AT&T's Hobbit Microprocessor (2023)

However the Hobbit wasn&#x27;t a stack machine, it was a memory-to-memory machine with a stack cache.<p>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.<p>The stack cache is effectively a form of register window. The ISA could have or might have (I don&#x27;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.

The Hobbit was the original CPU for the BeBox, one of the most fabled 1990s “what could have been” hacker machines:<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;BeBox" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;BeBox</a>

My husband worked for Go Corporation and there is a small pile of EO Personal Communicator bits and pieces sitting in our garage.<p>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.

&gt;&gt; With apologies to J.R.R. Tolkien<p>Why? The word &quot;hobbit&quot; 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).<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Hobbit_(unit)" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Hobbit_(unit)</a> <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Hobbit_(word)" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Hobbit_(word)</a>

I ended up writing about the EO Personal Communicator a few years ago:<p><a href="https:&#x2F;&#x2F;www.inverse.com&#x2F;input&#x2F;features&#x2F;fax-on-the-beach-the-story-of-atts-eo-communicator-90s-ipad-flop" rel="nofollow">https:&#x2F;&#x2F;www.inverse.com&#x2F;input&#x2F;features&#x2F;fax-on-the-beach-the-...</a><p>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.

I’m always surprised that when people talk about stack computers they don’t mention the Burroughs B55&#x2F;65&#x2F;67&#x2F;7700 and A Series computers. They ran Algol (pre C) super fast.

&gt; So Larry Tesler, now in charge of the Newton project, orchestrated a switch to the ARM architecture in 1990.<p>ARM seems to have worked out pretty well.

&gt; The CRISP architecture was described as a &quot;2½ address memory-to-memory machine&quot;, where instructions can employ zero, one, or two memory addresses and can employ a stack entry called the accumulator for computation results.<p>Ewwww<p>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.

I have an EO 440 in my house. The disk is slightly corrupt and some of the apps (including the configuration app) don&#x27;t work, unfortunately.

Reminds me of Transmeta Crusoe. Innovative but insufficiently performant.<p>OTOH, LISP stack-based machines were fairly successful in their day.

The following progression is a clear downward trajectory: transitor, C&#x2F;Unix, this thing.

&gt; In addition, the Hobbit was buggy and, as the Hobbit was exclusive to Apple, AT&amp;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<p>So maybe TSMC shall learn something from history and not rely only on Apple for some processes.