[HN Gopher] AT&T's Hobbit Microprocessor (2023)
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AT&T's Hobbit Microprocessor (2023)
Author : klelatti
Score : 88 points
Date : 2024-09-15 08:04 UTC (14 hours ago)
(HTM) web link (thechipletter.substack.com)
(TXT) w3m dump (thechipletter.substack.com)
| compressedgas wrote:
| However the Hobbit wasn't a stack machine, it was a memory-to-
| memory machine with a stack cache.
|
| The LLVM uses a register machine with an unlimited number of once
| use registers. The Hobbit could easily run LLVM programs with no
| change to the number of registers used. Compiling as to reuse
| registers would only decrease the amount of stack memory traffic.
|
| The stack cache is effectively a form of register window. The ISA
| could have or might have (I don't recall) short form instructions
| that take shorter offsets from the top of the stack which would
| be similar in performance to register-to-register operations.
| pclmulqdq wrote:
| Most compilers either use an "infinite registers" abstraction
| or a "no registers" abstraction in the layer that LLVM
| occupies. It is easy enough to translate from there to
| "16/32/64 registers."
| hulitu wrote:
| > In addition, the Hobbit was buggy and, as the Hobbit was
| exclusive to Apple, AT&T wanted millions more dollars from Apple
| to continue development for the Newton. So Apple looked at the
| ARM architecture instead. Benchmarks showed the ARM design
| outperforming the Hobbit
|
| So maybe TSMC shall learn something from history and not rely
| only on Apple for some processes.
| Taniwha wrote:
| I'm pretty sure that Apple's internal silicon group rolled
| their own version, as I recall it came back after they decided
| to switch to ARM and worked perfectly.
|
| Like a lot of Apple projects of the era someone put their heart
| and soul and a year or more of their life into a project and it
| got arbitrarily canned - we hired him ....
| twoodfin wrote:
| Apple did so many of these reinvent-the-world projects in the
| systems area alone that somewhere on Earth-87 they're running
| their Hobbit-based phones on NuKernel and the apps are all
| written in Dylan.
| lostemptations5 wrote:
| I don't believe there was an Apple "silicone" group at that
| time. Thats a recent invention.
| fredoralive wrote:
| Apple definitely dabbled in silicon around that time, the
| headliner was the Aquarius RISC CPU project. They famously
| bought a Cray for it.
| kalleboo wrote:
| Before they decided on PowerPC, they had a failed attempt
| at building their own RISC CPU:
|
| https://thechipletter.substack.com/p/the-first-apple-
| silicon...
|
| https://archive.org/details/scorpius_architecture
| Taniwha wrote:
| not "silicone" that's something else.
|
| They were rolling their own north-bridge-ish chips at the
| same time for 2FX and later machines (all pre the power PC
| switch)
| the-rc wrote:
| The first true ARM MMU design was Bob Welland's, who had
| joined Apple after his stint at Commodore (C900, Amiga
| 500). It doesn't look like traditional MMUs, because it
| needed to support the Newton OS and shared address spaces.
| rvense wrote:
| They were really really bad at actually shipping products for
| a long time. I love all that ATG stuff: SK8, Dylan, all that
| blue-eyed object oriented optimism. But hundreds of man-years
| were put into all of that and Copland and Taligent, and they
| had nothing to show for it. Apple was so dysfunctional under
| Sculley and Spindler. People say Apple killed Hypercard but
| really what happened is people worked on it for years but it
| got bogged down in feature creep and focus switches, and they
| never get a functional version 3 out the door.
| samatman wrote:
| It is impossible to know what you mean by this sentence.
|
| Surely it's Apple who rely upon TSMC for 'some processes'?
| hi-v-rocknroll wrote:
| Reminds me of Transmeta Crusoe. Innovative but insufficiently
| performant.
|
| OTOH, LISP stack-based machines were fairly successful in their
| day.
| musicale wrote:
| > Reminds me of Transmeta Crusoe. Innovative but insufficiently
| performant.
|
| According to this article (circa 2003?), Crusoe was slower but
| more power efficient than Pentium-M. It suffered from a
| recession in Japan (affecting Crusoe-based laptops), poor
| execution and faulty chips leading to product delays, and being
| "outfoxed" by intel:
|
| https://www.cnet.com/tech/tech-industry/transmeta-are-the-ch...
