[HN Gopher] Decap of a tiny chip that plays Christmas songs
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Decap of a tiny chip that plays Christmas songs
Author : Eduard
Score : 116 points
Date : 2021-12-19 10:15 UTC (12 hours ago)
(HTM) web link (twitter.com)
(TXT) w3m dump (twitter.com)
| siraben wrote:
| What resources are there for learning about how to read die
| shots? I'm surprised that one is able to glean so much
| information from it.
| kens wrote:
| I focus on 1970s and 1980s chips, which are simple enough to
| understand. For that generation, Mead and Conway's Introduction
| to VLSI Systems is a good place to start.
| https://ai.eecs.umich.edu/people/conway/VLSI/VLSIText/PP-V2/...
| Old books on chip design are also useful, and can usually be
| obtained for cheap. Also see The Layman's Guide to IC Reverse
| Engineering: http://siliconzoo.org/tutorial.html
| baybal2 wrote:
| I'm afraid, none.
|
| It takes one to make chip, to read one later
| xattt wrote:
| What are some top schools for getting into chip
| manufacturing? Is this the right way at looking about getting
| into the field?
| baybal2 wrote:
| I'm afraid none in the West. Speaking, and writing
| Taiwanese Chinese is something really needed to get onto
| the cutting edge of device fabrication.
|
| An average US college will tell you about VLSI, logic,
| teach you Cadence, and designing something on the level of
| 8051, and process engineering enough to work on something
| from 350-180nm era with aluminium interconnect.
|
| The problem is this is hardly enough to make you
| employable. And without employment in few serious semi
| companies left standing today, you will never see modern
| chip manufacturing.
|
| Semi industry has really high entry barriers, and it has
| really poor remuneration. The industry largely coasting on
| greying cadres from eighties-nineties in the West, and very
| cheap PhDs in Asia.
| hulitu wrote:
| > I'm afraid none in the West. Speaking, and writing
| Taiwanese Chinese is something really needed to get onto
| the cutting edge of device fabrication.
|
| You should take a look at http://opencircuitdesign.com/
| You don't need "to get onto the cutting edge of device
| fabrication". You need to search for a VLSI design class.
| baybal2 wrote:
| A VLSI class, even from an average university will
| contribute very little to your employability. As I said,
| Big Semi barely if ever employs entry level
| professionals. And besides Big Semi, there is really very
| few companies left.
|
| Even startups <$1m are full of seasoned professionals
| coming from abroad, seeking PhDs in US universities. I
| think it's more characteristic for semiconductor startups
| to hire much more senior engineers than the industry
| average to convince their investors, not the other way
| around.
| kken wrote:
| Nah, sorry that is just not true.
|
| Try this one for the US:
| https://sunypoly.edu/research/albany-nanotech-
| complex.html
|
| Or this one for Europe: https://www.imec-int.com/en
|
| Both world-leading semiconductor technology research
| institutes (coincidentally both got the first EUV-tools)
| with plenty of students.
| baybal2 wrote:
| I know IMEC as I was thinking going there at some point.
|
| Both IMEC, and SUNY are heavily graduate research
| oriented. There are some undergrad opportunities there,
| but one's chances to get there are probably less than
| getting into MIT.
|
| The "death valley" in between graduation, first
| employment, and a first real substantial job in semi
| industry is super-duper real, and acute problem. It's a
| problem in Asia, and 10x of than in US.
| trevyn wrote:
| I mean, what do you mean by "chip manufacturing"? I'm
| sure there are plenty of people _designing_ chips at
| Intel /AMD/Nvidia/Apple/etc. that are good at reading die
| shots, so the real question might be, what career path
| will get you to work closely with these people and learn
| from them.
|
| Unless you actually mean working at a fab? Which strikes
| me as more process engineering than typical HN interests.
| baybal2 wrote:
| An average semi engineering course in US/Canada will
| teach you a bit of everything, including physical device
| manufacturing.
|
| India is much more VLSI, and applied skills heavy
| (Cadence,) thus they dominate there.
|
| None of US multinationals will hire a fresh "average" US
| semi engineering graduate. Maybe MIT + 1 more top
| schools, but otherwise fresh grads have no chances on the
| job market against already experienced people coming from
| Asia to do their PhDs in US.
| trevyn wrote:
| Right! My point is that they _will_ hire fresh software
| engineers /other disciplines, and then with some
| networking and being on an adjacent team, you get access
| to informal learning opportunities and internal transfer
| opportunities, so that over the longer arc of your career
| you can get into whatever field you want.
| [deleted]
| tyingq wrote:
| The author of the tweet (Ken Shirriff) is particularly good at
| explaining things. A couple of his posts showing that:
|
| http://www.righto.com/2018/06/silicon-die-analysis-op-amp-wi...
|
| http://www.righto.com/2016/02/555-timer-teardown-inside-worl...
