# From Gates to FPGA’s – Part 1: Basic Logic

It’s time to do a series on logic including things such as programmable logic, state machines, and the lesser known demons such as switching hazards. It is best to start at the beginning — but even experts will enjoy this refresher and might even learn a trick or two. I’ll start with logic symbols, alternate symbols, small Boolean truth tables and some oddball things that we can do with basic logic. The narrative version is found in the video, with a full reference laid out in the rest of this post.

## Invert

The most simple piece of logic is inversion; making a high change to low or a low change to high. Shown are a couple of ways to write an inversion including the ubiquitous “bubble” that we can apply almost anywhere to imply an inversion or a “True Low”. If it was a one it is now a zero, where it was a low it is now a high, and where it was true it is now untrue.

## AND

Moving on to the AND gate we see a simple truth table, also known as a Boolean Table, where it describes the function of “A AND B”. This is also our first opportunity to see the application of an alternate symbol. In this case a “low OR a low yields a low”

## NAND

Most if not all of the standard logic blocks come in an inverted form also such as the NAND gate shown here. The ability to invert logic functions is so useful in real life that I probably used at least three times the number of NAND gates as regular AND gates when doing medium or larger system design. The useful inversion can occur as spares or in line with the logic.

# Live Now: 2015 Hackaday Prize Worldwide: LA

Events include a ‘Zero to Product’ workshop that will take everyone through PCB design, manufacturing techniques, CAM, soldering, testing, and blowing up caps and releasing blue smoke. You can check out the live stream of that here (or below).

Later on this evening, we’ll be having a few short talks from some LA-area hackers, builders and engineers.

Tomorrow is Open Hack Day, where the Hackaday Design Lab will have tables filled with components, dev boards, soldering irons, and enough blinkey stuff to blind someone. Live stream below.

# Hardware You Might See in a Bar in New York

Our New York City trip for the TechCrunch hackathon is just about wrapped up, and this weekend we’re hosting a hardware hackathon at the Hackaday Design Lab in Pasadena, but there’s still one more event from NYC left to cover: our drink-up in the city.

Our drink-up took over about 90% of the Antler Beer and Wine Dispensary, with the usual, not electronically enabled patrons sufficiently annoyed.

While this meetup was really just a meet-and-greet pregame for the TechCrunch hackathon, and not a proper ‘bring a hack’, that didn’t stop a few people from toting out some very cool hardware. [Katie Fortunato] trucked out a flight data recorder (or an airplane’s black box, painted orange for visibility) that is supposedly from a 747.

This flight data recorder keeps relevant data on a loop of mylar tape. We didn’t crack into that part of the black box, but we did manage to dig into the electronics. Very weird stuff in there; the control electronics have a backplane design, where each card has a connector that’s basically 2 rows of 50 or 75 female pin sockets. These cards aren’t keyed in any way, and they must be placed in the backplane in a certain order. The circuits are extremely simple; just a mix of op-amps, 74- and 54-series logic (no, we can’t figure that one out, either), buffers, and inverters. The latest date code was some time in the early 80s, and all the boards had a conformal coating on them. There’s a weird connector on the outside of the black box [Katie] promises to document on her hackaday.io profile.

Also at the event were a few folks from NYC Resistor, a few people from the IoTGotham meetup, some of the crew from littleBits. Somewhere in the pictures below is a Ms. PacMan/Galaga cabinet. Yes, I tested the bee overflow cheat, it works, but the high score was above 500,000.

# Caption CERN Contest Week 11

Week 10 of the Caption CERN Contest is a wrap folks! Our surprised scientist brewed up a ton of great captions from our great Hackaday.io community. We may never know what exactly is in that keg/carboy, or what the heck is draining into that bucket. Still, it’s probably safe to say that no one has put this much thought into those particular items since this scientist performed his research.

The Funnies:

• “After many decades of hard work, Dr. Milton and his research was moved down into basement after he complained one too many times about his missing stapler.” – [joe_pumpernickle]
• “Parker! Get down here! Ever since that radioactive spider bit you, you’ve crawling up the walls!”-[DainBramage]
• “It rubs the dielectric grease on its relay contacts or else it gets the hose again” -Team effort from [MechaTweak] and [Nick Sayer]

The winner for this week is [airbuckles] with “Meet Dooglas, experimenting with beer brewing, CERN style. Shown here controlling the critical HOP collider.” [airbuckles] won’t need any buckles for his new Robot T-Shirt From The Hackaday Store!

#### Week 11: A double-header!

We’ve got something a bit different for week 11: Two images from CERN’s archives! Both of these images feature a lovely PDP-11 from Digital Equipment in Galway, Ireland. They also feature two CERN researchers. The scientist on the left is wearing typical hacker attire – sneakers, jeans, and a comfy shirt. The hacker on the right went for something which we’re guessing was a bit more stylish back in 1982, but hasn’t quite held up to the test of time.

These scientists must have been doing some heavy-duty number crunching to need a PDP-11. Do you know what that strange hand wired rack of equipment is in the center? Do you have any idea where we can find a pair of harem pants like the woman on the left? Write a caption and let us know!

