Testing all video mode - but which ones are graphics ?

[R.Wieser]

Hello all,

I've got a small program going thru all video-modi by looping AL from 80
upto FF, calling INT 10, AH=00.

I would like to find out which of those modi are graphical. Ralf Browns
memory list shows 0040:0065 to hold some bits regarding the current video
mode. In my case the lower two bits are of interrest

Mode 03, text, shows the value 01. Alas, mode 0D, graphics, also shows 01.
In fact, only modi 4 thru 6 show a 02 there, and modi 0 and 01 show a 00.
Al others show 01.

And I'm pretty sure there are few other graphics modi above mode 06 ...

tl;dr:
How do I find out if a certain mode is graphics ?

Secondary question : if the lower two bits of 0040:0065 are *not* the
current video-modes graphics and textmode capablities, what do they signify
instead ?

Regards,
Rudy Wieser

[JJ]

Post by R.Wieser
Hello all,
I've got a small program going thru all video-modi by looping AL from 80
upto FF, calling INT 10, AH=00.
I would like to find out which of those modi are graphical. Ralf Browns
memory list shows 0040:0065 to hold some bits regarding the current video
mode. In my case the lower two bits are of interrest
Mode 03, text, shows the value 01. Alas, mode 0D, graphics, also shows 01.
In fact, only modi 4 thru 6 show a 02 there, and modi 0 and 01 show a 00.
Al others show 01.
And I'm pretty sure there are few other graphics modi above mode 06 ...
How do I find out if a certain mode is graphics ?

Easy way: Use BIOS service to read a pixel. It's only applicable in graphic
video mode.

Hard way: Use the video ports to check the current type of video mode. i.e.
graphic or text.

Post by R.Wieser
Secondary question : if the lower two bits of 0040:0065 are *not* the
current video-modes graphics and textmode capablities, what do they signify
instead ?

See Ralf Brown's Interrupt List.

[R.Wieser]

JJ,

Post by JJ

Post by R.Wieser
How do I find out if a certain mode is graphics ?

Easy way: Use BIOS service to read a pixel.
*It's only applicable in graphic video mode.*

(bolding mine)

Indeed. And, AFAICT, that means that *you should not be trying to use it*
in a non-graphics mode.

It also says squat about what happens if you do try. Which makes it
useless.

Post by JJ
Hard way: Use the video ports to check the current type of video
mode. i.e. graphic or text.

And you don't think that suggestion is a bit ... vague ?

Post by JJ

Post by R.Wieser
Secondary question : if the lower two bits of 0040:0065 are *not* the
current video-modes graphics and textmode capablities, what do they signify
instead ?

See Ralf Brown's Interrupt List.

You're a funny guy. Not.

Whats the matter ? Did you step outof bed with the wrong foot first ? :-(

Regards,
Rudy Wieser

[JJ]

Post by R.Wieser
JJ,

Post by JJ

Post by R.Wieser
How do I find out if a certain mode is graphics ?

Easy way: Use BIOS service to read a pixel.
*It's only applicable in graphic video mode.*

(bolding mine)
Indeed. And, AFAICT, that means that *you should not be trying to use it*
in a non-graphics mode.
It also says squat about what happens if you do try. Which makes it
useless.

Post by JJ
Hard way: Use the video ports to check the current type of video
mode. i.e. graphic or text.

And you don't think that suggestion is a bit ... vague ?

Post by JJ

Post by R.Wieser
Secondary question : if the lower two bits of 0040:0065 are *not* the
current video-modes graphics and textmode capablities, what do they signify
instead ?

See Ralf Brown's Interrupt List.

You're a funny guy. Not.
Whats the matter ? Did you step outof bed with the wrong foot first ? :-(

Can't give fish all the time. You gotta fish yourself eventually.

[R.Wieser]

JJ,

Post by JJ
Can't give fish all the time. You gotta fish yourself eventually.

You know me better than that.

Besides, how do you think I found that 0040:0065 reference ?

But tell me, how come you're assuming that I didn't fish for myself ?

And by the way, nice ignoring me on calling you out on your 'peek a pixel'
suggestion.


Something odd is going on here, and I'm not at all sure anymore that you
really are JJ.

Regards,
Rudy Wieser

[wolfgang kern]

Post by R.Wieser
I've got a small program going thru all video-modi by looping AL from 80
upto FF, calling INT 10, AH=00.

ask again in ALA

[R.Wieser]

Wolfgang,

Post by wolfgang kern

Post by R.Wieser
I've got a small program going thru all video-modi by looping AL from 80
upto FF, calling INT 10, AH=00.

ask again in ALA

alt.lang.ass I presume ? Really ? Half of it seems to be spam. But hey,
I've got little to lose.

Regards,
Rudy Wieser