Taking color mode for granted?

[rdos]

It was somebody else that first used the term "MDA". What I support is the 80x25 text mode, which is the default mode after boot for PC compatibles. Because it is the default mode after boot, virtually all video cards must support it (unless an UEFI BIOS is present, but it is frequently supported even on UEFI).

[linguofreak]

You probably know what you are talking about. However, can I ask a question? If I understood correctly, MDA was the "original" video card of IBM PC. Then there were CGA/EGA/VGA. I guess the term MDA is not relevant anymore (in any context) for modern OS developers. Is it even possible to have an 80386-based computer with MDA? Your OS surely needs an 80368 CPU or newer? Did you mean that VGA compatible cards support the MDA mode (e.g. "BIOS video mode 7h") and you support that in addition to a VGA text mode? In short: what you meant by supporting MDA?

The OP questioned whether it is safe to assume that the graphics mode at boot is color text mode with the framebuffer at B8000. As far as I know, this is a safe assumption as long as the video card supports color text mode.

I brought up the term MDA, and what I mean by supporting MDA is being able to deal with mode 7h being set at boot time (which, as far as I know, will only happen if the graphics card is an MDA).

[tom9876543]

The OP questioned whether it is safe to assume that the graphics mode at boot is color text mode with the framebuffer at B8000. As far as I know, this is a safe assumption as long as the video card supports color text mode.

I brought up the term MDA, and what I mean by supporting MDA is being able to deal with mode 7h being set at boot time (which, as far as I know, will only happen if the graphics card is an MDA).

You are wrong wrong and wrong.
Please give a web link to a Pentium or higher PC that does NOT support VGA color graphics / text mode. You can't.
So your statement is simply bullsh#t.

You then bring up "MDA" which is completely irrelevant and a total waste of time. There is not a single Pentium or higher PC that had an MDA graphics card.

It is very simple.
EVERY PENTIUM OR HIGHER PC SUPPORTS VGA COLOR TEXT AND GRAPHICS (assuming it has legacy PC BIOS).
linguofreak and others are simply talking bullsh#t.

[Combuster]

Please give a web link to a Pentium or higher PC that does NOT support VGA color graphics / text mode. You can't.

Anything without a video card will do for that:
http://h10010.www1.hp.com/wwpc/us/en/sm ... html?dnr=1

[Kazinsal]

Please give a web link to a Pentium or higher PC that does NOT support VGA color graphics / text mode. You can't.

Anything without a video card will do for that:
http://h10010.www1.hp.com/wwpc/us/en/sm ... html?dnr=1

...Well done. No on-die Intel GPU either.

[Brendan]

Hi,

You then bring up "MDA" which is completely irrelevant and a total waste of time. There is not a single Pentium or higher PC that had an MDA graphics card.

Any ISA card can be plugged into any motherboard that has ISA slots. This means that nothing prevents (e.g.) an MDA card from being plugged into a Pentium 4.

To prove that nobody has every plugged an MDA (or Hercules) video card into a Pentium or later PC, you'd probably have to ask everyone in the world if they've done this, and also ask them to agree not to do it in future (e.g. in case some geeky enthusiast decides to do it immediately after you've asked them). To be perfectly honest, I wouldn't be too surprised if there are some Pentium PCs that have both MDA and VGA (as before PCI became established this was one of the few ways to get dual monitors to work).

Of course whether or not a Pentium or later PC that has an MDA card exists is entirely irrelevant. What is relevant is whether an OS developer considers it worth supporting for their OS, and how they want to deal with unsupported hardware. For an example, my OSs typically check if the video card is "VGA or later" and if it isn't it assumes the machine has no video card at all (so if there is an MDA, it won't crash or anything, but you're going to need a serial port, serial cable and dumb terminal if you want to see anything).


Cheers,

Brendan

[linguofreak]

The OP questioned whether it is safe to assume that the graphics mode at boot is color text mode with the framebuffer at B8000. As far as I know, this is a safe assumption as long as the video card supports color text mode.

I brought up the term MDA, and what I mean by supporting MDA is being able to deal with mode 7h being set at boot time (which, as far as I know, will only happen if the graphics card is an MDA).

You are wrong wrong and wrong.
Please give a web link to a Pentium or higher PC that does NOT support VGA color graphics / text mode. You can't.
So your statement is simply bullsh#t.

You then bring up "MDA" which is completely irrelevant and a total waste of time. There is not a single Pentium or higher PC that had an MDA graphics card.

It is very simple.
EVERY PENTIUM OR HIGHER PC SUPPORTS VGA COLOR TEXT AND GRAPHICS (assuming it has legacy PC BIOS).
linguofreak and others are simply talking bullsh#t.

Read the posts I've made in this thread again. The point of those posts was to say largely what you've just said:

Any machine produced within the last 20 or 25 years that has a graphics card at all will almost certainly support color text mode.

Reason: Assuming it has a graphics card, the only way a machine will not support color text mode is if it has an MDA card. The MDA card was introduced along with the first PCs. It has been solidly obsolete since VGA was introduced. Thus it is extremely unlikely that any PC newer than 20 or 25 years old has an MDA card, and thus it is extremely unlikely that any PC newer than 20 or 25 years old does not support color text mode (unless it has no graphics card at all).