A bit dim about "DIM"

[OldMoses]

I think what you're looking for is DEFINT, DEFSGN, DEFLNG, DEFDBL & DEFSTR.

You can define a range of variables starting with certain characters AS a certain type variable, for example:
DEFSNG A - G

would define all variables starting with A thru G as singles. I believe it's a holdover from the days of limited memory and is mostly to maintain code compatibility. I never use it, myself.