Tutorial
3BC is a low-level, easy-to-learn programming language that works in the form of a virtual machine similar to a 1960s computer, but with a very unusual architecture that has processors of only 3 bits.
Despite having an aspect to be an esoteric language, it has a good capacity for generic use to solve computational problems, and certain advantages with the implementation in embedded and microcontrollers.
It was introduced by a Brazilian at Christmas 2020 after completing a month of development, being a project for studies and also as a conceptual proof of concept about punched cards being readable and practical for both humans and machines.
How to make a “Hello world!”
These steps will guide you through running the hello world example and getting your first 3BC program running on your machine, so let’s get started.
After downloading the binary from download, simply unzip the file and use the command line to run the source code using the interpreter according to your operating system: windows, mac os, unix or linux.
- Examples:
helloworld.3bc
MODE NILL 0d2
STRC NILL 'o'
STRC NILL 'l'
STRC NILL 'a'
STRC NILL ' '
STRC NILL 'm'
STRC NILL 'u'
STRC NILL 'n'
STRC NILL 'd'
STRC NILL 'o'
STRC NILL '!'
- windows
using ‘terminal’ or ‘cmd’ type:
C:\Users\nicod\Downloads\3bc-windows-32> 3bc.exe helloworld.3bc
hello world!
C:\Users\nicod\Downloads\3bc-windows-32>
- mac / unix / linux
using the shell of your choice type:
$ ./3bc helloworld.3bc
hello world!
$
Structure
A great point to facilitate the learning, is its very well organized syntax of the language. With a quick view separated in rows and columns, where these have a fixed size of parameters, even when not used.
A program line is consequently an instruction, which has three mandatory parameters. They are separated in the respectively order of register, address, constant.
- Register
The register defines the behavior of the instruction be it printing to the screen, capturing inputs, summing, etc.
You should use mnemonics like mode, math and nill or some literal expressions that represent its opcode from 0 to 7. Be guided by the cheatsheet guide, which explains in detail about each instruction.
Depending on the register it is necessary to pass or not address and constant values. It can be either mandatory or restrictive, or not accept both in the same instruction, to avoid ambiguity.
- Address
Address is a space in memory used to store certain data, some instruction sets depend on it.
You must use a literal expression. It is important to note that using hash such as :my_variable in small programs is fine, but monolithic structures can have conflicts between addresses.
- Constant
Constant would be a fixed, unchanging value.
Syntax
Literal Expressions
There is no typing in the language, just raw data; For ease of use, the interpreter accepts several representations of these values, such as:
| Description | Representation |
|---|---|
| Caracter ASCII | 'Z' |
| Positive decimal | 9 0d9 0i9 |
| Negative decimal | -9 -0d9 -0i9 |
| Octal positive/negative | 0o7 -0o7 |
| Binary positive/negative | 0b1 -0b1 |
| HexaDecimal positive/negative | 0xF -0xF |
| Hash Generator | :minha_funcao |
| Zero or Null | 0 0d0 0i0 0o0 0b0 0x0 '\0' NILL |
Tags
Known as labels are markings in the program where conditional jumps or procedure calls can happen, no label can be re-labeled. It is possible to make jumps in any direction of the algorithm.
- Making markings
When both the register and address columns have null values, any constant value will be considered a bookmark.
NILL NILL 0x01
- Tagging Tip
The literal-expression hash generator is intended to make it easier to organize the labels in your code, so as not to rely on just numeric markup.
NILL NILL :loop start
- Example
MODE NILL 0d9
GOTO NILL :entry # Jump to the entry point
MODE NILL 0d2
STRC NILL 'h' # Not run
STRC NILL 'i' # Not run
STRC NILL ' ' # Not run
STRC NILL ' ' # Not run
NILL NILL :entry
STRC NILL 'f' # run
STRC NILL 'r' # run
STRC NILL 'i' # run
STRC NILL 'e' # run
STRC NILL 'n' # run
STRC NILL 'd' # run
Expected Outcome:
friend
Paradigms
Unstructured
The unstructured paradigm can be used for several occasions such as elaborating selection and condition deviations, making repetition loops, and even a complete program fast and efficient. But its overuse can bring great maintenance difficulties and unexpected behavior.
