Is it possible to extend setWatch to include timer interrupts?

Thanks @Wilberforce the up arrow in left pane more than once did the trick.

@Gordon in a previous post suggested this example:

var adder = E.asm("int(int)",
"movs r1, #3",
"adds r0, r0, r1", // add two 32 bit values
"bx lr"); // return

Gives var adder = E.nativeCall(1, "int(int)", atob("AyFAGHBH"))
and you can just use atob("AyFAGHBH"):

The "AyFAGHBH" is the 64 bit encoded version of the code.
The atob function converts it to a flat string with escaped characters.
The btoa function creates a 64 bit encoded string.

Some confusion about where to poke the string.
@Gordon suggested before the stack end address

var data = atob("AyFAGHBH");
var addr = process.memory().stackEndAddress-data.length;
poke8(addr

The assembler page suggests after the stack end address.
http://www.espruino.com/Assembler

var ASM_BASE=process.memory().stackEndAddress;
var ASM_BASE1=ASM_BASE+1/*thumb*/;
[0x4a02,0xf44f,0x4360,0x6013,0x6053,0x4770,0x0810,0x4001].forEach(function(v) { poke16((ASM_BASE+=2)-2,v); }); 
var pulse = E.nativeCall(ASM_BASE1, "void()")

So I’ve tried it both ways and both crash.

var data = atob("AyFAGHBH");
//var addr = process.memory().stackEndAddress-data.length;
var addr = process.memory().stackEndAddress+1;
for(var i=0;i<data.length;i++){
poke8(addr+i,data.charCodeAt(i));
console.log((addr+i).toString(16)+","+peek8(addr+i).toString(16));
}

var adder = E.nativeCall(1, "int(int)", atob("AyFAGHBH"));
//var adder= E.nativeCall(addr, "int(int)");

console.log(adder(2));

Which displays

>echo(0);
20009b3d,3
20009b3e,21
20009b3f,40
20009b40,18
20009b41,70
20009b42,47
5
=undefined
>