Flush Screen Output Buffer
Tab(-1,254) does nothing under AMOS, which doesn’t buffer screen output. But under both Windows and Unix, A-Shell output is buffered to minimize system overhead. The buffer is flushed after nearly every Tab(-1,x) command and every carriage return, as well as before every input. Under Windows, the buffer is also flushed every half second or so. Usually, the effect is not noticeable. But in some circumstances, you may find it annoying. One case in particular is where a report program displays “life signs” -- either a dot for every few records processed, or a % complete indicator. If the PRINT statement updating this display has a semicolon on the end (to suppress an unwanted carriage return), then instead of seeing a steadily updating indicator, it may appear as if nothing is happening, and then all of a sudden, it goes from 0 to 100% in one jump. Adding a Tab(-1,254); on the end of these PRINT statements (e.g. PRINT “.”;Tab(-1,254);) will make the output display as expected.
