small documentation refinements

doc/asm6502.but

@@ -88,7 +88,7 @@ Beside generating an output file containing machine code, ASM6502 may also gener
 
 Pos indicates the position of the instructions regarding the output file. Addr represents the \e{location} or \e{address} of the code while it is executed.
 
-Let's further elaborate what the arguments to instructions may be. In the example above, \c{#42} is a numeric value that is directly used to do the addition. It is therefore called an \e{immediate} value, and the mode the processor operates in is called \e{immediate addressing} mode. The \c{INX} instruction above implicitly operates on a register called X. For this reason it is called \e{implicit addressing}. Often, the argument specifies a memory location. This memory location may be referenced to the start of the address space. In this case it is called \e{absolute addressing} mode. If the memory location is specified relative to some other location we call it \e{relative addressing} mode. Sometimes one does not want to encode a fixed memory location into the machine instruction, but instead use the content of some memory location as the address to operate on. This is called \e{indirect addressing}.
+Let's further elaborate what the arguments to instructions may be. In the example above, \c{#42} is a numeric value that is directly used to do the addition. It is therefore called an \e{immediate} value, and the mode the processor operates in is called \e{immediate addressing} mode. The \c{INX} instruction above implicitly operates on a register called X. For this reason it is called \e{implicit addressing}. Often, the argument specifies a memory location. This memory location may be given relative to the start of the address space. This it is called \e{absolute addressing}. If the memory location is specified relative to some other location, we call it \e{relative addressing}. Sometimes one does not want to encode a fixed memory location into the machine instruction, but instead use the content of some memory location as the address to operate on. This is called \e{indirect addressing}.
 
 The sequence of instructions executed by the processor may be altered by the programmer utilizing special machine instructions. Some of these instructions modify this sequence unconditionally, and some alter it if a special condition is met. The instructions are called \e{jump} or \e{branching} instructions. The information of the \e{jump target} is encoded as address within the instruction. The assembler supports the programmer by letting him specify a jump target by giving it a name, called \e{label}. In the introductory example, \c{basic_upstart}, \c{start}, and \c{hello} are labels.
 
@@ -219,7 +219,7 @@ Examples:
 
 \c 2+3*5        ; value 17
 \c $4700 | $11  ; is $4711
-\c 255+255      ; of type word because >256
+\c 255+255      ; of type word because >255
 
 
 \S{}Byte-select and Conversion Operators
@@ -457,14 +457,14 @@ A byte-sized address is encoded following the opcode byte. The assembler interpr
 
 \S{}Absolute X and Absolute X Addressing
 
-The address is encoded in the word following the opcode and displaced by the contents for the X or Y register.
+The address is encoded in the word following the opcode and displaced by the contents of the X or Y register.
 
 \c LDA $4711,X ; load contents of address $4711 displaced by X
 \c LDA $4711,Y ; load contents of address $4711 displaced by Y
 
 \S{}Zero-page X and Zero-page Y Addressing
 
-The address is encoded in the byte following the opcode displaced by the contents for the X or Y register.
+The address is encoded in the byte following the opcode displaced by the contents of the X or Y register.
 
 \c LDA $47,X ; A = contents of address $47 displaced by X
 \c LDX $11,Y ; X = load contents of address $47 displaced by Y
@@ -483,7 +483,7 @@ To correct this, you may rewrite it as:
 
 \c JMP +(2+3)*1000
 
-This one is correct (indirect addressing):
+or
 
 \c JMP ((2+3)*1000)