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Miscellaneous Forums => 16 bit DOS Programming => Topic started by: dncprogrammer on January 10, 2007, 03:46:22 PM

Title: More Video!
Post by: dncprogrammer on January 10, 2007, 03:46:22 PM
Hey all,
I have been reading my BIOS novel and we have made it to the section about the video routines and user fonts. Does any software use this stuff anymore?
jon
Title: Re: More Video!
Post by: MichaelW on January 10, 2007, 05:29:56 PM
I doubt that any recent software does. Although they must have existed, I cannot recall every seeing any mainstream character-mode app that used non-standard fonts. I think most of the graphics apps that were using special fonts were using a different mechanism for storing/displaying the fonts.

Title: Re: More Video!
Post by: dncprogrammer on January 10, 2007, 06:37:08 PM
Michael,
Can you possibly recommend a good book or source for learning about how windows works or even just GUI theory. I have read the undoc pc and that was interesting but not much in the way of video.
jon
Title: Re: More Video!
Post by: MichaelW on January 10, 2007, 08:52:55 PM
If you mean Windows, I know of no single book or source for learning how it works -- I think the topic is too big for that. For GUI theory I think there should be many books available, but I doubt the subject would have much to do with video hardware. For detailed information on EGA/VGA/SVGA video hardware, Richard F Ferraro's book Programmer's Guide to the EGA and VGA Cards is very good, but I suspect it's now out of print (my third edition was copyright 1994).
Title: Re: More Video!
Post by: hutch-- on January 14, 2007, 05:17:08 AM
dnc,

A long time ago you use to be able to set different BIOS fonts and its the technique was used by companies like Norton for their DOS based utilities to improve appearance while still running in CGA text mode. About 12 years ago I had all of this stuff and literally hundreds of fonts to play with but it died at the end of the DOS era and i have not seen this stuff since.

They were basically small bitmap font files that were loaded with a small utility, often with the font embedded in the utility.
Title: Re: More Video!
Post by: japheth on January 14, 2007, 01:59:41 PM

Hi,

This stuff is not outdated and it is worth to learn if you want to code other things than just boring GUI apps! The BIOS routines handling with fonts are just a very thin wrapper around the VGA hardware capabilities. And the VGA standard is still one of the most important, supported by all video cards.

Regards

Japheth



Title: Re: More Video!
Post by: dncprogrammer on January 14, 2007, 02:37:01 PM
I thank everyone for their input!
I find some of this older information and Im constantly trying to find out how much of it is still relevant in my quest to wrap my brain around how today's software works. BTW I ordered 3 more books. One is the book that Michael suggested, and two other general assembler/pc books focusing more on graphics and mouse. I have a library at this point. ALIBRIS.com I also found a copy of the Phoenix Technical Ref Series BIOS for the PC/XT/AT, wow, great reference and still looks pretty relevant for what I'm doing. Who writes reference books like that these days? ha.

jon
Title: Re: More Video!
Post by: Shantanu Gadgil on January 14, 2007, 05:36:30 PM
My two cents...
NDD for DOS does the font replacement, quite noticeably!  :bg
The non standard font has different characters as opposed to the standard ASCII/Extended ASCII charset.
(One is the radio-button like character, and the tick-mark character. There would ofcourse be many more.)

Also it changes the <Bright>RGB color values for the color registers (the 16 color palette, if you remember from DOS days).

Pretty blue colors and all!!!  :bg :bg

Cheers,
Shantanu
Title: Re: More Video!
Post by: MichaelW on January 15, 2007, 10:06:06 PM
I had forgotten about Norton Utilities, even though I had purchased at least 4 versions. There was a graphics option that ran in character-mode that provided a "graphical" look, by replacing a number of characters and implementing a simulated graphical mouse cursor. I thought the simulated mouse cursor was interesting enough to warrant investigation, and I recall determining that the 6 characters that contained the mouse cursor were being redefined on the fly, superimposing the cursor pixels on the screen pixels. They managed to make this work well even on slow hardware.