VOGONS

Search

Common searches

Search results

Display options

Display options

Re: EGA/VGA and mode Fh mono 'colors'?

Posted on 2024-02-06, 12:35

UniPCemu also fails on EGA in monochrome mode? When setting the SW1=SW2=SW4=off and SW3=on, it indeed boots up in monochrome mode. But text is never written to VRAM using the Generic Super PC/Turbo XT BIOS? Edit: OK. Blindly waited for HDD boot. It displayed one line of the MS-DOS boot menu somehow? …

Re: EGA/VGA and mode Fh mono 'colors'?

Posted on 2024-02-04, 21:21

It would be easy to test 16-color blink on a EGA or VGA device. Simply show a 16-color test pattern (squares filled with 1 color like checkit diagnostics does) and enable blink bit? Edit: Perhaps confirmed C3 being toggled on and off at least. EGA/VGA: a programmer’s reference guide [2nd ed.] …

Re: EGA/VGA and mode Fh mono 'colors'?

Posted on 2024-02-04, 20:44

C0-C3 are of course first masked by Color plane enable before any other processing into an index into the LUT. Right. The color plane enable basically masks the address bits to the attribute palette registers. The documentation mentions it uses C2 and C0 and their combination effects when MONO ( …

Re: EGA/VGA and mode Fh mono 'colors'?

Posted on 2024-02-04, 18:42

Anticipating a followup question - what tells the attribute controller to draw 9 columns? It looks like the S/L is edge-triggered. So that's the attribute controller's signal to start serializing its character and attribute input lines. I assume if doesn't receive another S/L transition that on the …

Re: EGA/VGA and mode Fh mono 'colors'?

Posted on 2024-02-04, 16:10

But unlike those lower 4 bits, the upper are always driven by the MID inputs? What are those MID inputs? M1D is the attribute byte. It's an entire byte - 3-4 bits for foreground color and 3-4 bits for background color, but as we have seen the 3rd and 7th bit gets borrowed for other purposes, …

Re: EGA/VGA and mode Fh mono 'colors'?

Posted on 2024-02-04, 15:11

I see attribute 0-3 coming from a chip that has inputs C0/MID0, C1/MID1 from sheet 6(graphics controller), but C2/C3 from sheet 7 and MID2/MID3 from sheet 6(which is the graphics controller)? sheet 6 says (graphics controller) C0/C1 outputs to C2,C3(sheet 8 )??? Perhaps the chain logic? Don't get …

Re: EGA/VGA and mode Fh mono 'colors'?

Posted on 2024-02-04, 14:53

I see attribute 0-3 coming from a chip that has inputs C0/MID0, C1/MID1 from sheet 6(graphics controller), but C2/C3 from sheet 7 and MID2/MID3 from sheet 6(which is the graphics controller)? sheet 6 says (graphics controller) C0/C1 outputs to C2,C3(sheet 8 )??? Perhaps the chain logic? Don't get …

Re: EGA/VGA and mode Fh mono 'colors'?

Posted on 2024-02-04, 10:24

Is that blinking applied to the data gotten from the sequencer (4 planes) or to the attribute controller output (what's in the registers)? Rn it's the former in UniPCemu's emulation. But does that apply with the register sets I mentioned in the first post (planes 0 and 2 being enabled only for …

Re: EGA/VGA and mode Fh mono 'colors'?

Posted on 2024-02-03, 21:48

As far as I understand mode F, it's a standard 16-color EGA mode. 32 bits from video-memory get transformed into 8 pixels of 4 bits each (sent to the AC) when then drives 6 pins in the monitor socket, which would enable EGA monitors to display 64 different colors (but EGA monitors can not …

Re: EGA/VGA and mode Fh mono 'colors'?

Posted on 2024-02-03, 13:22

I've just implemented the EGA's monitor 'DAC' (which converts the palette output to colors before applying grayscale) to use bit 3 and 4 and ignore all other bits (so shifting and masking with 3, thus getting "0,55,aa,ff" for it being "0,1,2,3" after shifting). Edit: Looking at the EGA …

EGA/VGA and mode Fh mono 'colors'?

Posted on 2024-02-03, 12:24

Does anyone know what happens when a EGA and VGA render mode Fh? https://cs.lmu.edu/~ray/notes/pcvideomodes/ Some documentation apparently say it's 4 colors (black and white and perhaps an extra bit for brightness/intensity)? If so, how does the monochrome monitor and VGA render this special case? …

Page 8 of 274

Go to top of page Go to top of page
Close window
Close window