Ok got that to work but, now I can't get full screen.
fullscreen=false
fulldouble=false
fullresolution=2560x1440
windowresolution=original
output=surface
autolock=true
sensitivity=100
waitonerror=true
priority=higher,normal
mapperfile=mapper.txt
usescancodes=true
Monitor: Eizo Coloredge CG275W
If I run dosbox 072 like above I get a small screen to the left works fine.
If I put fullscreen=true
I get same small dosbox screen more in the middle with just the words no border and a red retangular square on top.
I have bought some GOG games that go full screen just fine on this monitor
7th guest 11th hour etc
Any ideas