It's SET TEXT FONT by the way. Your code works fine for me.
sync on : sync rate 0
do
cls
set text font "arial"
set text size 20
text 20,20,"ARIAL 20"
set text font "Times new roman"
set text size 40
text 80,80,"TNR 40"
sync
loop
As mentioned though you should try and use cloggys Dll as it does superfast anti-aliased text.
Changing font in main loop in DBPro is a big no-no as it reloads the font every call. It does not cache the font at all.
You can just use the INK command to change colour, but once again DBPro really slows down if you change colours lots of times in loop.
sync on : sync rate 0
do
cls
ink rgb(255,0,0),0
set text font "arial"
set text size 20
text 20,20,"ARIAL 20"
ink rgb(0,255,0),0
set text font "Times new roman"
set text size 40
text 80,80,"TNR 40"
sync
loop
Basically the 2D capabilites of DBPro are a bit lacking in speed and could do with some rewriting, but DBPro is more about 3D games, sprites, etc which work just fine.
Boo!