I finally manager to burn BIOS and installing it, and i worked PERFECTLY! Thank you for your bios. If anyone has a newer bios i'll reburn to original (are EPROM too!). The card worked flawlessy on a 486 ISA pc.
The problem Now is that the card didn't work an a XT clone that i was intended to use.
This is somewhat OT because i must open a new thread, but i post here also.
The problem is that the build-in CGA card cannot be disabled (like for example on IBM), and I notice that the power on light stay on a bit more. Then the screen is all-black but pc is booted. No output on original CGA.
I managed to scan the video-ram (B800:0) and the result is that all attribuite bit on text mode are 0 ZERO! So text is black on black! In addition on VGA screen is displayed a column on & column off, in vertical (attached photo).
EGA 16 color mode ok.
Note that all video mode work perfectly on a 486!
1) all text mode (hercules included) doesn't display (color 0)
2) VGA with vertical "scanline" like effect
3) EGA, 640x480x16, 800x600x16, 1024x768x4 all work
4) hercules and CGA graphics bugged with XX/00/XX/00/XX/00... Bug (1byte ok, 1byte ZERO)
5) Another VGA card (Cirrus Logic GL-CD...) work on the same machine.
6) The VGA wonder has bene set to 8-bit mode (also i/o)
7) tested with all startup video mode (text hercules, text EGA, text VGA) but black displayed (machine boot, dir work)
8) tested also with dual video card boot (vga/CGA) primary/sec but no luck!
9) EDIT: if i change 00 byte i got NO TEXT displayed! So it must read from internal RAM!!!
So my thinking are... the problem is?
1) buggy card/Bios initialization (maybe) - but BIOS is hooked correctly on interrupts (verified)
2) interference in ram with built-in CGA card?
3) some sort of byte mask? Bad bios function vector?
4) buggy 8-bit mode?
5) ram paging settings are wrong?
The interference doesn't affect EGA... (graphic mode only)
VGA 320x200x256 it's like 1 byte read from RAM, 1 byte from VIDEO RAM! page is a000-afff? 800x600x16 is good but i suspect different management.
EGA seem to use always a000-afff, except for text mode that is wrong.
Any idea? Anyone had the same problem?