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IBM 5155 EGA card video seven and OCTEK oti037c

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andromeda92

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Hi,
there are 2 8 bit isa cards, Video Seven 600-0102 Cirrus Logic Chip CL-GD410 / GD420 and Video Seven 650-0095 VEGA VGA Cirrus Logic cl-gd510a / 520a and a 16bit OCTEK oti037c isa, which of these three cards works with an IBM 5155 with NEC CPU V20.

Do these EGA / VGA video cards run on a 16bit isa bus on a 486 motherboard.

thanks for your help.
 
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The 8 bit ones should work without problem on the 5155, as they are designed for that kind of system. Rearding the Octek, I recently bought one for my PS/2 Model 30 8086 and it works flawlessly (although slow as hell...)
 
thanks ou for your response for ibm 5155 but these card it seem not work on 486 motherboard ?
octek oti 037c card exist on 8bit isa and 16bit isa, these work on ibm 5155 ?
 
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Sorry, I have no response for the 486, as I know them, I really never owned one so I can't tell.

Regarding the Octek, mine is 16 bits and works great on a 8 bit slot. If there's a 8 bit model, it should work too.
 
I will receive a 16 bit oti 037c card (VGA, EGA, CGA) in 16 bit (1037162003 rev.A) , there are two blue jumpers, at botoom left
I think it is these switches to put it in 8 bit.
The switches are already set for vga and the card was used in 16bit ISA mode.

Do I have to remove the original card, to put the new oti 037c card, so that there are no memory addressing conflicts?

Do I have to change the jumpers on the IBM 5155 motherboard?

I forgot to mention that I had a NEC 20 on the IBM 5155, not sure it would work with this card.

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There should not be any memory addressing conflicts switching from a VGA to EGA card, unless it is in software because you are using upper memory blocks for EMS or something.

I don’t think you can use two video cards at the same time. There would almost certainly be some conflict.

The switches on the 5155 motherboard for using an EGA and a VGA card are the same.

The NEC V20 CPU should not affect compatibility.
 
so if I use the oti 037c card in vga, I must remove the video card from the ibm 5155 (CGA), and I do not modify the switches on the motherboard?
 
andromeda92 said:
and I do not modify the switches on the motherboard?
Click to expand...

Here are the switch settings for the 5160, 5155 uses the same motherboard:


Technically you are supposed to change switch settings when you replace a CGA card with EGA/VGA. It *may* work anyway in my experience, but that experience was a long time ago.

Obviously you’ll be killing the internal monitor on your 5155 with this upgrade unless you’re using a very special VGA card with a composite output.

(ATI made EGA cards that could drive the internal monitor, that’s about it.)
 
1) So the best is that I remove the CGA card from the IBM 5155, that I modify the parameters of the switch in VGA and that I put my new card OAK OTI 037C.

2) I didn't think there was an ATI video card that could drive the IBM 5155 internal screen. So the IBM 5155 screen supports EGA in monochrome
 
Sorry I thought you said ega. Usually there is a MDA/monochrome setting, a CGA setting and an EGA/VGA setting.


I jjust posted this in another related thread but here you go. The card is called an ATI EGA wonder 800+. There are other variants of this card with the four pin connector not present so if you are looking for the card make absolutely sure you are getting the right one.
 

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andromeda92 said:
1) So the best is that I remove the CGA card from the IBM 5155, that I modify the parameters of the switch in VGA and that I put my new card OAK OTI 037C.
Click to expand...
Yes - see below.

As an experiment, I have just now tried CGA+VGA. Results follow, and it shows at least one problem.

I no longer have an IBM 5155, but I have an early IBM 5160. The early IBM 5160 has the same motherboard, and same BIOS revision, as the IBM 5155. My early IBM 5160 has an IBM CGA card fitted, just like the IBM 5155. I also have two different VGA cards that are compatible with the IBM 5155/5160.

I added the first compatible VGA card and connected a VGA display to it (i.e. computer contains both an IBM CGA card and a 5155/5160 compatible VGA card).

At power on, the VGA display is the 'active' display (screen changes go to it). It shows the RAM count-up, etc. The CGA display only shows a flashing cursor.

If I then enter "mode co80", the CGA display becomes the 'active' display - a "C:>" prompt appears on it, and screen changes go to it. No further screen changes are seen on the VGA display.

But a problem I saw is that the VGA display showed programs in monochrome (no colour). There may be other problems as well.

I observed that I could swap from the CGA display to the VGA display by entering "mode mono".

Altering the motherboard's video switches from the CGA setting to the EGA/VGA setting changed nothing.

Swapping out the first compatible VGA card for the second compatible VGA card changed nothing.

So, the above indicates that you will need to remove the IBM CGA card before adding the compatible VGA card, and alter the motherboard's video switches from the CGA setting to the EGA/VGA setting.
 
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andromeda92 said:
I didn't think there was an ATI video card that could drive the IBM 5155 internal screen. So the IBM 5155 screen supports EGA in monochrome
Click to expand...

Not exactly. The 5155’s screen is just a plain NTSC frequency composite monitor, normally not compatible with anything but CGA. ATI just happened to specialize in, with their “Wonder” series of cards, adding a proprietary ASIC allowing their cards to display altered versions of video modes that normally required one type of monitor on a different type. How usable this feature really was varied, but the EGA Wonder’s composite support does an okay job at displaying at least the “game-centric” EGA modes in grayscale.
 
I just tested it on a 486 dx2 66 and it works well, the bios is 2.15
I haven't had time to do it on the IBM 5155 yet,
I also found the bus setting jumper 8 bit or 16 bit .
The documentation is here
OAK OTI 037C 2.15
 
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modem7 said:
But a problem I saw is that the VGA display showed programs in monochrome (no colour). There may be other problems as well.
Click to expand...

From the description of the behavior you’re seeing I would hazard a guess that the BIOS of your particular VGA card is detecting there’s the CGA card present and essentially configuring itself as if it were an EGA card connected to a 5151 TTL Mono monitor. An EGA card in that mode only supports MDA-style text and a single 640x350 video mode, but because it limits itself to that it doesn’t conflict with CGA’s memory or IO addressing and can thereby coexist.

Obviously there would be a hardware memory conflict in the B8000 area if the VGA card enabled color text or CGA compatible graphics modes, so it’s good that the card is smart enough to suss this out. I wonder how common this is, though.
 
What is the chip EPROM for this card ?
The VGA BIOS is split to two EPROM mays be is two 27128 or 27127 ?
 
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