got a scope that probably cost >$1K new, and would cost $200-500 used in good working condition today. Not too shabby.
It came in the mail yesterday. A used, JDR Instruments, 35 MHz, dual trace scope for $80.00 (Shipping included) on eBay!
It had two obvious problems.
No horizontal positioning — I was able to fix that by following wires and traces back from the front panel.
The brightness is at full all the time — not able to fix that without schematics.
I spent a bit of time with it, and while it needs some calibration, I haven't been able to find anything else wrong. Also cool, it has a Z input in the back, which means I'll be able to play asteroids on it
Finally managed to slosh enough junk around to clear the table in the foreground and then clean off the old workbench. The last time it was out from under a quarter inch of dust you needed a t-square to produce PCB layouts (see it there). The old scope smoked out as soon as I turned it on. It smelled up the whole basement.
All the bread-boarding sockets had been left completely uncovered under all the dust and in the dampness for the entire time. Nonetheless, I decided to assemble a small, experimental, logic circuit on the old breadboards and surprisingly, the circuit worked!
So, what does it mean if, while other guys are spending time and money building man-caves, you start building a maker cave? Well, you might just be a geek my friend.