SM3B: A Small 3-Bit Instruction Set

2^3 = 8 instructions

Symbol	Description
0	Resets X if previous instruction not 0 or 1. Leftshifts X.
1	Resets X if previous instruction not 0 or 1. Leftshifts X and adds 1.
+	Adds X to C (accumulator) and copies the result into X
-	Subtracts X from C (accumulator) and copies the result into X
$	Swaps the values of X and Y (general purpose)
#	Swaps the values of X and M (selected memory cell)
@	Swaps the values of X and A (memory pointer)
?	Swaps the values of A (memory pointer) and I (instruction pointer) if X is not equal to zero

Example Programs

Show Comments

Name	Program
Default	Infinite Loop: 1+$@0+#1@1?Memory gets filled with numbers sequentially
Countdown	User Input: 1-@#+Countdown Loop: 101@1-? Countdown value in C
Multiplication	User Input: 1-@#$0@$#0+@#$1@$#+-$Multiplication Loop: 0+-@#+#$+$0+-1@#+1-#10101@0+?Result in Y

About the Simulator

Registers:
- X: Center
- Y: Left
- C: Top
- A: Right
- I: Top Right
- M: Bottom
Memory Map:
- 0 - 65536: General Purpose Memory
- -1: User Input (Read Only)
- All other addresses cause an error if read
Github Repository: bit-turtle/sm3b