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CPM OPERATING SYSTEMS/CPM 2.X/CPM 2.2/PATCHES/ZSID.BUG

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+                                ZSID BUGS
+
+From DDJ, Oct. 1982, p. 7
+
+ZSID doesn't interpret the LDIR instruction correctly when the
+operands (the two strings defined by the HL, DE and BC registers)
+overlap on each other. The LDIR (long move) instruction of the
+Z-80 copies a source string into a target string. When the target
+string overlaps on the source string (as when the source begins
+at 200h, the target at 201h and the length is 255 bytes) LDIR
+becomes a Replicate instruction, duplicating the leading byte
+of the source into the target over and over. ZSID doesn't handle
+it right, though; it stops after copying one byte.
+
+Also, the disassembler in ZSID doesn't seem to handle the LD A,R
+and LD R,A instructions. Its List command won't display them and
+its Assemble command won't accept them.
+
+The number -1 is not correctly interpreted. For example, LD HL,-1
+is interpreted as LD HL,00FF.
+