@kenshirriff "[...] two is always one too many architect" 😅

@kenshirriff
Thank you, and thank you for boosting this post @philpem
I watched the whole video, this conveys engineering excellence, I do not hear engineers these days speak like this. All I hear out of current engineer's mouths is whining about when they're going to arrive at C-suite and who is going to do the work.

@kenshirriff I think I wrote an ML program com file using debug to test for that in less than 10 bytes. The windows patch couldn't stop it.

@kenshirriff 50 C001! 7H4NK U 50 MUCH!

@kenshirriff i dont understand half of it but its rlly impressive :blobcatspace:

@kenshirriff

Oh, imagine the phun to be had working that solution out from yield problems!

@kenshirriff a pure example of DFM - Design for Manufacturing

@kenshirriff Are these diodes on the pins bonded out to the package or are they internal as i.e. on internal traces?

@kenshirriff

At first glance, I thought this was the map screen from the original Pokémon.

@kenshirriff Intel Inside, can't divide!

@kenshirriff oh that looks like my cuircuit making module in factorio :grin:

@kenshirriff I hate the Internet so much for making me think that was something horrible at first glance

@kenshirriff https://faydoc.tripod.com/cpu/jnl.htm

@kenshirriff IC what they did there.

@kenshirriff think I had a couple of those in my compus, along the lines 👍🏻

@kenshirriff
Hang on a second. Out of curiosity, I went and looked up the fabrication process for that P5. Wikipedia says the original was 800nm. Current-gen dies (like the Apple M4) are 3nm. Do I have that right? Are those numbers really comparable?

@kenshirriff We are Borg.

@kenshirriff An eye-opening chart. (One note: Buffett should have two t's.)

@kenshirriff I cannot say how absurd this is. There are a bit more than 800 people who are actually represented in this diagram: The rest is “too poor” to be represented — even if they own (almost) a billion Dollars.

If you own less than a billion, we cannot care for you... — I am sure this diagram shows the world view of people like Musk or Bezos.

@kenshirriff US Oligarchy

@flexion That's close to me and I've been there a couple times! Unfortunately they started moving everything out and into a new facility in Wyoming a few years ago, and it's pretty much all empty now.

@kenshirriff crumbs @Isolectra

@kenshirriff When it doesn't work, in my plane 😜

https://youtu.be/c03inuI3_kc

@kenshirriff

f-4 was an interesting plane.

when i was in the air force, pilots used to joke that the f-4 was living proof of the rule of aerodynamics that given sufficient thrust, even a brick could fly. downside was that when the f-4 lost thrust, it reverted to brick.

but they had a long and pretty solid life span in service.

@kenshirriff This brings back memories of an IBM 360 derivative machine from the 1970s that had memory modules made of tiny magnetic core donuts with tiny wires orthogonal to each other. Maybe they were 8K each but the improved ones were 16K I think.

@kenshirriff great thread thankyou, followed

@kenshirriff

But with those capacities, we're back to having full-length RAM adapter cards in our systems, eh? I miss those days!

Here's the schematic, from the datasheet. Each stage holds the sampled voltage in a capacitor. The two clock phases push the capacitors up and down like a charge pump, dumping the charge into the next capacitor. Thus, the input signal appears at the output 256 clock cycles later.

@kenshirriff they have a distinctive sound, but you can't stomp on them like you can with a spring reverb

Am I understanding it correctly that it takes analog signals as input, digitizes them, processes them, and then outputs them as analog again? Strange indeed. I've always thought of DSPs as specialized chips that process an already digital signal that may come from an ADC but also from memory for example.

@kenshirriff reminds me of a MAXQ DSP I read about described as "opcode-less"

Every part of the chip would do something every clock cycle, so the "instructions" were nothing but a set of operands for all the units

Seems like quite a rare design now -- probably because scheduling, pipelining, and speculative execution have beaten it in total throughput

Amazing how silicon design has changed

@kenshirriff I remember these! When I was getting my EE degree at Arizona State University back in the mid-80s we had a few development systems for these chips in the lab and I remember reading up on them at the time. They were already obsolete and unused AFAIK but it definitely piqued my curiosity. Sad that they didn't fix the bugs and expand on the concept as it definitely would have been useful. Microchip's dsPIC products came along years later and were very successful in the same space.