- MODE: 0d9
| name | octal | bit | description |
|---|---|---|---|
goto |
1 | 001 | jump to the label unconditionally |
fgto |
2 | 010 | jump to the label if the auxiliary memory is full |
zgto |
3 | 011 | jump to the label if the auxiliary memory is empty |
pgto |
4 | 100 | jump to the label if the auxiliary memory is positive |
ngto |
5 | 101 | jump to the label if the auxiliary memory is negative |
Repeating loops
- Infinite
Print ‘cafe’ uninterruptedly.
MODE NILL 0d2
NILL NILL :loop
STRX NILL 0xCAFE
MODE NILL 0d9
GOTO NILL :loop
- Print while
Print ‘…’ using of while.
# Value of :var is 3
MODE NILL 0d6
ALOC :var 0d3
# Print '.'
MODE NILL 0d02
NILL NILL :do_while
STRC NILL '.'
# Add -1 in :var
MODE NILL 0d8
PUSH :var NILL
MODE NILL 0d11
MATH NILL -1
MODE 0 0d08
PULL :var 0
# Repeat as long as var: is not equal to 0
MODE NILL 0d9
FGTO NILL :do_while
- While
Print ‘…’ using while.
# Valor of :var is 3
MODE NILL 0d6
ALOC :var 3
# While :var is not equal to 0
MODE NILL 0d8
NILL NILL :where_entry
PUSH :var NILL
MODE NILL 0d9
ZGTO NILL :where_exit
# Print '.'
MODE NILL 0d2
STRC NILL '.'
# Subtract 1 from :var
MODE NILL 0d8
PUSH :var NILL
MODE NILL 0d12
MATH NILL 1
MODE NILL 0d8
PULL :var NILL
# End of while
MODE NILL 0d9
GOTO NILL :where_entry
NILL NILL :where_exit
Conditional Deviation
- If Different
Print ‘!=’ if the input is different from 5.
# Keyboard capture and store in :cmp
MODE NILL 0d4
STRI :cmp NILL
# Compare the negation (:cmp != 5)
MODE NILL 0d8
PUSH :cmp NILL
MODE NILL 0d12
MATH NILL 5
MODE NILL 0d9
ZGTO NILL :if_equal
# Print '!='
MODE NILL 0d2
STRC NILL '!'
STRC NILL '='
# End program.
NILL NILL :if_equal
- If Equal, Greater or Lesser
Print ‘n<5’ if less number is less, print ‘n=5’ if number is exactly 5 or print ‘n>5’ if it is greater. Where n will be the keyboard input.
# Keyboard capture and store in :cmp
MODE NILL 0d3
STRI :cmp NILL
# Compare with 5
MODE NILL 0d8
PUSH :cmp NILL
MODE NILL 0d12
MATH NILL 5
MODE NILL 0d9
NGTO NILL :if_less
ZGTO NILL :if_equal
PGTO NILL :if_greater
# Print '<'
MODE NILL 0d2
NILL NILL :if_less
STRC NILL '<'
MODE NILL 0d9
GOTO NILL :if_exit
# Print '='
MODE NILL 0d2
NILL NILL :if_equal
STRC NILL '='
MODE NILL 0d9
GOTO NILL :if_exit
# Print '>'
MODE NILL 0d2
NILL NILL :if_greater
STRC NILL '>'
MODE NILL 0d9
GOTO NILL :if_exit
# Print '5'
MODE NILL 0d2
NILL NILL :if_exit
STRI NILL 5
Procedural
The procedural paradigm (popularly called procedural), has the advantage of making a stack of processes, where there is a return point at the same place as its call. This can make it easier to write large programs.
# Jump to entry point
MODE NILL 0d9
GOTO NILL :entry
# Procedure :print_bar
MODE NILL 0d2
NILL NILL :print_bar # Label
STRC NILL 'B'
STRC NILL 'a'
STRC NILL 'r'
MODE NILL 0d41 # Return Mode
BACK NILL NILL # Return unconditionally
# Procedure :print_foo
MODE NILL 0d2
NILL NILL :print_foo # Start of the process
STRC NILL 'F'
STRC NILL 'o'
STRC NILL 'o'
MODE NILL 0d41
BACK NILL NILL # End of process
# Entry point
MODE NILL 0d42 # Call procedures and return
NILL NILL :entry # Entry point
CALL NILL :print_foo # Call :print_foo
CALL NILL :print_bar # Call :print_bar