Description:

Pop the top two bytes off the stack as an absolute (from the bottom) 0-based stack index.  Read a byte from the referenced stack location and push it onto the stack.

Pseudo Code:

absStackRef = (unsigned short)stack[sp - 2]
sp = sp - 2
stack[sp] = stack[absStackRef]
sp = sp + 1
pc = pc + 1

Flags Affected:

D	H	C	Z	N

Possible Errors:

tvmStackUnderflow	-	There were not enough bytes in the stack to get the absolute index.
tvmStackError	-	The stack index is invalid.

Example:

pushsbax

This operation pops off an index of 1.  Then it gets the byte at index 1 from the bottom (index 0) of the stack and pushes it back onto the stack.

Before stack   top 1 0x01 2 0x00 3 0x00 4 0xAA 5 0x32 6 0x02   bottom

After stack   top 1 0x32 2 0x00 3 0xAA 4 0x32 5 0x02   bottom