Simulates the pen function within 250 bytes (which I'm sure could be optimized more, if anyone wants to). The way I designed the program assumes that you have 94 as your xmax and 62 as your ymax, but you could probably change that easily. Even though this may not be of much use, it does make it simpler to erase pxls.

Basic Controls:

Arrow Keys: Move your pen

MODE: Switch between draw and erase mode

CLEAR: Stop Program

The Code:

```
:47->X:31->Y:0->C //C represents whether you are in draw or erase mode
:While 1
:getKey->K
:Pxl-On(Y-1,X //the pxls represent your cursor
:Pxl-On(Y,X-1
:Pxl-On(Y,X+1
:Pxl-On(Y+1,X
:If K or C=1
:Then
:Pxl-Off(Y-1,X
:Pxl-Off(Y,X-1
:Pxl-Off(Y,X+1
:Pxl-Off(Y+1,X
:End
:If C=1:RecallPic 1
:X-(K=24)(X>1)+(K=26)(X<94)->X
:Y-(K=25)(Y>1)+(K=34)(Y<94)->Y
:If K=22
:not(C)->C
:If C=1:Then
:Text(1,1,"pxl-on //1 space
:Pxl-On(Y,X
:StorePic 1:End
:If C=0:Then
:Text(1,1,"pxl-off //no space. This text is optional, just to show which mode you are in.
:Pxl-Off(Y,X
:End
:If K=45:Stop
:End:End
```