 GP Numeric String Evaluation   - EVAL
 Hexadecimal String Evaluation  - EVAL16
 Decimal String Evaluation      - EVAL10
 Octal String Evaluation        - EVAL8
 Binary String Evaluation       - EVAL2
:EVAL - General-Purpose Numeric String Evaluation

  ENTER: HL = Address of first byte of string to convert
  EXIT : HL = Points to character after converted string
                (or char causing error if error flag set)
         DE = 16-bit Binary value of string
          A = E value, Carry Flag Clear (NC) if Ok
                Carry Flag Set (C) if Error in String
  USES : AF,DE,HL

 Usage:  This routine converts the character string pointed to 
by HL into a 16-bit binary representation.  EVAL performs the
conversion until a non-hexadecimal character is encountered, at
which time it looks at the last character and the previous
character to determine if the string is representing a binary,
octal, decimal, or hexadecimal number.  Input string characters
may be upper- or lower-case.  Valid input string formats are --

	bbbbbbbbbbbbbbbbB -- b=0 or b=1; Binary string	
	ttttt or tttttD -- 0 <= t <= 9; Decimal string
	hhhhH or hhhhX -- 0 <= h <= F; Hexadecimal string
	oooooooO or oooooooQ -- 0 <= o <= 7; Octal string
:EVAL16 - Hexadecimal String Evaluation

  ENTER: HL = Address of first char of string to convert
  EXIT : HL = Points to Character terminating conversion
         DE = Contains the 16-bit binary value of string
          A = E value
  USES : AF,DE,HL

 Usage:  EVAL16 converts the string of ASCII hexadecimal 
characters pointed to by HL into a 16-bit binary value.  
Conversion progresses until an invalid hexadecimal digit
(0-9, A-F) is encountered.

:EVAL10 - Decimal String Evaluation

  ENTER: HL = Address of first char of string to convert
  EXIT : HL = Points to character terminating conversion
         DE = Contains the 16-bit binary value of string
          A = E value
  USES : AF,DE,HL

 Usage:  EVAL10 converts the string of ASCII decimal characters 
pointed to by HL into a 16-bit binary value.  Conversion 
progresses until an invalid decimal digit (0-9) is encountered.

:EVAL8 - Octal String Evaluation

  ENTER: HL = Address of first char of string to convert
  EXIT : HL = Points to character terminating conversion
         DE = Contains the 16-bit binary value of string
          A = E value
  USES : AF,DE,HL

 Usage:  EVAL8 converts the string of ASCII octal characters 
pointed to by HL into a 16-bit binary value.  Conversion 
progresses until an invalid octal digit (0-7) is encountered.

:EVAL2 - Binary String Evaluation

  ENTER: HL = Address of first char of string to convert
  EXIT : HL = Points to character terminating conversion
         DE = Contains the 16-bit binary value of string
          A = E value
  USES : AF,DE,HL

 Usage:  EVAL2 converts the string of ASCII binary characters 
pointed to by HL into a 16-bit binary value.  Conversion 
progresses until an invalid binary digit (0-1) is encountered.
