Bitwise IO: Difference between revisions
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→Storing Bytes As ASCII Strings
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This routine converts a byte to a sequence of ASCII zeroes and ones, and stores them in a null-terminated string. Works in Easy6502.
Multiple bytes can be stored this way simply by loading a new value in the accumulator and calling the subroutine again. Since Y is still pointed at the null terminator, no re-adjustment of <code>z_BC</code> or Y is necessary.
<lang 6502asm>
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.
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1200: 30 30 30 30 31 31 31 31 00
</pre>
===Compressing a String of ASCII Zeroes and Ones===
Building on the above, the process can be reversed. The output of the first function becomes the input of the second. Some of the above is repeated, this is to show the two working in sequence.
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