Bputs writes n characters from the null-terminated string, s, to the current file. The purpose of this function is to output characters at optimum speed eliminating the overhead in bputc of dealing with special characters and line wrap-around. Bputs does check for these conditions and calls bputc when necessary. A chunk of ordinary characters that fits on the current line is output quickly: for unbuffered files a single write is used (see write(2)), and for buffered files a tight loop is used. Of course, all optimizations have their costs: bputs will actually prove slower than a succession of bputc calls for a string of special characters. So bputs ought to be used thoughtfully if throughput is important.
Btermcap outputs n characters from s to the current file without interpretation and sets the line to row and the position to col. Getrow returns the line (row) number and getcol returns the position (column) number of the current file (presumably a CRT). These function support cls(misc).
Dowrite outputs n characters from s to file descriptor fd. This function supports higher level output and echoing functions.
These functions support other output functions and do not directly implement any BASIC functions.
from The Basmark QuickBASIC Programmerís Manual by Lawrence Leinweber