/* * mu808: an ultralight numeric-only VM * This is the core JS file for the reference implementation * of mu808 VM for the Web and other ES5 engines * See the README.md file in the repo root for all documentation * Created by Luxferre in 2025, released into public domain */ /* Due to the modular nature, this file only defines the mu808 VM kernel * which accepts all I/O routines as the parameters for its construction */ function createmu808(lineOut, charOut, lineIn) { var MEMLIMIT = 16384, PMEM = new Uint16Array(MEMLIMIT << 2), /* program memory */ DMEM = new Float64Array(MEMLIMIT), /* data memory */ runlimit = MEMLIMIT, traceflag = false, runcount = 0 /* memory range input function */ /* accepts the continuation callback as the last parameter */ function dataRangeInput(start, end, contfunc) { (function inp(loc) { lineIn(function(v) { DMEM[loc] = parseFloat(v) || 0.0 if(loc < end) inp(loc+1) else { if(contfunc) contfunc() } }) })(start) } /* port output function */ function portout(port, data) { if(port == 0) lineOut(data + "\n") else if(port == 1) charOut(data & 255) } /* instruction line execution function (the main 808UL logic defined here) */ /* accepts the continuation callback as the last parameter */ function ilexec(lno, cmd, x, y, z, contfunc) { var halt = 0, data_override = 0, bcheck, i, v1, v2, v3 while(halt == 0) { v1 = v2 = v3 = data_override = DMEM[0] = 0 /* force the value at 0 to be always 0 */ DMEM[127] = 1 /* force the value at 127 to be always 1 */ if(lno == 0) halt = 1 /* immediate instruction */ if(runlimit > 0 && runcount > runlimit) { halt = 1 if(traceflag) lineOut("Runlimit hit, halting...\n") } else runcount++ if(traceflag) lineOut("PC: " + lno + " INSTR: " + [cmd, x, y, z].join(" ") + "\n") bcheck = (x < MEMLIMIT) && (y < MEMLIMIT) && (z < MEMLIMIT) if(bcheck) { /* boundary checks passed */ v1 = DMEM[x]; v2 = DMEM[y]; v3 = DMEM[z] /* prefetch the memory values */ if(cmd == 1) { /* JMP */ if((v2 == 0 && x == 0) || (v2 > 0 && x == 1) || (v2 < 0 && x == 2) || (v2 >= 0 && x == 3) || (v2 <= 0 && x == 4) || (v2 != 0 && x == 5) || x == 6) { halt = 0; lno = z - 1 } else if((v2 == 0 && x == 7) || (v2 > 0 && x == 8) || (v2 < 0 && x == 9) || (v2 >= 0 && x == 10) || (v2 <= 0 && x == 11) || (v2 != 0 && x == 12) || x == 13) { halt = 0; lno = (v3|0) - 1 } } else if(cmd == 2) data_override = 1 /* IAT */ else if(cmd == 3) for(i=x;i<=y;i++) portout(z, DMEM[i]) /* OUT */ else if(cmd == 4) { /* INP */ dataRangeInput(x, y, function() { /* continuation function duplicating what's after the switch */ /* except the data override branch */ lno++ /* increment the program counter */ if(lno >= MEMLIMIT || lno < 1 || (runlimit > 0 && runcount > runlimit)) { if(traceflag) lineOut("Memory limit or runlimit hit, halting...