A simple program to show use of the SKN and JMP instructions.

Description:	Load X into the Accumulator and decrement the accumulator until it goes negative.
Parameter Lines:	31: X
Result Lines:	-

01: LDN 31  -- A = -X
02: STO 29  -- store -X
03: LDN 29  -- A = -(-X) = X
04: SUB 30  -- A = A-1
05: SKN     -- skip if A < 0
06: JMP 28  -- otherwise go to line 4
07: HLT     -- done, A has gone negative

28: NUM 3   -- jump address
29:         -- -X
30: NUM 1   -- decrement
31: NUM 7   -- X Parameter