Bitwise IO: Difference between revisions
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* Errors handling is not mandatory
<br><br>
=={{header|6502 Assembly}}==
This routine converts a byte to a sequence of ASCII zeroes and ones, and stores them in a null-terminated string. Works in Easy6502.
<lang 6502asm>define StringRam $1200 ;not actually used in the code, but it's here for clarity.
define z_BC $00 ;fake Z80-style register for pseudo-16-bit operations.
define z_C $00 ;6502 uses the low byte as the reference point for indirect lookups.
define z_B $01 ;high byte
define tempMath $02 ;temp storage of input
define tempBitMask $03 ;temp storage of the bit filter
lda #$12
sta z_B
lda #$00
sta z_C ;load address $1200 into zero page memory for an indirect lookup.
lda #$0F ;test value
LDY #0 ;initialize offset to zero
jsr Hex2BinAscii
brk ;on easy6502 this terminates the program.
Hex2BinAscii:
sta tempMath ;store our input, in this case #$0F
lda #%10000000
sta tempBitMask
loop_Hex2BinAscii:
lda tempMath ;load input into accumulator.
and tempBitMask ;filter out all bits except the one we are checking this pass of the loop
bne bitIsOne
lda #$30 ;ascii for zero
bne StoreBit
bitIsOne:
lda #$31 ;ascii for one
StoreBit:
sta (z_BC),y ;store in StringRam+Y
loopOverhead:
iny ;y++
lsr tempBitMask ;shift to next bit in sequence
beq loop_Hex2BinAscii ;if mask is zero, we are done. BCC would have worked here as well.
lda #$00 ;load the null terminator
sta (z_BC),y ;store the null terminator after the string
rts</lang>
{{out}}
<pre>
1200: 30 30 30 30 31 31 31 31 00
</pre>
=={{header|Ada}}==
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