原创 Strange circuit elements: Banana registers

This may come out as a little off-topic, but while I was driving into work this morning, I was ruminating over a certain circuit configuration, which triggered memories of some unusual things I've run across over the years.

In the early 1980s, I was working for a small company in the UK. A couple of the guys were working on a hardware accelerator project. This was a box that would be connected to a standard UNIX computer and would be used to offload and accelerate certain compute-intensive applications.

I was only peripherally involved in this project, but I do recall pouring over the schematics for some reason. (This predated logic synthesis; at that time we captured our designs as hand-drawn gate/register-level schematics.) Deep in the heart of the design, I ran across a register called the LBR, which didn't trigger any obvious associations.

When I asked the team leader what LBR stood for, he replied, "London Bus Register." On further questioning, he explained that this register was used to gather data, and that this data arrived sporadically in clusters. Thus, the LBR register was so named because you can stand around waiting for a bus in London without seeing one for ages, and then a load of them will arrive at the same time.

I've seen the same sort of reasoning applied in other designs. For example, one of my jobs was to write functional test programs to verify printed circuit boards designed by other companies. All I was provided was a "known good" circuit board (which often wasn't) and a set of "known good" schematics (which often weren't). It wasn't uncommon for the schematics to correspond to an earlier or later version of the board.

The point of all this is that, on one of these projects, I found a so-called Banana Register in the middle of the schematic. When I eventually came to chat to the board's creator, he explained that he had named this register based on the fact that the data "came in bunches" (from which we learn that engineers do have a sense of humour—but not a very sophisticated one).

As an aside, did you know that there is a question as to whether a banana is a fruit or a herb? In fact the best answer to this poser is "both." The thing is that a banana itself (the amusingly shaped yellow thing that you peel and eat) is undoubtedly a fruit. It contains the seeds of the plant. However, a "banana tree" is technically regarded as a herbaceous plant (or herb), not a tree, because the stem does not contain true woody tissue.

Come on, you have to admit that you rarely learn nuggets of knowledge and tidbits of trivia like this on any other electronics website, do you? But we digress. Over the years, have you run across any strangely named circuit elements like London Bus Registers or Banana Registers?