;**********************************
;** Function: bcd_to_byte
;** Purpose:  Convert a two-byte BCD into a single byte
;** Input: A  = Hi byte to convert 
;**                 (ASCII 0x30-0x39,0x41-0x46)
;**          R0 = Lo byte to convert 
;**                 (ASCII 0x30-0x39,0x41-0x46)
;** Output: A = Converted value (binary 0x00-0xFF) 
;** Destroyed Registers: None 
;**********************************
		  
bcd_to_byte:
    XCH     A,R0
    SUBB   A,#30h
    JNB     ACC.4,bcd_to_byte_2
    SUBB   A,#07h
bcd_to_byte_2:
    XCH    A,R0
    SUBB  A,#30h
    JNB    ACC.4,bcd_to_byte_3
    SUBB  A,#07h
bcd_to_byte_3:
    SWAP  A
    ORL   A,R0
    RET