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[/] [ssbcc/] [trunk/] [lib/] [9x8/] [char.s] - Blame information for rev 11

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1 10 sinclairrf
; Copyright 2013, 2015, Sinclair R.F., Inc.
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;
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; Character manipulation functions
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.IFNDEF D__INCLUDED__CHAR_S__
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.define D__INCLUDED__CHAR_S__
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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;
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; Convert to and from binary.
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;
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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; Convert a single binary digit to its byte value.  Return 0x00 on success and
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; 0xFF on failure.
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; ( u_binary_n - u f )
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.function char__binary_to_byte
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  '0' -
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  dup 0xFE & .jumpc(error)
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  .return(0)
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  :error .return(0xFF)
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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;
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; Convert to and from hex.
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;
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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; Convert a byte to its 2-digit hex representation with the digit for the most
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; significant nibble at the top of the data stack.
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; ( u - u_hex_lsn u_hex_msn )
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.function char__byte_to_2hex
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  ; ( u - u u_hex_lsn )
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  dup 0x0F .call(char__nibble_to_hex,&)
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  ; ( u u_hex_lsn - u_hex_lsn u_hex_msn )
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  swap 0>> 0>> 0>> .call(char__nibble_to_hex,0>>)
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  .return
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; Convert a byte to the minimal 1 or 2 digit hex representation with the digit
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; for the most significant nibble at the top of the data stack.
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; ( u - u_hex_lsn u_hex_msn ) or ( u - u_hex_lsn )
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.function char__byte_to_hex
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  dup 0xF0 & .jumpc(include_msn)
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    .call(char__nibble_to_hex) .return
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  :include_msn
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    .call(char__byte_to_2hex) .return
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; Convert a 4 byte value to its 8-digit hexadecimal representation.
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; ( u_LSB u u u_MSB - )
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.function char__4byte_to_8hex
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  >r >r >r >r
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  ${4-1} :loop r> swap >r .call(char__byte_to_2hex) r> .jumpc(loop,1-)
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  .return(drop)
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; Convert a nibble between 0x00 and 0x0F inclusive to it hex digit.
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; ( u - u_hex_n )
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.function char__nibble_to_hex
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  0x09 over - 0x80 & 0<> ${ord('A')-ord('9')-1} & + '0' .return(+)
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; Convert two hex digits to their byte value.  Return 0x00 on success and 0xFF
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; on failure.
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; ( u_hex_lsn u_hex_msn - u f )
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.function char__2hex_to_byte
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  ; convert the msn to its position and save the error indication
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  ; ( u_hex_lsn u_hex_lsn - u_hex_msn u_msn ) r:( - f_msn )
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  .call(char__hex_to_nibble) >r <<0 <<0 <<0 <<0
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  ; ( u_hex_lsn u_msn - u ) r:( f_msn - f_lsn f_msn )
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  ; convert the lsn to its position, save the error indication, and combine the two nibble conversions
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  .call(char__hex_to_nibble,swap) >r or
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  ; compute the return status and return
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  ; ( u - u f ) r:( f_lsn f_msn - )
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  r> r> .return(or)
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; Convert a single hex digit to its nibble value.  Return 0x00 on success and
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; 0xFF on failure.
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; ( u_hex_n - u f )
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.function char__hex_to_nibble
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  dup        0x80 & .jumpc(error)
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  dup '0'  - 0x80 & .jumpc(error)
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  '9' over - 0x80 & .jumpc(not_value_0_to_9) '0' - .return(0)
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  :not_value_0_to_9
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  dup 'A'  - 0x80 & .jumpc(error)
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  'F' over - 0x80 & .jumpc(not_value_A_to_F) ${ord('A')-10} - .return(0)
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  :not_value_A_to_F
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  dup 'a'  - 0x80 & .jumpc(error)
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  'f' over - 0x80 & .jumpc(error) ${ord('a')-10} - .return(0)
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  :error .return(0xFF)
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89 10 sinclairrf
.ENDIF ; D__INCLUDED__CHAR_S__

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