Ram-machine

Program is a simple implementation of RAM machine.

Documentation

Code documentation is here.

Program

The ram-machine program is a set of simple instructions which can be executed by the interpeter. It should be provided as a text file using the -code (PATH) argument. It is important to note that the program parser skips all the spaces and newlines to avoid any unnecessary errors.

The program should be written with lines of code described as below:

[JUMP label], instruction, access modifier, argument, [comment];

Example program for abs is listed below:

     , READ ,  , 0    , Read value to accumulator;
     , JGTZ ,  , NOABS, If accumulator is greather than 0 jump to NOABS;
     , STORE,  , 1    , Store accumulator to register 1;
     , LOAD , =, 0    , Load 0 to accumulator;
     , SUB  ,  , 1    , Subtract value in register 1 from accumulator;
NOABS, WRITE,  , 0    , Write accumulator;
     , HALT ,  ,      , Stop;

More example programs can be found in instructions folder.

Input tape

Input tape should be provided as a text file with values separated by spaces, using the -input (PATH) argument.

Output tape

Output tape is by default set as the standard output, though it can be changed to be saved as a text file using the -output (PATH) argument.

Registers

Memory is made of registers. Register 0 is the accumulator. Other registers can be freely accessed. Registers are integers from 0 to count - 1. The register count is by default set to 100. The register count can be changed using the -registers (COUNT) argument.

Access modifier

The access modifier is used to specify how to handle the instruction argument. The instruction argument should be treated as follows:

• (nothing) - register
• = - literal
• * - register's value is pointer to other register

Supported instructions

List of supported instructions:

Instruction	Access Modifier	Argument	Description
JUMP	<nothing>	argument	jump to label argument
JZERO	<nothing>	argument	jump to label argument if accumulator is zero
JGTZ	<nothing>	argument	jump to label argument if accumulator is greather than zero
LOAD	<nothing> or = or *	argument	load value to accumulator from argument
STORE	<nothing> or *	argument	store value from accumulator from argument
ADD	<nothing> or = or *	argument	add argument to accumulator value
SUB	<nothing> or = or *	argument	subtract argument from accumulator
MULT	<nothing> or = or *	argument	multiply accumulator by argument
DIV	<nothing> or = or *	argument	divide accumulator by argument
READ	<nothing> or *	argument	read from input tape
WRITE	<nothing> or = or *	argument	write to output tape
HALT	<nothing>	<nothing>	ends program