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Re: Odd video modes

Posted: Sat Jan 03, 2009 8:17 pm
by VolTeK
thanks :)

Re: Odd video modes

Posted: Sat Jan 03, 2009 10:20 pm
by Troy Martin
No problem, I often reference it myself!

Re: Odd video modes

Posted: Sat Jan 03, 2009 11:49 pm
by VolTeK
well how can i choose which one i want 01h = G or T how can i choose which mode i want, can you give me an example?
last question because i want to release my first real mode os tommarow and i will use this to my advantage

Re: Odd video modes

Posted: Sun Jan 04, 2009 11:12 am
by Troy Martin
You can't use a graphics mode as a text mode, trust me, it just doesn't work. You'd have to write your own 8x8 font so you could do 80x60 resolution, but that would mean a lot of hard work with scrolling and everything. You couldn't use your text mode routines anymore!

Re: Odd video modes

Posted: Sun Jan 04, 2009 11:49 am
by VolTeK
i know that, i just want to know why there are g and t letters there, do they have a purpose, but alright.

Re: Odd video modes

Posted: Sun Jan 04, 2009 12:05 pm
by Troy Martin
G means they're a graphics mode, T means text mode.

Re: Odd video modes

Posted: Sun Jan 04, 2009 12:31 pm
by VolTeK
darn, i would of never of had seen that right in front of me, why couldnt ralph put that on there, as definitions for the letters. he probably did, i just never knew. i tried this text mdoe last night, but every letter printed to the screen was in a different color every time, it was awsome!!!! but i knew no one would ever want it that way

btw did you see the post combuster left, that was funny, i askd him to put it back up so i could save it, but like combuster, he ignored me :| :(

Re: Odd video modes

Posted: Sun Jan 04, 2009 1:16 pm
by Troy Martin
Heh, I think I have that pic somewhere..

Re: Odd video modes

Posted: Sun Jan 04, 2009 5:33 pm
by VolTeK
what happen, did he catch you asking an unintelligent question, and then you got the "i asked the wrong question" response award, i am a "i asked the wrong question" star. ahh im kidding, let me guess... you found it at google

Re: Odd video modes

Posted: Sun Jan 04, 2009 6:23 pm
by Love4Boobies
GhostXoPCorp wrote:btw did you see the post combuster left, that was funny, i askd him to put it back up so i could save it, but like combuster, he ignored me :| :(
Then you've learned nothing from the picture. Google it! :roll: :)

Re: Odd video modes

Posted: Sun Jan 04, 2009 7:11 pm
by Troy Martin
Love4Boobies wrote:Then you've learned nothing from the picture. Google it! :roll: :)
ROFL!

Re: Odd video modes

Posted: Sun Jan 04, 2009 8:15 pm
by VolTeK
here google is god! alright, i will use google more, there i have learned my lesson :lol:

Re: Odd video modes

Posted: Fri Jan 16, 2009 11:00 am
by CPLH
hm.. how did you get into an 80x50 resolution?
With VESA, 80x60 text is the smallest.. http://lrs.uni-passau.de/support/doc/in ... B-0259.HTM
With the usual regular documented maximum of 0x13 resolution using 0x10 interrupt, the maximum is 80x30 text within VGA.

So how did you get into 80x50?

Did you manually reprogram the VGA registers?

Veniamin

Edit: Wow.. I just realized that there were more pages on this post.

Re: Odd video modes

Posted: Fri Jan 16, 2009 2:18 pm
by jal
CPLH wrote:Did you manually reprogram the VGA registers?
Iirc, the 80x50 can be set from BIOS (at least, the 8x8 character set needed is in BIOS). To get 80x60 or 90x60, you have to program the VGA registers.


JAL

Re: Odd video modes

Posted: Fri Jan 16, 2009 5:04 pm
by Troy Martin
To get 80x50, set up regular 80x25 text mode and then use ax=1112h to set up the 8x8 character font, effectively doubling the vertical text resolution.

You can also get 80x30 in real mode fairly easy by activating 640x480 graphics mode and adding a "mov bl,07h" statement before every usage of int 10h ah=0Eh. Haven't tried activating 8x8 in graphics mode though!