\n") halt = 1 } else { /* fetch the next instruction and execute it */ cmd = PMEM[lno << 2] x = PMEM[(lno << 2) + 1] y = PMEM[(lno << 2) + 2] z = PMEM[(lno << 2) + 3] ilexec(lno, cmd, x, y, z, contfunc) } }) return } else if(cmd == 5) DMEM[z] = (x % 10000) + (y % 10000) / 10000.0 /* SET */ else if(cmd == 6) { /* CPY */ if(x == 0) DMEM[z] = y else if(x == 1) DMEM[z] = v2 else if(v2 < MEMLIMIT && v3 < MEMLIMIT) DMEM[0|v3] = DMEM[0|v2] } else if(cmd == 7) DMEM[z] = v1 + v2 * v3 /* FMA */ else if(cmd == 8) DMEM[z] = v1 - v2 /* SUB */ else if(cmd == 9) DMEM[z] = (v2 == 0) ? 0 : (v1 / v2) /* DIV */ else if(cmd == 10) DMEM[z] = (v2 == 0) ? (0|v1) : ((0|v1) % (0|v2)) /* MDF */ else if(cmd == 11) DMEM[z] = Math.abs(v2) /* ABS */ else if(cmd == 12) DMEM[z] = Math.sqrt(Math.abs(v2)) /* SQR */ else if(cmd == 13) { /* NEL */ if(x == 0) DMEM[z] = Math.exp(v2) else DMEM[z] = (v2 == 0) ? 0 : Math.log(Math.abs(v2)) } else if(cmd == 14) { /* TRI */ if(x == 0) DMEM[z] = Math.sin(v2) else if(x == 1) DMEM[z] = Math.cos(v2) else DMEM[z] = Math.atan(v2) } else if(cmd == 15) { /* RND */ v1 = 0|v1 DMEM[z] = v1 + (0|(Math.random() * ((0|v2) - v1 + 1))) } } /* command switch ends here */ lno++ /* increment the program counter */ if(lno >= MEMLIMIT || lno < 1 || (runlimit > 0 && runcount > runlimit)) { if(traceflag) lineOut("Memory limit or runlimit hit, halting...\n") halt = 1 } else { /* fetch the next instruction */ if(data_override && bcheck) { cmd = PMEM[lno << 2] x = (0|v1) % MEMLIMIT y = (0|v2) % MEMLIMIT z = (0|v3) % MEMLIMIT } else { cmd = PMEM[lno << 2] x = PMEM[(lno << 2) + 1] y = PMEM[(lno << 2) + 2] z = PMEM[(lno << 2) + 3] } } } if(contfunc) contfunc() } /* instruction line entry function (interactive mode) */ /* accepts the continuation callback as the last parameter */ function ilenter(lno, cmd, x, y, z, contfunc) { if(lno > 0) { /* record the instruction in memory */ PMEM[lno << 2] = cmd PMEM[(lno << 2) + 1] = x PMEM[(lno << 2) + 2] = y PMEM[(lno << 2) + 3] = z if(contfunc) contfunc() } else if(lno == 0) { /* immediate execution */ runcount = 0 ilexec(lno, cmd, x, y, z, contfunc) } else if(lno == -1) { /* display a range of instructions from cmd to x */ if(cmd < MEMLIMIT && x < MEMLIMIT) for(y=cmd;y<=x;y++) { z = y << 2 lineOut("@" + y + ":\t" + [PMEM[z], PMEM[z+1], PMEM[z+2], PMEM[z+3]].join(' ') + '\n') } if(contfunc) contfunc() } else if(lno == -2) { /* clear a range of data or instructions from x to y */ if(cmd < MEMLIMIT && x < MEMLIMIT) for(z=x;z<=y;z++) { if(cmd == 0) PMEM[z*4] = PMEM[z*4+1] = PMEM[z*4+2] = PMEM[z*4+3] = 0 else DMEM[z] = 0.0 } if(contfunc) contfunc() } else if(lno == -3) { /* tracing on/off */ if(cmd == 0) {traceflag = 0; lineOut("Tracing off\n")} else {traceflag = 1; lineOut("Tracing on\n")} if(contfunc) contfunc() } else if(lno == -4) { /* set the runlimit to the value of cmd */ runlimit = cmd lineOut("Runlimit set to " + cmd + "\n") if(contfunc) contfunc() } else if(lno == -5) { /* can't exit to the environment, reset instead */ lineOut("Resetting the machine...\n") for(y=0;y