Add your humorous caption as a comment to this project log. Make sure you’re commenting on the project log, not on the project itself. As always, if you actually have information about the image or the people in it, let CERN know on the  original left CERN image, and original right CERN image.

Good Luck!

# Caption CERN Contest Week 10

We had some great entries in the Caption CERN Contest this week. A huge thanks goes out to everyone who entered.  The jury is still out as to whether the gentleman on the left is a CERN staffer, or a Morlock caught on camera. Our eagle-eyed readers picked out some things we didn’t even notice at first blush – like the strange foreshortening of the “pipe smoking dude’s” right leg. (Yes, he is officially known as pipe smoking dude here at Hackaday HQ). We spotted him again in this image, and he’s in almost exactly the same pose!

#### The Funnies:

• “Billy looked on as the James, the workplace bully, was about to walk in to Billy’s electrified puddle of water..” – [Leonard]
• “This is Bob. Bob made a BAD ENGINEERING MISTAKE. Bob is going to spend some time in THE CORNER. Corners are not easy to find in a ring, so this is Bob’s BAD CORNER.?” – [ca5m1th]
• “In a hole in the ground there lived a hobbit. His name was Boson Baggins and he had a great fondness for pipe weed and protons.” – [shlonkin]

The winner for this week is [Greg Kennedy] with “You call that a moonwalk? Stand back, Edmund, and let me show you how it’s done.”  If [Greg’s] name sounds familiar, that’s because he used some creative web scraping to compile the unofficial stats for the 2014 Hackaday prize. They were pretty interesting, so we featured them right here on the blog. [Greg] will be hacking in style wearing his new Robot T-Shirt From The Hackaday Store!

#### On to week 10!

There’s something for everyone in this image from CERN’s achieves. Gas bottles, chemicals, huge concrete blocks, high voltage wires, and a rather surprised looking scientist. What sort of experiment would require this sort of shielding? What is the photographer standing on? Most importantly, is that a keg of beer hiding under the table to the right?

Add your humorous caption as a comment to this project log. Make sure you’re commenting on the project log, not on the project itself.

As always, if you actually have information about the image or the people in it, let CERN know on the original image discussion page.

Good Luck!

# Caption CERN Contest is a GO for Week 9

Thanks for another week of great entries in the Caption CERN Contest over at Hackaday.io! We still aren’t sure if our CERN staffer is looking at that machine pensively, amorously, or with a bit of confusion, but you all found some great words to go with the image!

The Funnies:

• “Dr. Breman’s early attempts to create the perfect robot woman had some early success, but was later scrapped do to a tragic input/output error.” – Terry Davis
• “You were supposed to be intelligent, my dear. What do you mean by segfault?” –elias.alberto
• “CERN’s pioneering computer dating service didn’t quite work out as expected.” – Nick Johnson

The winner for this week is Stripeytype with the quote seen in the top image of this article. Stripeytype will be sporting a CRT head T-Shirt From The Hackaday Store at their next hackerspace meeting.

We’re not done searching out they mysteries of CERN’s history. Week 9 of the Caption CERN Contest has just begun!

Some of CERN’s experiments take place in the miles of tunnels below their labs in and around Meyrin, on the border of France and Switzerland. It looks like this image was taken in one of those tunnels. It’s definitely an interesting shot. CERN’s documentation for the image has been lost to history, so it’s up to you to explain what’s going on here! Add your humorous caption as a comment to the project log. Make sure you’re commenting on the log, not on the project itself. As always, if you actually have information about the image or the people in it, let CERN know on the original image discussion page.

Good Luck!

# Caption CERN Contest Enters Week 8

The Caption CERN Contest has been going great guns thanks to the community of users over on Hackaday.io. The contest just finished up its seventh week of finding funny captions for images which CERN has in their archives. CERN has decades of great photo documentation of their projects. Unfortunately they don’t know which project each image goes with, or who exactly is in the image. We’re helping them out where we can, by letting CERN know any information we can find on their photos. We’re also having some fun along the way, by giving out a T-Shirt for the best caption each week.

Here are some of the best quotes from week 7

#### The Funnies:

“Are Socks and Sandals acceptable safety equipment for the Demolition Pit? Yes, because these are Kelvar socks and Zylon sandals being testing. Quite uncomfortable, but these feet will survive a close proximity blast.” – [controlmypad]

“Check it out! One tube for each Ninja Turtle” – [OzQube]

“Before the LHC, hunting for the Higgs was much less glamorous.” – [Tachyon]

The winner of course is [Tim] with the featured image at the top of this article.

If [Tachyon] sounds familiar, that’s because he came up with the best caption back in week 6. Runners up for week 6 were:

“Damn Mario Brothers ….. ‘gotta save the princess’ How about watching where you’re going for once. – [Scott Galvin]

“Here at CERN, you don’t get shafted. You get tubed.” – [Rollyn01]

“Thank god the separator caught him. Another 50 meters, and he’d be nothing but quarks.” – [Curtis Carlsen]

Click past the break to check out this week’s image!