|
| An interesting bit is how intel was apparently ahead of TSMC at
| that time.
| pavlov wrote:
| The Hobbit was the original CPU for the BeBox, one of the most
| fabled 1990s "what could have been" hacker machines:
|
| https://en.wikipedia.org/wiki/BeBox
| gorbypark wrote:
| I dream of owning one of those one day! I was a huge BeOS fan
| as a teenager, and even though the BeBox was from before my
| time I'd love to own one! They very very rarely seem to come up
| for sale, though. And the ones that do are pretty crazily
| priced..
| sillywalk wrote:
| IIRC there were only ~1000 66MHz and ~800 133Mhz BeBoxes
| produced.
|
| In comparison, I'd be curious as to how many, say, SGI O2s
| were ever produced in total.
| AstroJetson wrote:
| I'm always surprised that when people talk about stack computers
| they don't mention the Burroughs B55/65/67/7700 and A Series
| computers. They ran Algol (pre C) super fast.
| Taniwha wrote:
| fastish - our B6700 had roughly microsecond core and as a
| result was ~1MIP
| formerly_proven wrote:
| > The CRISP architecture was described as a "21/2 address memory-
| to-memory machine", where instructions can employ zero, one, or
| two memory addresses and can employ a stack entry called the
| accumulator for computation results.
|
| Ewwww
|
| This sounds like something from the 70s and not like a new
| architecture for a mid-1990s microprocessor - and indeed the 70s
| seems to be where the design actually came from.
| dfox wrote:
| The instruction encoding has strong S/360 feeling to it. Which
| is not necessarily a bad thing in itself.
| sandworm101 wrote:
| >> With apologies to J.R.R. Tolkien
|
| Why? The word "hobbit" predates Tolkien and was used in a variety
| of ways. It might seem pedantic, but while the use of old words
| is one thing, there is a trend as of late whereby authors who
| popularize old words then claim ownership. Tolkien is beyond this
| but others such as the Potter franchise are not (Padfoot).
|
| https://en.wikipedia.org/wiki/Hobbit_(unit)
| https://en.wikipedia.org/wiki/Hobbit_(word)
| klelatti wrote:
| The apology is for the parody of Tolkien not for the use of the
| word Hobbit.
| Svoka wrote:
| Because the "Hobbitses" intro is a rephrasing of
| Gollum/Smeagol.
| samatman wrote:
| Oddly, the Wikipedia page doesn't include the most likely
| inspiration, the Hobyahs:
| https://en.wikipedia.org/wiki/The_Hobyahs
|
| The parallels are pretty unmistakable. I believe the good
| Professor when he says he could recall no prior inspiration for
| the word, but: Bag-End. That's the Hobyah's whole thing, the
| bag. That and turnips.
| shortformblog wrote:
| I ended up writing about the EO Personal Communicator a few years
| ago:
|
| https://www.inverse.com/input/features/fax-on-the-beach-the-...
|
| Was never able to get the device working (I have two) but I still
| have them in my possession. So I have some of the few Hobbit
| microprocessors in the wild.
| julesallen wrote:
| I had one of these and I think I bought it from Staples, Office
| Depot, or whatever the predecessor to this was. I can't
| remember the exact timing but I picked up an IBM Simon around
| the same time.
|
| Both were half baked products that ended up in a drawer after a
| couple of weeks. The EO had lousy battery life and not as good
| as pen and paper for note taking which is why I wanted it.
|
| I had various devices over that time frame which included the
| Palm Pilot, Sony Magic Link, all of the Newtons, a Sharp
| Zaurus, and so on. The one that really stuck was the Psion MX5
| as I could actually touch type on it.
| shortformblog wrote:
| The person who sent along the EOs also sent a Simon. I
| couldn't get that working either. Sigh.
| julesallen wrote:
| If it's any consolation you're really not missing much!
| LeoPanthera wrote:
| My husband worked for Go Corporation and there is a small pile of
| EO Personal Communicator bits and pieces sitting in our garage.
|
| I was always on Team Psion, and I still miss the foldable-with-
| keyboard form factor today. It seems perfect, but despite one
| failed attempt from Planet Computers, no longer exists in any
| useful product.
| musicale wrote:
| > So Larry Tesler, now in charge of the Newton project,
| orchestrated a switch to the ARM architecture in 1990.
|
| ARM seems to have worked out pretty well.
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