1bitatatime

1bitatatime was made by Benjamin F. Berger in 2026. It is a fork of Nandcode. It explores the absolute limits of computational minimalism by emulating logic gates. The language is evaluated sequentially line-by-line. The runtime enforces a strict 64-bit virtual hardware environment mapped entirely within a single physical CPU register, requiring zero RAM allocation overhead during active execution layers. Every program in 1bitatatime runs in O(N) time and O(1) space. All lines following a # are treated as comments.

1bitatatime

Designed by	Benjamin F. Berger
Appeared in	2026
Computational class	Not Turing Complete
Major implementations	Repository

Keywords

• in: declares variables as inputs at the top of the file.
• out: declares variables as outputs at the bottom of the file.
• = assigns a value to a variable.
• !& or nand evaluates bitwise nand logic: !(A & B).
• !| or nor evaluates bitwise nor logic: !(A | B).
• !^ or nxor evaluates bitwise nxor logic: !(A ^ B).
• ! or not evaluates bitwise not logic: !A.
• | or or evaluates bitwise or logic: A | B.
• & or and evaluates bitwise and logic: A & B.
• ^ or xor evaluates bitwise xor logic: A ^ B.

Note unary operators must come after their operands, e.g. `x = x !`, not `x = ! x`

Constants

true and 1 are interchangable.

false and 0 are interchangable.

Constraints

Everything runs inside a single 64-bit register in the CPU.

Bits 0 and 1 in the virtual ram are reserved for the language.

A maximum of 62 variables can be declared in total.

Examples

Swap values x and y

in: x y
temp = x
x = y
y = temp
out: x y

example: full adder [examples/swap.1bit examples/fadder.1bit])

in: a b cin
sum1 = a ^ b
sum = sum1 ^ cin
carry1 = a & b
carry2 = sum1 & cin
cout = carry1 | carry2
out: sum cout

Errors

Fatal Errors

error [1b001]: no arguments given

• cause: 1bit compiler run with no source filepath
• fix: pass a valid source as a argument for nand compiler

error [1b002]: gcc not installed

• cause: path to gcc compiler could not be found
• fix: ensure gcc is installed by running gcc --version in the folder you intend to compile from

error [1b003]: gcc failed to compile

• cause: 1bit compiler successfully created the intermediate c code, but gcc could not compile it
• fix: raise an issue on the repo

error [1b101]: not enough inputs

• cause: not enough inputs passed into compiled binary
• fix: pass the correct number of inputs into the compiled program, specified by the number of variables after in:, on the first line of your program

error [1b102]: code must end with out:

• cause: out: keyword not present in your program
• fix: add out: to the last line of your program

error [1b103]: source empty

• cause: pass empty source file to 1bit compiler
• cause: pass source file that does not contain in:
• fix: ensure your program is not empty and contains in: at the start of your program

error [1b201]: out of memory

• cause: exceed 62 assignable variable limit
• fix: try to recycle your variables by resetting their values with myVariable = 0

error [1b202]: variable undefined

• cause: using an undefined variable as an operand
• fix: define variables before using them as operands

Non-Fatal Errors (Warnings)

warn [1b401]: source does not end in .1bit

• cause: source file does not end in .1bit
• fix: rename your source file to end in .1bit

warn [1b402]: program contains no inputs

• cause: no variables declared as inputs in the in: block of your program
• fix: declare inputs in the in: block of your program

warn [1b403]: program contains no outputs

• cause: no variables declared as outputs in the out: block of your program
• fix: declare outputs in the out block of your program