The instruction set

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The fairly limited instruction set.

LDI r, nn Load register immediately Load register r with the number nn.
LD r, aa Load register. Loads the register r with the contents of cell aa.
LD r, s Load register from register Loads the register r with the contents of s.
ST r, aa Store register. Store the register r in the cell aa.
ADD r, s Add s to r. Let rr+s
SUB r, s Subtract s from r. Let rrs
JP aa Jump Jump to address aa.
JPZ Jump if zero. Jump to address aa if Z is on.
JPNZ Jump if not zero. Jump to address aa if Z is off.
JPC Jump if carry. Jump to address aa if CY is on.
JPNC Jump if not carry. Jump to address aa if CY is off.
OUT r Output r Write a to the display.
IN r Input to r. Get input 00 to 99 from the user.
SPC Space Write a space to the display.
HLT Halt. Stop the program.
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