@kenshirriff Looks a little like launching a Steam game under Wayland and Plasma, which I tried during the weekend

@kenshirriff
Hello, Ken. This is beautiful. Thank you for sharing. It reminds me of an article I wrote recently, interweaving modern and indigenous knowledge about objects and their intelligence. In it I wanted to explain, among other things, that the indigenous shaman is closer to computer engineering than a religious priest.
https://codigosferales.wordpress.com/2024/07/28/exploratory-notes-on-artificial-intelligence-and-indigenous-thought/

@kenshirriff Wow, super cool. National Gallery of Art is a great museum as well.

The display is constructed as a matrix. One line selects the digits and one line selects the value of that digit. On the back, each digit has a diode matrix card.

@kenshirriff smooth

@kenshirriff Is this how odometers on older cars work?

The chip I photographed is the i486 SX, which is the version of the 486 without a floating point unit. But you can see from the photo that it has a floating point unit on the die. It's unclear if Intel deliberately disabled the floating point unit to segment the market between the low-end SX and the high-end DX, or if chips with an FPU fault were sold as the SX.

@kenshirriff damn this made me find out that CPU cores are a lot smaller than I thought and occupy less than half of the entire thing, both in modern CPUs and I assume in this one if the decode logic part is what would be described as a CPU core (I don't know that much about computer science)

@kenshirriff Are more details coming? The part labeled FPU is surprisingly small compared to the parts labeled data path (control). How much was microcoded?

@kenshirriff I know this sounds like a dumb question but how did they test that their ICBMs could hit their targets.

You can't just fire a dummy ICBM at Russia for obvious reasons.

@kenshirriff
Seid froh, dass ihr das nicht einsetzen musstet, das Ding wäre niemals geflogen, die Kabel sind viel zu eng und nicht keramisch isoliert, es wäre nie durch eine ionisierende Wolke gekommen.

@kenshirriff As always, your post is highly interesting. In particular those about embedded systems like this one broaden my understanding of what a computer is, was, and could be. Thanks a lot!

The original Pentium was power-hungry, so Intel soon released an updated version that could turn off the clock to parts that weren't being used, saving power. The original (P5 architecture, part number 80501) on the left has a noticeably larger die and package than the update (P54C, 80502). The original was built with Intel'ss 800 nm BiCMOS process, while the update was 600 nm.

@kenshirriff You don't fancy hunting an FDIV bug?

@kenshirriff I have a lot of affection for the Pentium. The first 64-bit (-data-bus) x86 CPU. 😌

@kenshirriff did that 59 pounds include paper or was that additional?

@kenshirriff

It looks like the rhino model from warhammer 40k!

@kenshirriff It cost $1.4 million just to load the ink cartridge and paper and $100,000 to launch it.

@kenshirriff
And there you have the direct ancestor of the anti-vax movement. In fact all the anti-science movements. Our generation thought it was funny the next generation took it as a gospel from the mount.

@kenshirriff I have some of his stand-up on CD. Lincoln's press agent opens with "Hey, Abe baby! How ya doin?"

He used to do a two-hand act, but the other guy wasn't ready to go pro, so Newhart rewrote their routines into one-sided telephone calls.

I highly recommend stand-up by Andy Griffith ("Romeo and Juliet"), and the classic Nichols and May (they invented improv comedy). Nichols directed "The Graduate", Elaine May did "Birdcage". Ferocious talents, and mostly forgotten.

@kenshirriff thanks Ken, that reminded me of the 1970s and when I used to feed them in, and stand there worrying was this the future of computing!

Mainframes were extremely slow compared to modern computers but they could support rooms full of users. The trick was that mainframes offloaded the text editing to the terminals, while a special "I/O channel processor" pumped data directly into memory without using the CPU. 2/14

@kenshirriff One question that may sound really stupid but "I really cannot understand", you reverse engineer those IBM chips ... But .. does it mean IBM has lost all the lore about them or they don't want to make it publicly available ? Why ? And if that's the case "why they don't come after you for exposing it ?". I mean it's all super cool, super clever, "tremendous exercise" but does it mean "original documentation is lost forever" ?? 🤔

@kenshirriff Oh yes those early chips were so easy to copy. I once watched someone do that job.