InvitationASM is an interpreter for the assembly-styled language that is used in "An Introduction to Computer Science" by G. Michael Schneider and Judith Gersting
Python 3.6 or later
> python ExecuteIASM.py <file.iasm>An InvitationASM program consists of a series of statements, containing a token corresponding with an operation, followed by a sequence of zero or more comma-separated integer arguments for the operation. Comments are denoted by starting a line with #.
InvitationASM has several additions compared to the language used in the books. These include:
- Several new operations (indicated with italics in the operations list.)
- Dual-usage memory: One location in memory can contain two values. An executable statement, and a numeric value.
- Register address: The register has been given a memory address of -1, allowing you to use it for operations that normally work with a memory address.
- Statement anchoring: No more re-counting and re-writing jumps every time you add a line somewhere. Just drop an ANCHOR before the statement and rest assured knowing that statement will always be at that memory address.
- Extensions: Easily create and add your own operations by putting them in the extensions folder.
name: .data initialvalue
Usage: LOAD A
Loads the value contained in memory address A into the register.
Usage: OUT A
Prints the value contained in memory address A to stdout.
Usage: COMPARE A
Compares the value contained in memory address A to the value in the register. Sets the values required for JUMPGT, JUMPEQ, and JUMPLT.
Usage: STORE A
Stores the value contained in the register in memory address A.
Usage: INIT A, B
Initializes memory address A with value B.
Usage: JUMP A
Jumps to the statement contained at memory address A.
Usage: ADD A
Adds the value contained at memory address A to the value in the register.
Usage: ADD A, B
Adds the value contained at memory address A to the value stored at memory address B, and stores it back at address B.
Usage: ADD A, B, C
Adds the value contained at memory address A to the value stored at memory address B, and stores it at address C.
Usage: SUBTRACT A
Subtracts the value contained at memory address A from the value in the register.
Usage: SUBTRACT A, B
Subtracts the value contained at memory address A from the value stored at memory address B, and stores it back at address B.
Usage: SUBTRACT A, B, C
Subtracts the value contained at memory address A from the value stored at memory address B, and stores it at address C.
Usage: MULTIPLY A
Multiplies the value in the register by the value stored at A.
Usage: MULTIPLY A, B
Multiplies the value stored at B by the value stored at A, and stores it back at B.
Usage: MULTIPLY A, B, C
Multiplies the value stored at A by the value stored at B, and stores it at C.
Usage: DIVIDE A
Divides the value in the register by the value stored at A.
Usage: DIVIDE A, B
Divides the value stored at B by the value stored at A, and stores it back at B.
Usage: DIVIDE A, B, C
Divides the value stored at A by the value stored at B, and stores it at C.
Usage: HALT
Halts execution of the program.
Usage: CLEAR A
Clears the value of address A.
Usage: INCREMENT A
Increments the value of address A by 1.
Usage: DECREMENT A
Decrements the value of address A by 1.
Usage: JUMPLT A
Jumps to address A if the last COMPARE operation set LT = 1.
Usage: JUMPGT A
Jumps to address A if the last COMPARE operation set GT = 1.
Usage: JUMPEQ A
Jumps to address A if the last COMPARE operation set EQ = 1.
Usage: JUMPNEQ A
Jumps to address A if the last COMPARE operation set EQ = 0.
Usage: IN A
Reads from standard in and sets the value at A equal to what was read.
Usage: ANCHOR A
Begins inserting new instructions from memory address A.
Usage: UOUT *
Converts arguments from character codes to characters, and prints them to standard out.
Usage: SJUMP A, *
Takes in a memory address, followed by pairs of a value followed by a memory address. Compares the value in address A to the given values, and jumps to the corresponding memory address.