The Ursa Major Space Station SST282 is a dinosaur of a digital reverb. Okay, so maybe 1978 isn’t ancient yet, but it is getting to the point where one has to worry about the possibility of component failure. At least that’s what [Obsoletetechnology] thought when they created a backup of its memory contents.
As can be seen from some of Hackaday’s previous articles, a part does not have to be an older one to fail. However, there is no such thing as being too paranoid when it comes to older parts reaching their lifetime. Especially when there is valuable memory involved. Each bit of PROM memory is locked by a fuse on its location grid to store permanent data. To be able to read this and collect the respective data, a Raspberry Pi 3 PROM reader was created.
The SST282 uses 3 TTL-level 74xx series Schottky PROM memories on board that hold RAM lookup tables. In the case that these failed, all of the subsequent information would be lost since there are no surviving memory dumps online. Fortunately we are interested only in gathering their contents, so the PROM reader schematic is fairly rudimentary. The chip’s address and data buses connect to a Pi’s GPIO header, and the only other thing to note is a 74LS541 TTL level shifter that converts the Pi’s 3.3V output to the PROM’s 5V TTL level.
Continue reading “Blast From the Past with Space Station PROM Reader”
Usually, repairing a device entails replacing a defective IC with a new one. But if you’ve got young eyes and haven’t had caffeine in a week, you can also repair a defective chip package rather than replace it.
There’s no description of the incident that resulted in the pins of the QFP chip being ablated, but it looks like a physical insult like a tool dropped on the pins. [rasminoj]’s repair consisted of carefully grinding away the epoxy cap to expose the internal traces leading away from the die and soldering a flexible cable with the same pitch between the die and the PCB pads.
This isn’t just about [rasminoj]’s next-level soldering skills, although we’ll admit you’ve got to be pretty handy with a Hakko to get the results shown here. What we’re impressed with is the wherewithal to attempt a repair that requires digging into the chip casing in the first place. Most service techs would order a new board, or at best solder in a new chip. But given that the chip sports a Fanuc logo, our bet is that it’s a custom chip that would be unreasonably expensive to replace, if it’s even still in production. Where there’s a skill, there’s a way.
Need more die-level repairs? Check out this iPhone CPU repair, or this repair on a laser-decapped chip.
If you’ve ever wanted to open up an IC to see what’s inside it, you have a few options. The ceramic packages with a metal lid will succumb to a hobby knife. That’s easy. The common epoxy packages are harder, and usually require a mix of mechanical milling and the use of an acid (like fuming nitric, for example). [Robert Baruch] wanted to open a fully ceramic package so he used the “cooler” part of a MAP gas torch. If you like seeing things get hot in an open flame, you might enjoy the video below.
Spoiler alert: [Robert] found out the hard way that dropping the hot part isn’t a great idea. Also, we are not sure what the heat does if you want to do more than just inspect the die. It would be interesting to measure a junction on the die during the process to see how much heat actually goes to the device.
Continue reading “Popping the Top of A Ceramic IC”
[Ken Shirriff] is no stranger to Hackaday. His latest blog post is just the kind of thing we expect from him: a tear down of the venerable 8008 CPU. We suspect [Ken’s] earlier post on early CPUs pointed out the lack of a good 8008 die photo. Of course, he wasn’t satisfied to just snap the picture. He also does an analysis of the different constructs on the die.
Ever wonder why the 8008 ALU is laid out in a triangle shape? In all fairness, you probably haven’t, but you might after you look at the photomicrograph of the die. [Ken] explains why.
Continue reading “8008 Exposed”
[Ken Shirriff] has seen the insides of more integrated circuits than most people have seen bellybuttons. (This is an exaggeration.) But the point is, where we see a crazy jumble of circuitry, [Ken] sees a riddle to be solved, and he’s got a method that guides him through the madness.
In his talk at the 2016 Hackaday SuperConference, [Ken] stepped the audience through a number of famous chips, showing how he approaches them and how you could do the same if you wanted to, or needed to. Reading an IC from a photo is not for the faint of heart, but with a little perseverance, it can give you the keys to the kingdom. We’re stoked that [Ken] shared his methods with us, and gave us some deeper insight into a handful of classic silicon, from the Z80 processor to the 555 timer and LM7805 voltage regulator, and beyond.
Continue reading “Ken Shirriff Takes Us Inside the IC, For Fun”
There’s nothing more freeing than to be an engineer with no perceptible budget in sight. [BrendaEM] walks us through a teardown of a machine that was designed under just such a lack of constraint. It sat inside of a big box whose job was to take silicon wafers in on one side and spit out integrated circuits on the other.
[BrendaEM] never really divulges how she got her hands on something so expensive that the engineer could specify “tiny optical fiber prisms on the end of a precision sintered metal post” as an interrupt solution for the wafer. However, we’re glad she did.
The machine features lots of things you would expect; pricey ultra precise motors, silky smooth linear motion systems, etcetera. At one point she turns on a gripper movement, the sound of it moving can be adequately described as poetic.
It also gives an unexpected view into how challenging it is to produce the silicon we rely on daily at the ridiculously affordable price we’ve come to expect. Everything from the ceramic plates and jaws that can handle the heat of the silicon right out of the oven to the obvious cleanliness of even this heavily used unit.
It’s a rare look into an expensive world most of us peasants aren’t invited to. Video after the break.
Continue reading “Silicon Wafer Transfer Machine Is Beautifully Expensive”
The first integrated circuits weren’t tiny flecks of silicon mounted to metal carriers and embedded in epoxy or ceramic. The first integrated circuits, albeit a looser definition of such, were just a few transistors, resistors, and diodes mashed together in the same package. With this in mind, [Rupert] created his own custom IC. It’s an IR
receiver transmitter constructed out of a transistor, resistor, and an LED.
The attentive reader should be asking, “wait, can’t you just buy an IR
receiver transmitter?” Yes, yes you can. But that’s not a hack™, and would otherwise be very uninteresting.
[Rupert]’s IC is just three parts, a 2n2222 transistor, a 220Ω resistor and an IR LED. With a good bit of deadbug soldering, these three parts were melded into something that resembled, and had the same pinout of, a Vishay TSOP4838 IR receiver. The epoxy used to encapsulate this integrated circuit is a standard 2-part epoxy and laser printer toner. Once everything is mixed up into a gooey slurry, it’s dripped over the IC producing a blob of an integrated circuit. It’s functionally identical to the standard commercial version, and looks good enough for a really cool project [Rupert]’s been working on.
Thanks [foehammer] for the tip.