



# DosOptions
Is a options object that you pass to constructor of
[Dos](https://js-dos.com/6.22/docs/api/generate.html?page=js-dos)
class, to configure emulation layer


  

```

export class DosBoxConfig {

```







### cycles


  

```
    public cycles?: number | string;

```







   Amount of instructions DOSBox tries to emulate each millisecond.
   Setting this value too high results in sound dropouts and lags.

   Cycles can be set in 3 ways:

   * `auto` - tries to guess what a game needs. It usually works, but can fail for certain games.
   * `fixed #number` - will set a fixed amount of cycles. This is what you 
usually need if 'auto' fails. (Example: fixed 4000).
   * `max` - will allocate as much cycles as your computer is able to handle.









### autolock


  

```
    public autolock?: boolean;

```







   Mouse will automatically lock, if you click on the screen. (Press CTRL-F10 to unlock)

   By default dosbox mouse will follow browser cursor without locking.
   It means that js-dos will not take exclusive control over mouse pointer.
   However you can change this behaviour by providing `autolock=true` in
   `dosbox.conf` or throug h [DosOptions](https://js-dos.com/6.22/docs/api/generate.html?page=js-dos-options).
   Then js-dos will take exclusive control and lock mouse inside js-dos container (you can't leave it).
   This will happen after first click, and you can unlock mouse by pressing `CTRL+F10` or `ESC`.



  

```
}


```







tslint:disable-next-line:max-classes-per-file


  

```
export class DosOptions extends DosBoxConfig {


```







### onprogress


  

```
    public onprogress?: (stage: string, total: number, loaded: number) => void;

```







progress event listener, it is fired when loading progress is changed
if this function is not set, then
[auto ui](https://js-dos.com/6.22/docs/api/generate.html?page=js-dos-ui) will be used
to show progress

* `stage` - current loading stage
* `total` - total bytes to download on current stage
* `loaded` - downloaded bytes








### onerror


  

```
    public onerror?: (message: string) => void;

```







this function is called when error happens

* `message` - infomation about error








### log


  

```
    public log?: (message: string) => void;

```







you can provide log function, to override logging, by default js-dos uses console.log as implementation








### wdosboxUrl


  

```
    public wdosboxUrl?: string;

```







you can set alternative url for downloading js-dos script, default is `wdosbox.js`.
Additionaly you can change which variant of js-dos script to use:

* `wdosbox.js` - default variant. This version compiled with latest emscripten and in theory should work best
* `wdosbox-emterp.js` - This version compiled with legacy fastcomp backend, can be useful in rare cases
(e.g. if you have problems with default version)
* `wdosbox-nosync.js` - Fastest possible version, but limited. You can't run console programs/shell
emulation using it
* `dosbox.js` - same as dosbox-emterp.js because default version can't be compiled to asm.js
* `dosbox-emterp.js` - same as wdosbox-emterp.js but javascript (asm.js)
* `dosbox-nosync.js` - same as wdosbox-nosync.js but javascript (asm.js)

Take in account even if you use wasm version of dosbox it will be automatically fallbacked
to javascript version if wasm can't start.

Default version have limitation and can't be compiled to asm.js, dosbox-emterp.js will be used as fallback
for wdosbox.js


  

```
}

export const DosBoxConfigDefaults: DosBoxConfig = {
    cycles: "max",
    autolock: false,
};


```




