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View Full Version : ANSI.SYS and EGA 43-line mode



cr1901
January 30th, 2014, 10:43 PM
Tonight I discovered that mTCP IRCJr- as well as DOS- can be run in 43 line mode on my EGA monitor. The IRCJr help manual says to use your "favorite program" to change the screen mode, and quite appropriately, the MODE external command can be used to do this.

While I was searching for the correct command, I came across this article (http://www.minuszerodegrees.net/video/PC%20Magazine%20Article%20-%20The%20EGA%20board%20-%20March1986.pdf) on modem7's website, which states that 43-line EGA mode requires that ANSI.SYS not be loaded.

When I tried changing the video mode using MODE (MODE 80, 43), however, I got a message that "ANSI.SYS" is required to be loaded" to complete the command. This blatantly contradicts the article I read.

Obviously, ANSI.SYS is required, at least in PCDOS 5.0, but without having tried it myself, I would have been prone to believe that the above article was correct, and that loading ANSI.SYS would prevent certain escape codes from being interpreted correctly (such as absolutely positioning the cursor- doesn't ANSI terminal have a specific number of columns and rows anyway- and NOT 43 :P?).

To my understanding, ANSI.SYS provides support in DOS to interpret ANSI-terminal escape codes by other software. Why is DOS by itself incapable of displaying a CON with 43 lines without using ANSI.SYS? I can't fathom that special escape codes are required to change the EGA video mode and that DOS could do it on it's own. Additionally, programs like EDIT don't need the ANSI driver for 43 line mode (that much I do remember).

modem7
January 30th, 2014, 11:47 PM
In my software collection is EGA43.COM
I've put a copy [here (http://www.minuszerodegrees.net/software/EGA43.COM)]. It has been many years, but I don't remember it requiring ANSI.SYS

Chuck(G)
January 31st, 2014, 07:51 AM
I have 43-line programs; they don't require ANSI.SYS. In fact, I rarely use ANSI.SYS--ever. The only place that I see trouble is for programs that don't request the screen dimensions and simply assume 25 lines x 80 characters. Can't help that one.

JohnElliott
January 31st, 2014, 11:53 AM
Certainly DRDOS 6 can switch to 43-lines mode without ANSI.SYS loaded: MODE CON LINES=43 does it, whether or not ANSI.SYS is loaded.

Chuck(G)
January 31st, 2014, 12:56 PM
If you really need a 43/50-line capable ANSI driver, do consider NANSI.SYS (http://alumnus.caltech.edu/~dank/nansi/).

cr1901
April 14th, 2014, 03:33 PM
Sorry to resurrect this, but... does anyone know how to re-enable the text cursor in 43-line mode? EGA.COM disables it for whatever reason, unless I'm in overwrite mode (to distinguish between overwrite and insert mode)- which is certainly not what I want.

deathshadow
April 14th, 2014, 04:01 PM
Sounds like "cursor scan line start" is getting set to the 25 column location of 12, instead of the 43 column/cga position of 6. It's possible the program you used to set the mode failed to initialize it properly, as the code for switching between overwrite and insert should preserve the non-zero set value.

http://www.osdever.net/FreeVGA/vga/crtcreg.htm#0A

Shows the register that needs to be manipulated. I know some software that intercepts the keyboard itself detects EGA/VGA and then doesn't preserve the cursor settings properly for 43/50/60 column modes.

dr.zeissler
April 18th, 2017, 01:09 PM
That means ANSI Art http://bbs.ninja can be displayed on real EGA?