A python implementation of the WDR paper computer
This project is meant to help coders understand just what assembly language is, and just what the CPU is doing under the hood.
With only 5 instructions, this "CPU" implementation is certainly simple. But because it includes a branching jump, it is, in fact, turing complete.
In order to use this program, you must have Python 3.5 or later installed.
Next, you need to install PyQt5. This is the window manager, style sheet, and function handler for pretty much everything (I HIGHLY recommend using PyQt5 for your projects, its designer is a joy to use.)
To install pyqt5 via pip:
$pip install pyqt5
To install via your package manager:
$sudo apt install python-pyqt5
Now you can clone this repository and start programming!
The idea of the WDR paper computer is that is a very simple system to learn the theory of computing on. The idea of a Turing machine is the ability to conditionally branch code and, by extension, change data conditionally. With this ability, one is able to solve any algorithm in this universe...given enough time, space, and brainpower.
You have the TEXT AREA and the REGISTERS. The TEXT AREA is where you type in your program. The REGISTERS are where you store and manipulate data.
If, for example, you wish to make a program that adds REGISTER A and REGISTER B and store the result in REGISTER C, you must change those registers BEFORE you run your program.
Make sure you have your numbers you want to add in A and B, and make sure C (the result) is zero before you start.
An important thing to remmber is something called the PROGRAM COUNTER. The program counter is simply a piece of memory that holds which instruction you will execute next. Program counters usually increment by +1 every time an instruction is done, and then changed completely at a JUMP to the target instruction.
In terms of the WDR paper computer, this is actually very easy to do. Each time you complete an instruction, the program counter then moves down +1 lines, and executes THAT instruction. If you come across a JUMP or an ISZ instruction, the program counter behaves differently as described.
[R] - Register [L] - Line number
Syntax: INC [R]
This instruction increments the target register by 1.
Syntax: DEC [R]
This instruction decrements the target register by 1. Note that one is unable to have a negative in a register.
Syntax: ISZ [R]
This instruction checks to see if the target register is zero. If [R] is zero, then increment the program counter +2 lines. If not, then increment the program counter +1 line.
Syntax: JMP [L]
This is an unconditional jump to line number [L]. It changes the program counter to line number [L].
Syntax: STP
This instruction halts the computer's execution.
- helloworld.txt
- Toggles Register A from 0 to 1 and back, forever.
- unsigned_2way_multiply.txt
- A non-working example.
- unsigned_multiply.txt
- Multiplies contents of Register A by Register B and puts the result in Register C.
- \boolean*.txt
- These examples do boolean functions on Register A and Register B.
- simple arithmetic\signed_subtract.txt
- Subtracts Register B from Register A. If negative, Register X is flagged.
- simple arithmetic\simple_add.txt
- Adds Register A to Register B.
- simple arithmetic\simple_subract.txt
- Subracts Register B from Register A.