A program should be a sequence of 8, 16, or 32 hexadecimal characters. The first two characters represent the byte in memory location 0, and so on and etc.
The editor ignores whitespace and any characters on a line after a # character. So here's an example program you can submit (it's the 4-byte busy beaver described in the paper.)
31 # Subtract 1 from the accumulator
01 # NOP, also the literal value 1
70 # Jump to the first instruction if the carry bit is set
43 # Overwrite this instruction with the contents of the accumulator
8 byte instructions take the form of a 4-bit opcode and 4-bit operand
0 - NOP do nothing
1 - LDA a = M[operand]
2 - ADD a = a + M[operand]
3 - SUB a = a - M[operand]
4 - STA M[operand] = a
5 - LDI a = operand
6 - JMP pc = operand
7 - JC pc = operand if the carry flag is set
8 - JZ pc = operand if the zero flag is set
9 - invalid
A - invalid
B - invalid
C - invalid
D - invalid
E - OUT display the contents of a
F - HLT halts the machine
Disclaimer: I'm only using google sign in as lazy approach to rate-limiting, insofar as it is legally possible I will never ever use your email address at all in any way unless I ask for additional consent first, not even to email you and ask for additional consent, cross my heart and hope to die. A "delete everything you knew about me forever" button will be forthcoming, in the meantime email robsimmons+sisyphean@gmail.com to get deleted.