README

JASM

Johnny Simulator Assembler Compiler that generates .ram files for https://sourceforge.net/projects/johnnysimulator/

Running and compiling JASM

To compiler jasm just call make in the main folder. To run it, simply call it with the filename as first argument. It will output a file called a.ram

Programming in JASM

Labels

Labels are a way to reference a specific position in memory. You create them like this:

label: <>

DB

You use DB to define a value in a specific memory location. In order to reference it later, you can precede it by a label.

MyImportantVariable: DB 100

Operations

TAKE takes a value from memory - Arguments: position (integer) or label

SAVE saves a value to memory - Arguments: position (integer) or label

ADD adds a memory cell to ACC - Arguments: position (integer) or label

SUB subtracts a memory cell from ACC - Arguments: position (integer) or label

INC subtracts a memory cell - Arguments: position (integer) or label

DEC subtracts a memory cell - Arguments: position (integer) or label

NULL sets a memory cell to 0 - Arguments: position (integer) or label

TST tests if a memroy cell is 0 and skips the next memory cell if it is - Arguments: position (integer) or label

JMP Jump to a memory cell - Arguments: position (integer) or label

HLT stop execution - Arguments: no arguments

Example Programs

Multiply two variables with eachother

loop: TAKE result
ADD mul1
SAVE result
DEC mul2
TST mul2 ; mul2 is zero once mul1 was added enough times
JMP loop
HLT
mul1: ;labels can be on their own in a line
DB 3
mul2: DB 4
result: DB 0