PWM and WDT resets

Hi, can anyone give the current state of play with PWM functions with espruin­o_1v84.tve_master_d8dec28_esp8266?
Intro states it's not yet implemented, but see code in github
https://github.com/espruino/Espruino/blob/master/targets/esp8266/jshardware.c
jshPinAnalogOutput

So I've been playing - trying getting it working. Im getting WDT timeouts when ever I call 'analogWrite' in any of its forms

analogWrite(D4, 0.5);
=undefined

Working with Web IDE so the following message gets sent to the UART

 ets Jan  8 2013,rst cause:4, boot mode:(3,3)

wdt reset

load 0x40100000, len 1396, room 16

tail 4

chksum 0x89

load 0x3ffe8000, len 776, room 4

tail 4

chksum 0xe8

load 0x3ffe8308, len 540, room 4

tail 8

chksum 0xc0

csum 0xc0

2nd boot version : 1.4(b1)

  SPI Speed      : 40MHz

  SPI Mode       : DIO

  SPI Flash Size & Map: 32Mbit(512KB+512KB)

jump to run user1 @ 1000

Tried a number of combinations:
Tried pin D14 too

D4.mode('af_output');

analogWrite(D4, 0.5,{freq:10});

D4.mode('output');

analogWrite(D4, 0.5,{freq:10});

analogWrite(D4, 0.5,{freq:100, soft:true});

analogWrite(D4, 0.5);

PS
Great project and fun to play with..