The argument Row may be any numeric expression. Its value gives the row (line) number where the cursor is to be moved. The argument Col may also be any numeric expression and gives the column number where the cursor is to be moved.
After a locate statement, any output directed to the screen appears at the cursorís new location.
locate 1, 1moves the cursor to the home position in the upper left-hand corner of the screen.
If the environment variable BASECHO is set to a non-null value when a Basmark QuickBASIC program begins executing, the BASIC input/output facility operates differently in order to support half-duplex terminals such as the IBM 3278. In this modified behavior of the input/output facility, the terminal modes are not altered. Locate may fail to work properly under some circumstances because of post-processing by the terminal driver.
from The Basmark QuickBASIC Programmerís Manual by Lawrence Leinweber