Description:

Pop the top byte on the stack and use it as a 1-based relative (from top) offset parameter.  Pop the new top short off the stack and place it in the stack as specified by the offset parameter.

Pseudo Code:

offset = stack[sp - 1]
shortVal = (short) stack[sp - 3];
sp = sp - 3
stack[sp - offset] = shortVal;
pc = pc + 1

Flags Affected:

D	H	C	Z	N

Possible Errors:

tvmStackUnderflow	-	There are not enough bytes on the stack .
tvmStackError	-	The stack index is invalid.

Example:

popssx

Before stack   top 1 0x02 2 0x7F 3 0x03 4 0xAA 5 0x32 6 0xFF 7 0xFF   bottom

After stack   top 1 0x7F 2 0x03 3 0xFF 4 0xFF   bottom