w832

A sample instruction set, assembler, and emulator. Uses 3 bit opcodes and 5 bit memory addresses. Can address 32 bytes of memory.

Dependencies

A POSIX C compiler, probably requires GCC. Untested on Windows.

Building

make run

Assembling Programs

editor prog.asm
bin/w832_asm prog.asm prog.bin
bin/w832_sim prog.bin

Assembly Language Reference

All instructions can act on the memory, program counter, and the primary register A (the only general purpose register).

• LOD n LOAD value from memory address N into register A.

• STO n STORE register A in memory address N.

• CMP n COMPARE register A to memory address N. Skip next instruction if equal.

• JMP n JUMP PC to memory address N.

• ADD n ADD value from memory address N to register A.

• NEG TWOS COMPLEMENT NEGATE value in register A.

• AND n AND value from memory address N with register A.

• NOT BINARY NEGATE value in register A.

• 0x[0-F]+ will insert a literal hexadecimal value into memory.

• [0-9]+ will insert a literal decimal value into memory.

• 0[0-9]+ will insert a literal octal value into memory.

• ORG n Only affects assembly process. Places the following instruction at memory location n, the one after that at n+1, and so on.

Example Program

This program counts by 4's in the addresses 16-31

LOD 16
ADD 16
STO 17
LOD 2
ADD 15
STO 2
LOD 0
ADD 15
STO 0
JMP 0

ORG 15
0x01
0x04

Credits

Inspired by c88, which is based on the SSEM. I also have a modified fork of c88 called c1616.