Hi, I wondered what CLS should do while CTTY points to "not CON". Any ideas? I could not find it by Googling, so I assume that people will simply not try using CLS over a serial terminal... Or if they do
- the CLEAR / HOME ANSI escape sequence or - a bunch for linefeeds or - a formfeed should do the trick. As CTTY targets can only be CON, NUL and serial ports (parallel ports would not make much sense) or other bidirectional char devices, I think one of the above choices should be okay. Alternatively, even "just always clear the local display even during CTTY non-CON" should work just great for everyday CTTY / CLS users. Instead of using the CRT unit function, which never updates the screen size stuff as it seems, CLS for CON can best be implemented as: AH=0f int 10 returns: AH=columns AL=mode BH=page read byte 40[84] = max row number on screen AH=06 (scroll) AL=0 (zero lines of scrolling, only clear) BH=07 (color, for blank lines, should not be zero) CX=0 (upper left corner) DH=40[84] DL=the_AH_from_int_10_function_0f int 10 (might destroy BP register but has no return values otherwise... Trident VGA might destroy DS register in SVGA modes...) And finally, not to forget, AH=02 BH=the_BH_from_int_10_function_0f DX=0 (top left) int 10, which moves the cursor to home position. The int 10.0f can be replaced by 40[...] reading, too. Combined, you will have a TINY and RELIABLE (flexible, for different screen sizes, see Bugzilla entry number 1687, CLS Assumes 25 Screen Lines) implementation of CLS which does not use the CRT library of the C compiler (and therefore the whole CRT library would no longer be used by FreeCOM anymore AFAIK). The above { get mode by int 10.0f, get rows from RAM, clear by int 10.06, home by int 10.02 } should be put after a check for CTTY-non-CON which would send one of the 3 suggested strings either instead of doing the int 10 stuff or after it to the current CTTY device unless it is CON/NUL. Let us know if you have some experience or opinion about "what should happen for CLS in combination with CTTY to AUX or NUL or ...". Thanks. Eric ------------------------------------------------------- This SF.Net email is sponsored by the new InstallShield X. >From Windows to Linux, servers to mobile, InstallShield X is the one installation-authoring solution that does it all. Learn more and evaluate today! http://www.installshield.com/Dev2Dev/0504 _______________________________________________ Freedos-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/freedos-devel