Update tutorial and fix bugs in traps

Squashed commit of the following: dede7d5...9f75939

.go-version

@@ -1 +1 @@
-1.21.3
+1.21.4

docs/DEVGUIDE.txt

@@ -51,10 +51,10 @@ ELSIE has the following dependencies:
   - optionally, golangci-lint to check Go coding style.
 
 As a learning tool, ELSIE has a design goal that its development should simple
-and easy. To that end, dependencies are restricted to only tools, packages, and
+and easy. To that end, dependencies are restricted to tools, packages, and
 methods that are supported by the Go Development Team. This includes Go and its
-standard library, of course, but also includes modules in the "golang.org/x"
-namespace, modules for dependency management, and simple text file formats.
+standard library, of course, but also modules in the "golang.org/x" namespace,
+using modules for dependency management, and simple text file formats.
 
 Each design decision that introduces a dependency adds complexity, limits
 portability, and requires another skill or trivial knowledge from future
@@ -63,9 +63,7 @@ makes things unexpectedly more difficult over longer time scales. So, we limit
 ourselves to essential tools only. Notably, this excludes some very common and
 standard tools like make, shell and YAML.
 
-Go is not perfect, nor are its developer's or corporate sponsors infallible; far
-from it in fact. However, by acknowledging its flaws and yet embracing
-minimalism and Normhaus design, we make space for essential understanding and
-creativity to form and we build things that have a better chance of standing the
-tests of time. So long as Go is maintained, we can expect some motivated people
-to be able to fix its problems.
+My acknowledging its flaws and embracing minimalism and Normhaus design, we make
+space for essential understanding and creativity to form and we build things
+that have a better chance of standing the tests of time. So long as Go is
+maintained, we can expect some motivated people to be able to fix its problems.

docs/README.txt

@@ -1,25 +1,26 @@
-                       ELSIE: A Pedagogical LC-3 Emulator
+                       𝔼𝕃𝕊𝕀𝔼: A Pedagogical LC-3 Emulator
 ================================================================================
 
             The path is made in the walking of it. -- Zhuangzi
 
-This is  ELSIE, an exploration  of the LC-3: a  little computer that  is simple,
-comprehensive, and imaginary.
+This is 𝔼𝕃𝕊𝕀𝔼, an exploration of the  LC-3: a little computer that is simple and
+imaginary.
 
 The project includes:
 
- - a virtual machine, that executes instructions;
- - an assembler, for translating from LCASM source to machine code;
- - a loader, that puts programs into memory;
- - a system monitor or BIOS, that implements system calls;
- - virtual devices for display and keyboard I/O;
+ - a virtual machine that executes instructions;
+ - an assembler for translating LCASM source to machine code;
+ - a loader that puts programs into memory;
+ - a system monitor that implements system calls;
+ - virtual devices  for display and keyboard I/O;
  - many unnecessary words by your author; and
  - maybe, more to come…
 
-As a technical  project, ELSIE is not  useful: it isn't complete  and it doesn't
-work. In  those terms, it  is not good software.  To the author,  however, ELSIE
-feels more like a story, a performance,  or maybe even a convalescence. As such,
-it is software useful for more than mere utility and is essential.
+As a technical  project, 𝔼𝕃𝕊𝕀𝔼 is not  useful: it isn't complete  and it doesn't
+work. In  those terms,  it is  not good  software. However,  to the  author, the
+project  is not  intended to  be solely  utilitarian --  it is  also a  story, a
+performance, or maybe even a trail through  a cozy wood. As such, it is software
+that is essential and invaluable.
 
 -----------------------------
          Background
@@ -41,12 +42,11 @@ The LC-3 instruction set and architecture includes:
   - an instruction set compact enough to fit on a single page.
 
 Far  from an  abstract machine,  the text  begins with  transistors and  digital
-logic. From there,  it builds upon the  titular bits and bytes  and describes in
-detail   the   entire   computer   architecture   including   the   control-unit
-state-machine,  data and  I/O paths.  It is  fascinating. As  far as  I know,  a
-complete implementation has never been physically  built but, I can imagine, the
-text  will be  invaluable when  humanity has  to recreate  computers from  first
-principles.
+logic. From there,  it builds upon the  titular bits and bytes  and describes an
+entire computer architecture in detail including the control-unit state-machine,
+data  and  I/O  paths.  It  is  fascinating.  As  far  as  I  know,  a  complete
+implementation has never been physically built but, I can imagine, the text will
+be invaluable when humanity has to recreate computers from first principles.
 
 While similar  in many respects to  the x86 or  ARM ISAs, the LC-3  is radically
 simpler  in almost  every  way.  Unlike the  sprawling  x86,  with thousands  of
@@ -62,7 +62,7 @@ enough to write programs.
        Project Goals
 -----------------------------
 
-ELSIE is not novel: hardware simulators already exist for the LC-3 architecture,
+𝔼𝕃𝕊𝕀𝔼 is not novel: hardware simulators already exist for the LC-3 architecture,
 of course. The textbook publishers provide  one and there are many others freely
 available online.[1]  This one is  admittedly a  mere reinvention of  the wheel.
 That said, the gift the design and engineering process affords is that sometimes
@@ -136,6 +136,6 @@ This work is dedicated to the MCM/70[2] and its pioneering designers.
 
 -----------------------------
 
-ELSIE © 2023 by Scott Moynes is licensed under CC BY-SA 4.0.
+𝔼𝕃𝕊𝕀𝔼 © 2023 by Scott Moynes is licensed under CC BY-SA 4.0.
 See LICENCE.txt for terms. Send your lawyers here:
 https://creativecommons.org/licenses/by-sa/4.0/?ref=chooser-v1