Compare Vectors   - COMPB, COMPBC
Compare Filenames - @FNCMP, @AFNCMP
Compare HL to DE  - COMPHD
Substring Search  - INSTR
Vector Search     - SCANNER
-------------------------------------------------------------
COMPB  - Compare Vectors of 1 to 256 bytes in length
COMPBC - Compare Vectors of 1 to 65536 bytes in length

  ENTER: HL, DE - Pointers to Vectors to compare
	 BC (for COMPBC), B (for COMPB) = # of bytes to Compare
  EXIT :  F - Zero and Carry Set/Reset as:
		Zero Flag Set (Z)		 ==> HL = DE
		Carry Flag Set (C)		 ==> HL < DE
		Zero and Carry Reset (NZ and NC) ==> HL > DE
  USES : AF

 Usage:  These routines are most commonly used to do String
  Comparison.  Since all eight bits are used in the compare
  logic, they are also suitable for raw binary elements as
  well.  COMPB uses only an 8-bit counter (B Register) and can
  compare one to 256 bytes, while COMPBC uses a 16-bit counter
  (BC pair) and can compare one to 65,536 bytes.  The maximum
  counts of 256 and 65536 are achieved by setting the counter
  register(s) to Zero.

@FNCMP - Perform Unambiguous 7-bit Comparison

  ENTER: HL = Pointer to first string to match
         DE = Pointer to second string to match
          B = Number of chars to check (0 checks 256)
  EXIT :  F - Zero Flag Set (Z) if Strings Match
		Zero Flag Reset (NZ) if No Match
              Carry flag set (C) if (DE) is less than (HL)
  USES : AF,BC,DE,HL

 Usage:  This routine is most often used in comparing file
  names and types.  It performs 7-bit comparisons, ignoring any
  attribute bits (bit 7).  In general use, it compares two
  strings of one to 256 characters in length.  In addition to
  equality, the inequalities of Greater Than and Less Than are
  also supported by also sensing the Carry flag.

@AFNCMP - Perform Ambiguous 7-bit Comparison

  ENTER: HL = Pointer to possibly Ambiguous String
         DE = Pointer to second string to match
          B = Number of chars to check (0 checks 256)
  EXIT :  F - Zero Flag Set (Z) if Match Ok
		Zero Flag Reset (NZ) if No Match
  USES : AF,BC,DE,HL

 Usage:  This routine is most often used to compare Filenames
  and types, where one name may be ambiguous (question marks,
  "?", match any character).  Most Significant Bits (Bit 7) of
  both strings are masked with only the least significant bits
  being compared.  It may also be used as a general 7-bit
  utility compare strings of one to 256 characters in length.

 Examples:

	EXT	@AFNCMP,@FNCMP	; Declare the routines
	...			; ..preceeding code
	LD	HL,AMBIG	; Set ptr to ambiguous name
	LD	DE,FNAME	; Set to name to check
	LD	B,11		; Match filename and type only
	CALL	@AFNCMP		; ..call the routine
	JR	Z,OK		; Jump if match
	...			; Else here if mismatch
	...
	LD	HL,ENTRY1	; Set ptr to first name
	LD	DE,ENTRY2	; ..and name to check
	LD	B,11		; Match filename and type only
	CALL	@FNCMP		; ..call the routine
	JR	Z,EQUAL		; Jump if same
	JR	C,ONEMORE	; ..jump here if ENTRY1>ENTRY2
	...			; Else here if ENTRY1 < ENTRY2

COMPHD - 16-bit Value Comparision

  ENTER: HL, DE = Values to Compare
  EXIT :  F = Status set by Zero and Carry Flags as:
		Zero Flag Set (Z)		 ==> HL = DE
		Carry Flag Set (C)		 ==> HL < DE
		Carry and Zero Reset (NZ and NC) ==> HL > DE
  USES : AF

 Usage:  This routine is commonly used to compare two 16-bit
  values such as addresses or integer values.

INSTR - Substring Search (Null-terminated Char Strings)

  ENTER: HL = Pointer to Null-terminated String to be Scanned
	 DE = Pointer to Null-terminated Substring to locate
  EXIT : HL = Ptr to beginning of Substring in String if Found
		(unaffected if Not Found)
	  A = 0, Zero Flag Set (Z) if Found
	      A <> 0, Zero Flag Clear if NOT found
  USES : AF,HL
  Special Error Condition: Automatic success if Substring is
	of Zero-length (Null String)

 Usage:  This routine is most often used to locate a character
  string within a larger body of text, such as within a simple
  text editor.

SCANNER - Vector Search

  ENTER: HL = Pointer to Vector to be Scanned
	 DE = Pointer to Vector to locate
	 BC = Vector lengths as:
		B = Number of bytes in HL-vector
		C = Number of bytes in DE-vector
  EXIT : HL = Pointer to located Vector (unchanged if Not Found)
	  F = Zero Flag Set (Z) if Found (A indeterminate)
		A <> 0, Zero Flag Reset (NZ) if NOT Found
  USES : AF,HL
  Special Error Condition:  Automatic failure if Scanned Vector
		is shorter than Vector to locate (B < C)

 Usage:  This routine is used to locate a string of bytes in a
  block of up to 255 bytes.  Since only 8-bits are available
  for length values for both the Search and Target Vectors,
  neither length can exceed 256.  Because of the logic used,
  the block to be scanned must be of Non-zero length to avoid
  an error for search lengths less than 256 (0 length byte).