Mercurial > hg > Members > kono > nitros9-code
view lib/alib/asc_bin.as @ 3220:9ccec98c9897
Updated IDE Driver makefile so it will have place holders for
dsk, dskclean, and dskcopy so that make does not error out when
chaining into the driver tree to build disk images where applicable.
| author | David Ladd <drencor-xeen@users.sourceforge.net> |
|---|---|
| date | Wed, 20 Dec 2017 16:10:50 -0600 |
| parents | 03f26e88b809 |
| children |
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****************************************** * * ASCII String to binary byte conversion * OTHER MODULES NEEDED: IS_TERMIN * ENTRY: X = start of string of binary digits (001101) * terminated by space, comma, CR or null. * EXIT: D = value * CC carry set if error (string too long, not binary digits) * Y = terminator or error pos. nam ASCII String to Binary Conversion ttl Assembler Library Module section .text ASC_BIN: clra msb/lsb=0 clrb pshs a,b,x ascbn1 ldb ,x+ get a digit lbsr IS_TERMIN see if space/comma/null/cr beq ascbn2 subb #$30 strip off ASCII bmi error less than "0".. cmpb #1 BHI error geater than "1" rorb get bit into carry ROL 1,S into LSB ROL ,S into MSB inca bump string length cmpa #16 BLS ascbn1 length ok, loop BRA error ascbn2 clrb = no errors tsta len = 0? bne done no, skip * error -- too long or null error CLR ,S force data to 0 CLR 1,S ORCC #1 set carry flag done leay -1,x end of string/error char PULS A,B,X,PC get data; restore & return endsect