Date: Wed, 1 Aug 2001 19:15:00 +0300 (IDT) From: Eli Zaretskii X-Sender: eliz AT is To: "Mark E." cc: djgpp-workers AT delorie DOT com Subject: Re: djgpp: djgpp/src/libc/posix/termios/tmwrite.c In-Reply-To: <3B67E91B.32697.10BAE5@localhost> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Reply-To: djgpp-workers AT delorie DOT com Errors-To: nobody AT delorie DOT com X-Mailing-List: djgpp-workers AT delorie DOT com X-Unsubscribes-To: listserv AT delorie DOT com Precedence: bulk On Wed, 1 Aug 2001, Mark E. wrote: > I ran into a limitation I couldn't work around. I needed to scroll forward or > backward by n characters. You mean, for the feature of readline where a long line is scrolled left or right to bring the cursor position into the view without wrapping the line? > But the bios has no easy way to do this. It can be > done through bios, but it would require many calls to set the cursor, read > the character and attribute at the cursor, etc. Yes, you need to do this manually. However, I wonder: do curses and/or termcap support such operations on Unix systems? If so, what primitives do you need to implement for that? Anything beyond insert character and delete character? > And if you or someone else could clue me in on what modes require a bios-only > solution, that would be a help. All the modes up to 13h are supported by the standard BIOS. Depending on the video adapter, more modes can also be supported. ``Support'' here means mainly that the variables such as screen dimensions stored in the BIOS data area are consistent with the actual screen dimensions. Graphics modes have one complications: the cursor is not visible. But you could either ignore that, or (if you want to get fancy) emulate the cursor with a blinking underscore. (I have code that I wrote for an unreleased port of UCB Logo which does all user interaction entirely through BIOS, and it includes the cursor emulation.)