From cbb9044442f907bd1209736c0fcdd6aa9fa8f1ec Mon Sep 17 00:00:00 2001
From: Perry Kivolowitz <perry@kivolowitz.com>
Date: Thu, 19 May 2022 10:46:39 -0500
Subject: [PATCH] added exercises and more detailed answers

---
 section_1/hello_world/README.md |  9 ++++++---
 section_1/if/README.md          | 21 +++++++++++++++++----
 2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/section_1/hello_world/README.md b/section_1/hello_world/README.md
index 939d44d..d5a8057 100644
--- a/section_1/hello_world/README.md
+++ b/section_1/hello_world/README.md
@@ -496,7 +496,8 @@ We do maintain that understanding assembly language principles will improve your
 
 (T | F) It is the compiler's job to reduce a higher level language to assembly language.
 
-Answer: True
+Answer: True - The "compiler" is just one step in the "compilation" process. In fact it
+is step 2. Invoking the "preprocessor" is step 1.
 
 ### 2
 
@@ -508,7 +509,8 @@ Answer: False - a linker error will happen, not a syntax error.
 
 \___ and ___ implement the braces in C and C++.
 
-Answer: labels and branches.
+Answer: labels and branches - the closing brace of a `while` loop for example,
+is a branch instruction.
 
 ### 4
 
@@ -519,7 +521,8 @@ if a_register has value 0
     then goto label
 ```
 
-Answer: True
+Answer: True - `cbz` stands for "compare and branch if zero". There is also
+a `cbnz` instruction. To test for other Boolean conditions, use `cmp`.
 
 ### 5
 
diff --git a/section_1/if/README.md b/section_1/if/README.md
index 1a30d52..482a25c 100644
--- a/section_1/if/README.md
+++ b/section_1/if/README.md
@@ -1,4 +1,4 @@
-# The `if` statement
+# Section 1 / Chapter 2 / The `if` Statement
 
 We will begin with the `if` statement followed by a discussion of the `if / else`.
 
@@ -175,9 +175,11 @@ T:  .asciz  "TRUE"                                                      // 24
 In this case, the label `T` corresponds to the address to the first
 letter of the C string "TRUE".
 
-The occurrences of `.asciz` are invocations of an *assembler directive*
-the creates a C string. Recall that C strings are NULL terminated. The
-NULL termination is indicated by the `z` which ends `.asciz`.
+The occurrences of `.asciz` on `line 23` and `line 24` are invocations of
+an *assembler directive* the creates a C string. Recall that C strings are NULL
+terminated. The NULL termination is indicated by the `z` which ends `.asciz`.
+There is a similar directive `.ascii` that *does not NULL terminate* the 
+string.
 
 ## Summary
 
@@ -197,8 +199,19 @@ allow a branch to that code block, such as the beginning of an `else`.
 
 ### 1
 
+(T | F) If statements in assembly language always test for the opposite condition
+as the equivalent `if` statement in a high level language.
+
+Answer: False - it is a matter of style but you may be able to
+save an instruction or two by doing so. 
+
 ### 2
 
+(T | F) `cmp` isn't a "real" instruction but rather is an alias for a subtraction.
+
+Answer: True - `cmp` is an alias for `subs` which is a subtract that discards the
+resulting value but does set the condition bits.
+
 ### 3
 
 ### 4