1. There is no such thing as ground.
2. Digital circuits are made from analog parts.
3. Prototype designs always work.
4. Asserted timing conditions are designed first; unasserted timing conditions are found later.
5. When all but one wire in a group of wires switch, that one will switch also.
6. When all but one gate in a module switches, that one will switch also.
7. Every little picofarad has a nanohenry all its own.
8. Capacitors convert voltage glitches to current glitches (conservation of energy).
9. Interconnecting wires are probably transmission lines.
10. Synchronizing circuits may take forever to make a decision.
11. Worse-case tolerances never add — but when they do, they are found in the best customer’s machine.
12. Diagnostics are highly efficient in finding solved problems.
13. Processing systems are only partially tested since it is impractical to simulate all possible machine states.
14. Murphy’s Laws apply 95 percent of the time. The other 5 percent of the time is a coffee break.

Source: Computer Engineering: A DEC View of Hardware Systems Design, 1978, Digital Press, Chapter 1, “Seven Views of Computer Systems”, by C. Gorgon Bell, J. Craig Mudge, and John E. McNamara, Table 5

One day I happened onto a box containing an electronic kit, with components packaged into plastic blocks with magnetic contacts. The blocks could be assembled onto a metal plate to form various interesting circuits, with many examples in the manual. I spent several hours playing with it, then my grandmother found me. She was upset because she had bought it to give me as a Christmas gift, and thought she had hidden it adequately. I didn’t get to play with it any more, and I didn’t receive it as a Christmas gift.

I didn’t remember the name of the kit, and I’d never seen one again until today, though I did get a Radio Shack 100-in-1 Electronic Project Kit a few years later.  A friend got one of the kits with plastic blocks with magnetic contacts recently, and it turns out that it is a Lectron kit.  They are still made and sold in Germany.The Lectron blocks look exactly like what I remember from the basement.    In the late 1960s and early 1970s, they were imported and sold in the US by the Macalaster Scientific subsidiary of Raytheon. The Decode Systems web site has a review from the September 1967 issue of Electronics Illustrated.

There are some other similar products, such as the Elenco Snap Circuits (available from Radio Shack), and for digital logic, Logiblocs.  Bloc-Tronic was similar to Lectron, but was apparently not very commercially successful, as it is extremely rare.

The class I want to take is scheduled for Tuesday and Thursday from noon to 1:15 PM, so I can do it on my lunch break.  There’s also a lab session on Thursday evening.  Yesterday was the first day of class, and there was not a lab.  I’d been checking the online course schedule a lot recently, keeping an eye on the number of seats remaining.  As of Wednesday, there were still seven seats available out of 35, so I thought I’d have no trouble getting in, even if a few extra students showed up.  I was very much mistaken. 

There is light rail service from near my job to a few blocks away from SJSU.  However, the light rail is very slow, so other than at rush hour it is much faster to drive.  I didn’t want to extend my lunch break too much, so I planned to drive.

I left work at about 11:10 AM, to allow plenty of time to get a parking space and find the classroom.  The SJSU North garage, closest to the engineering building, had  a sign indicating that it was full, and to use the garage at 7th and some other street whose name I don’t recall.  I didn’t know where that was, but I figured that I could find it by driving around the perimeter of the campus.  I passed the West garage, which also was full, with a sign saying to use the Park-and-Ride lot.  Finally I found the South garage at 7th and San Salvador; I think that’s the one that sign on the North garage was referring to.  It did not have a sign indicating that it was full.

The South garage has a very narrow lane going up near the center, and an even more narrow lane going down around the perimeter.  It took me about 25 minutes to circle all the way to the top, not spotting any open spaces again, and back down to the exit.  I had less than an inch of clearance on some of the turns.  The posted speed limit in the garage is 5 MPH, and I was driving perhaps 12 MPH peak, slowing to about 8 MPH to look down aisles for open spaces, of which I found none.  Even though I was exceeding the posted limit, someone idiot behind me honked at me several times.

I had no idea where the Park-and-Ride lot was, but by this time it was 11:45 AM, so I didn’t want to spend any more time looking for it.  There were a few available 1 hour parking meters in the area, but that wouldn’t be long enough.  Finally I found a 2 hour meter about four blocks from campus.

I finally got to the classroom at 12:12 PM.  Luckily, the professor wasn’t there yet.  However, every seat was filled and there were about eight students standing.  In a few minutes the professor arrived, handed out the green sheet, and took role.  He was unhappy at how many students were there who had not registered in advance, and asked what our reasons were.  I was the only student wanting to attend through Open University.  Some of the others were retaking the class after failing it previously, and apparently it is not possible to register in advance under that circumstance either.

The big issue seems to be that the classroom has a posted maximum capacity of 40 students.  The professor said he will try to find a larger classroom, but he is not certain that he will be able to get one.  Some students may have to switch to the other lecture session which is on Monday and Wednesday from 1:30 PM to 2:45 PM.   That won’t work for me, so I’ll have to attend the Tuesday class to find out whether I’ll be able to register.

In the future, I’ll take the light rail.  Although it takes longer than driving, it takes less time than driving and parking.  My employer provides a light rail pass, so it will also cost me less out of pocket than parking.