minor documentation corrections/clarifications

docs/Game Completion Modifier.md

@@ -2,7 +2,7 @@
 
 _Contra_ is already a challenging game.  However, it gets even more difficult
 the more times you beat the game.  This documents the ways in which beating the
-game affects the behavior of subsequent playthoughs.
+game affects the behavior of subsequent playthroughs.
 
 The game keeps track of the number of times the player(s) beat the game in the
 variable `GAME_COMPLETION_COUNT`, located at CPU memory address `$31`.

docs/Graphics Documentation.md

@@ -347,8 +347,8 @@ article on this.  These specifics are also outlined below.
 
 When the first byte of the sprite code is #$fe, the sprite is a "small" sprite.
 Small sprites are composed of #$3 bytes, including the #$fe byte.  Small sprites
-always have their X position set to #$fc (-4) and their Y position set to #$f8
-(-8).
+always have their X position shifted left by #$04 and their Y position shifted
+up byte #$08.
 
   * Byte 0 is #$fe and signifies the sprite is a small sprite
   * Byte 1 specifies the tile number

src/bank1.asm

@@ -4179,7 +4179,7 @@ load_sprite_to_cpu_mem:
 ; the second byte is the pattern table tile, and the third byte is the sprite attributes
 ; the X position is set to #$fc (-4 decimal) and the Y position is set to #$f8 (-8 decimal) from SPRITE_Y_POS.
 @load_small_sprite:
-    ldx $04                   ; load sprite y position
+    ldx $04                   ; load OAM write offset
     lda #$f8                  ; a = -#$08
     clc                       ; clear carry in preparation for addition
     adc $01                   ; subtract #$08 from y position

src/ram.asm

@@ -268,7 +268,7 @@ CURRENT_LEVEL:
 GAME_COMPLETION_COUNT:
     .res 1
 
-; $32 -P1 number of lives, #$00 is last life, on game over stays #$00
+; $32 - P1 number of lives, #$00 is last life, on game over stays #$00
 ; but P1_GAME_OVER_STATUS becomes #$01
 P1_NUM_LIVES:
     .res 1