The RAMPE is a relay computer with a simple custom ISA. The purpose of this project is to explore early computing and CPU design.
Included are the RASM assembler and RSIM simulator. Both are written in Fortran.
Usage: rasm <input.rasm> <output.rexe>
1 | 0, 0 | 11000000 xor a, a 2 | 0, 1 | 01110110 ll loop 3 | 0, 2 | 01000100 mov b, a ; loop address in b 4 | 0, 3 | 01111001 ll exit 5 | 0, 4 | 01001000 mov c, a ; exit address in c 6 | 0, 5 | 11000000 xor a, a 7 | 0, 6 | 00001000 loop: inc 8 | 0, 7 | 00110010 jlz a, c 9 | 0, 8 | 00010100 jmp b 10 | 0, 9 | 00000001 exit: hlt Usage: rsim [mode] [program.rexe]
rsim = run instructions from stdin
rsim <file> = run from file
Modes:
-s = single step from file (press enter)
-c = slow run from file (10 Hz clock)
-q = quietly run from file (only out instructions)
cycle: 0
a: 00000000 (0)
b: 00000000 (0)
c: 00000000 (0)
d: 00000000 (0)
ir: 11000000 (192)
pc: 00000001 (1)
cycle: 1
a: 00000110 (6)
b: 00000000 (0)
c: 00000000 (0)
d: 00000000 (0)
ir: 01110110 (118)
pc: 00000010 (2)
a = accumulator (00 in binary)
b = general purpose register (01)
c = gpr (10)
d = gpr (11)
pc = program counter
ir = instruction register
v = value, a = address, r = register
| Instruction | Purpose |
|---|---|
| nop | no operation |
| hlt | halt |
| get | pc address to acc |
| set | acc to pc address |
| sw | switch memory bank and jump |
| in | read |
| out | |
| inc | increment acc |
| dec | decrement acc |
| jmp r | jump |
| jez r, r | jump if register equals zero |
| jlz r, r | jump if register less than zero |
| mov r, r | move register to register |
| sto r, r | store register to address |
| ld r, r | load address to register |
| ll v | load immediate to al |
| lh v | load immediate to ah |
| not r | logical not |
| and r, r | logical and |
| or r, r | logical or |
| xor r, r | logical xor |
| add r, r | addition |
| sub r, r | subtraction |
| sh v, v | logical shift |
l = label
| Instruction | Purpose |
|---|---|
| la l | load label address into a |
| lb l | load label bank into a |
| lba l | load label bank and address into b and a |
| ja l | jump to label address |
| jea l | jump to label if a equals zero |
| jla l | jump to label if a less than zero |
| lda l | load from label address into a |
| sta l | store from a into label address |
| shr r | shift right |
| shrr r | shift right twice |
| shl r | shift left |
| shll r | shift left twice |
Other registers have corresponding instructions such as jeb, jlb, ldb, stb for b register.