- There are 256 registers, which store 16 bit unsigned integers.
- There are 65536 words (16 bits) in memory.
- All instructions are 2-byte aligned.
- The return stack has a maximum depth of 254.
denote registers R and S
- [S] denotes memory with address at the value of S
- @A@ denotes the instruction at position A
Instruction | Byte | Format | Operation
ret | 00 | 00__ | Return (or terminate) gsb @A@ | 0F | 0F__AAAA | Go to subroutine at A
| AA | AA--RRSS | Load from [S] into R
sto | AF | AF--RRSS | Store R at [S]
inc | CA | CARR | Increment R jzd @A@ | CB | CBRRAAAA | Decrement R if R > 0, else jump to A jmp @A@ | CF | CF--AAAA | Jump to A
| EA | EASS | Output from [S]
rdc | EF | EFSS | Input to [S]
[FFFF]: stack counter [FFFE]-[FF00]: return stack [FEFF]-[????]: instruction memory [addr]-: data memory
addr is stored in register FF