Base64

Base64 lang is a simple esolang made by User:1048576.

We have 1 register val with default 0, and a sequence of length 512(start is a_0).

A command is two characters(12 bits when decoding in Base64 encoding):

[control(3bits)] [addr(9bits)]

(A is short for a_(addr in binary))

Control

control	meaning
000	val <- A
001	A <- val
010	A <- !(A and val)
011	if val, then jump to before A-th command running
100	Halt
101	input a bit from stdin, then save it in A

Examples

Cat program:

0180g000o0

Explanation: when it writes in binary, it looks at follows:

000 000000001 # Set val to 0
001 000000000 # Set a_0 to val(0)
010 000000000 # Set a_0 to (a_0 and val), which is 1
000 000000000 # set val to a_0(1)
011 000000000 # jump to before the first command running, so it is a cat program.