lotto@wjh12.HARVARD.EDU (Jerry Lotto) (06/26/87)
I had to write a few procedures for someone recently that did, among
other things, a toggle of the ^PrtSc style printer echo without any
keyboard input. I never realized just how barren the DOS documentation
could be on a topic! I found a minor ref. to it in the keyboard handler
BIOS listing and a ref. under the extended scan codes tables. That's
it. I resorted to sticking the key-code into the active keyboard buffer
by hand, but this is not emotionally satisfying (although it works).
Who knows the mechanism that DOS (x.y) uses for printer echo?
A memory dump state diff. between the two was not helpful, although
the mechanism might be invisible with redirected output. Nothing
in the video driver that I found helped. The printer was out of the
reach of anyone in the room at the time!
Thanks in advance for some insight into this.
--
Gerald Lotto - Harvard Chemistry Dept.
UUCP: {seismo,harpo,ihnp4,linus,allegra,ut-sally}!harvard!lotto
ARPA: lotto@harvard.harvard.edu