[Coco] Tandy CM-8 Monitor Viewable Size

[Ron]

Hello,

I have a Tandy CM-8 monitor that seems to be working fine, however, the 
actual "viewable" area on the screen seems much smaller than it could be 
as there is quite a bit of black border around the whole picture.

Is this normal for a CM-8 or is there an adjustment that can be made 
(internally) to increase the picture size as there doesn't appear to be 
user controls to do this?

Thanks

-Ron