| foobarian wrote:
| > I dissolved the transistor-like package in boiling sulfuric
| acid
|
| Well, well. Here's something cool to add to my list of home lab
| tools!
| jpm48 wrote:
| Years ago we took one of the happy birthday tune cards and
| connected it to the floppy drive hinge on a PC, the developer was
| convinced we had installed a TSR program to play it every time he
| inserted a floppy, not realising it was a hardware hack. Weeks of
| fun until he found out.
| Eduard wrote:
| As an 80s kid, these melody cards were among the first things
| that piqued my interest for what later lead me to studying
| electrical engineering / computer architecture and now doing web
| development.
|
| Funny how small experiences can shape a primary school kid's
| path. Similar experiences include those mini play-with-your-
| pinkie pianos, putting a 9V battery on the tongue, and the
| effects of putting a paperclip into an AC power socket.
| vidarh wrote:
| > putting a 9V battery on the tongue, and the effects of
| putting a paperclip into an AC power socket.
|
| Removing insulation from a live phone wire with my teeth (I had
| decided to put an extension in my room without asking for
| help...) was one of mine, that definitely made me more careful.
| Went just fine until I closed the circuit with my tongue by
| accident just as someone called. Not pleasant.
| stavros wrote:
| > Removing insulation from a live phone wire with my teeth (I
| had decided to put an extension in my room without asking for
| help...) was one of mine, that definitely made me more
| careful. Went just fine until I closed the circuit with my
| tongue by accident
|
| I read this and thought "so what?".
|
| > just as someone called.
|
| Ahh there it is. Yep, that is indeed not pleasant.
| vidarh wrote:
| Yeah, I'd done it once or twice before, and it went well
| since nobody called, and so I did not for a moment think
| about the difference. It helped strongly reinforce to make
| sure stuff is disconnected, not just "not harmful right
| this instance", before touching it.
| stavros wrote:
| I had basically the same experience. I had messed with
| phone wires a lot, and they were always harmless, until
| someone called one day. I messed with them more carefully
| from then on :P
| 13of40 wrote:
| The 90v(?) AC that comes through the phone line to make
| it ring was intended to be powerful enough to ring a
| physical bell. Back before the exchange was automated,
| home telephones had a hand-cranked generator to produce
| that signal. According to my dad, kids used to take those
| out of old phones and use them for all kinds of
| shenanigans. (Like shocking their friends, siblings, and
| the dog, I'm guessing.)
| gww wrote:
| I am so glad I am not the only one who did this. I was
| messing around with the phone wires because my sister was
| hogging the phone and I had important business on a MUD. I
| found if I put a large resistor across two of the wires (I
| can't remember which now) the call quality would degrade
| enough that she would stop and I could get back on the
| internet.
| jaclaz wrote:
| >and the effects of putting a paperclip into an AC power
| socket.
|
| I believe that (in earlier years when electric protections were
| non existant or just a huge fuse) is one of the origins of
| survivorship bias ...
| dylan604 wrote:
| I remember the first attic of a house of a certain age to
| learn that it used to be a thing to not have insulated
| wiring. Instead, the wiring used a series of insulators as
| standoffs/guides, but bare exposed copper carrying live
| current. I was flabbergasted that more homes didn't burn to
| the ground.
| jaclaz wrote:
| Yep, and at least here (Italy) up the '60's or maybe even
| '70's many older houses were "retrofitted" with what was
| called "piattina", which you can see here attached to a
| switch and to a socket:
|
| http://www.museolaluce.com/wp-
| content/uploads/2009/03/vimar4...
|
| it was two wires (no earth/ground) and was fixed using tiny
| nails that were driven in the plastic slip between the two
| wires, the "luxury" version were these (on the right):
|
| http://www.museolaluce.com/wp-
| content/uploads/2009/03/btic.j...
|
| but the most common ones had not a real insulator, they
| were simply steel nails dipped in some rubbery paint.
|
| In theory the nail should have never come in contact with
| any of the two wires, but expecially where there was some
| corner preventing the nail to be hammered perfectly
| straight or because of sloppy installation, after a few
| years (with the rubber/insulation becoming stiff and
| microcracking) it happened.
| drfuchs wrote:
| Look up "Knob And Tube Wiring" on Wikipedia for details
| (which claim that the wires should have been insulated, but
| I believe I've seen the same as you report, in a California
| house built in the 1950s).
| robin_reala wrote:
| Without wanting to be _that_ guy, I'm really glad I grew up in
| a country with shuttered power sockets.
| dbcurtis wrote:
| Interesting. There is a chip that was once one of my friend's
| favorites for his consulting work... it was essentially a 6502
| with huge mask-programmable ROM and a tiny (like 128 byte) RAM --
| it was designed for greeting cards, where if you bought 100K+
| quantities of passivated, unencapsulated die, they cost between 1
| and 2 cents.
| Maursault wrote:
| I was expecting Doom. :/
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(page generated 2021-12-19 23:02 UTC)