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IBM 5155 EGA card video seven and OCTEK oti037c

What is the chip EPROM for this card ?
The VGA BIOS is split to two EPROM mays be is two 27128 or 27127 ?
The BIOS of the VGA card will reside at address C0000.

Something that often (not always) works is:
1. Run DEBUG per [here], except type in "dc000:0"
2. Note the third byte (10 in the example pointed to).
3. To work out the code size, convert the third byte from hex to decimal, then multiply that by 512 bytes.

E.g. 40 hex = 64 decimal. 64 x 512 bytes = 32 KB. A code size of 32 KB suggests two 16 KB ROM's (e.g. two of 27C128).

E.g. 30 hex = 48 decimal. 48 x 512 bytes = 24 KB. A code size of 24 KB suggests two 16 KB ROM's (e.g. two of 27C128).
 
I thought the address of a VGA card started at A0000,

it's going to give me a problem because I have an XT-IDE Rev 4.1 card and the address is C0000, I believe.

I cannot change the address range of the video card.

if so, I would have to reconfigure the XT-IDE EEPROM card, format the SD card and reinstall everything.

[EDIT]
The default EEPROM address is D0000, but I don't remember if I modified it.

on the blue lava system site it is indicated that the default value is D0000, but on the image it is set to C0000 (switch: 11000000)
 
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I thought the address of a VGA card started at A0000,

The native EGA/VGA graphics modes reside there. The color text/CGA compatible graphics modes are at B8000, just like the real thing.

And yes, if you have another ROM at C0000 you will almost certainly need to move it. I’ve never seen a VGA card with a relocatable BIOS.
 
I put my oak oti 037c card, I changed switch 5 and 6 to On and it works fine.

On the other hand, I'm surprised that I had to put the video card jumper on the 16 bit bus, because in 8 bit mode it didn't work,
black screen and a long beep.

On the other hand there are bands on the screen, the card works well because I tested it on a 486, the screen works well because I tested it in CGA and I use it with an ESP32 VGA , maybe there is a setting made on the screen.

It's an NEC Accusync LCD71vm screen, which recognizes all frequencies, because I used it in CGA without problem.

There is a jumper on the ati 037c video card to put irq 2 in enable or disable, should I put it in enable or leave it in disable?

here image with bands on screen
image 1

image 2

[EDIT]
I just tested on another screen and it works very well without band,
however the NEC screen works well without any problem and without band on a 486, or an old toshiba laptop in vga
 
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I just noticed one thing on the photo from image1 link, a piece of the screen is missing on the right.

On my NEC screen it says:
31.4Khz /70.0Hz
720x400
Why 720x400?
do I have to install a driver under dos like the VESA?
is it possible to change the resolution with a command under dos?
 
31.4Khz /70.0Hz
720x400
Why 720x400?
do I have to install a driver under dos like the VESA?
is it possible to change the resolution with a command under dos?

That is the standard VGA text mode. (The CGA/EGA backwards compatible modes also run at 70hz, only 640x480 graphics runs at 60hz on a standard VGA.)

As for the lines, fiddle with your monitor’s onscreen menu and look for an ‘auto adjust’ function, or see if there are manual sync adjustments. The sad fact is that most cheap LCD monitors do a cruddy job displaying VGA text mode. The companies that made them assumed you’d be running Windows.)
 
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