 Mnemonic   | Hex | Description
 -----------+-----+-----------------------------------------------
 Add X      |  3  | Add the contents of address X to AC		
 AddI X     |  B  | Add indirect: Use the value at X as the actual 
            |     | address of the data operand to add to AC
 Clear      |  A  | Put all zeros in AC
 Input      |  5  | Input a value from the keyboard into AC
 Halt       |  7  | Terminate program
 Jump X     |  9  | Load the value of X into PC
 JumpI X    |  C  | Use the value at X as the address to jump to
 JnS X      |  0  | Store the PC at address X and jump to X+1
 Load X     |  1  | Load contents of address X into AC
 Output     |  6  | Output the value in AC to the display
 Skipcond X |  8  | Skip next instruction on condition 
            |     | (See note below.)
 Store X    |  2  | Store the contents of AC at address X
 Subt X	    |  4  | Subtract the contents of address X from AC
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 Note regarding use of SKIPCOND:
   The two address bits closest to the opcode field, bits 10 and 
   11 specify the condition to be tested. If the two address bits 
   are 00, this translates to "skip if the AC is negative". If the 
   two address bits are 01, this translates to "skip if the AC is 
   equal to 0". Finally, if the two address bits are 10 (or 2), 
   this translates to "skip if the AC is greater than 0".		

   Example: the instruction Skipcond 800 will skip the 
            instruction that follows if the AC is 
            greater than 0.
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