VOGONS


First post, by opiate

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I'm building my 386 PC, everything is going great, except for my graphics card. There is no color, only monochrome display.

I know it is not driver related, because in BIOS there is no colour either, so it must be hardware, other cards works fine in color (tested on Trident TVGA9000C for example).

I am wondering - is it possible that my graphics card is broken in a way that it only display in monochrome?

Model: Tseng Labs ET4000AX

There are two jumpers: JP1 and JP2, first one is probably IRQ, second - i have no idea, changing it doesn't help.

Any ideas?

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Reply 1 of 22, by derSammler

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You can cut the trace going to pin 12 of the VGA connector (doesn't matter where). That's what is used to switch the card into b/w mode. Modern monitors are using it for DDC instead, but anything apart from "not connected" will force the card to display b/w.

http://retro-net.de/blog.html

Reply 2 of 22, by opiate

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derSammler wrote:

You can cut the trace going to pin 12 of the VGA connector (doesn't matter where). That's what is used to switch the card into b/w mode. Modern monitors are using it for DDC instead, but anything apart from "not connected" will force the card to display b/w.

Before i will put my knife to the card i just want to make sure - i need to cut connection between pin 12 and pin 4?

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Reply 3 of 22, by Jepael

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Edit:

You can modify the card to be compatible with modern monitors.

You can modify modern monitors to be compatible with your card.

But it will most likely be easier to just modify an unused VGA cable between card and monitor to make them compatible with each other.

So, you don't need to modify the card and personally would modify or suggest modifying it as it seems to be working and in mint condition.

Last edited by Jepael on 2017-05-01, 19:25. Edited 1 time in total.

Reply 4 of 22, by derSammler

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Jepael wrote:

Hack an extra VGA cable instead.

Yes, that's probably better. Did that as well, just remember that DDC will no longer work with such a cable.

http://retro-net.de/blog.html

Reply 5 of 22, by opiate

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Weird... so i've modded the cable, the pin 12 is out. Now there is no signal at all 😐 On old cable everything forks fine [fine means 'no color']

BTW: my LCD is not that new, it's Samsung SM 510N, 4:3 monitor

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Reply 6 of 22, by dondiego

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The card detects the monitor as monochrome, there's no need to do anything. The trident utility to set color mode manually (smonitor c) works with all/most isa cards.

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Reply 7 of 22, by derSammler

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opiate wrote:

Weird... so i've modded the cable, the pin 12 is out. Now there is no signal at all 😐

You removed pin 14 (v-sync), not pin 12. 😦

http://retro-net.de/blog.html

Reply 8 of 22, by opiate

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derSammler wrote:
opiate wrote:

Weird... so i've modded the cable, the pin 12 is out. Now there is no signal at all 😐

You removed pin 14 (v-sync), not pin 12. 😦

OK, that was stupid 😀 I'm watching Hobbit (for the first time) with my left eye and with my right im screwing with the cables. Will try next cable, both eyes on the cable this time 😀

Reply 9 of 22, by opiate

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dondiego wrote:

The card detects the monitor as monochrome, there's no need to do anything. The trident utility to set color mode manually (smonitor c) works with all/most isa cards.

Can you give me exact name for this utility?

Reply 10 of 22, by Jepael

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And I should have been more clear how to mod the cable - My intention was to just cut open the outer plastic of the cable so that you can access all the wires inside the cable, and then cut a wire instead of connector pin. That way you could later on connect the wire again if it was the wrong wire. There's no need to remove pins as that's not reversible..

I think that cable is useless now. Oh and by the way, for future reference, the pins have small numbers next to them in the blue plastic to identify the pin number. Almost visible in the photo as well, but they are blurry.

Reply 11 of 22, by opiate

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Weird 2.0

This time right pin was removed, there is still no color in BIOS and Dos Navigator BUT when i run Doom, color is back. WTF? Same with Windows 3.11 - the boot screen is in color, but Windows itself is black and white. Did fresh install, format c, etc. No change. What is wrong with this card? People say that this is one of the best ISA graphics, Trident (TVGA9000C) is less problematic from my experience.

Reply 12 of 22, by dondiego

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It's smonitor.exe inside tvgautil.zip from old drivers. May be there's a tseng utility for that.
The problem affects most isa cards with more modern monitors since those pins were reused later for power management.

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Reply 13 of 22, by opiate

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Closer and closer 😀

That smonitor app is great! Added it to autoexec, so now all DOS apps are in color, including DOS Navigator.

Still the BIOS is monochrome only and for some reason Scandisk (?)

Reply 14 of 22, by konc

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Can you try the card in another PC and see if you get color there with the same cable+monitor? That should rule out some possibilities.
Also check if the motherboard has a mono/color jumper, some surprisingly do but not all cards are affected by it.
Finally a (very-very) long shot: I once had a 386 with an on-board VGA which was having the exact same behavior with specific cards and an ET4000AX was one of them. Never found out why though.

Reply 15 of 22, by opiate

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As soon as i clear space for other pc stuff i will test card in other motherboards.

The mobo in fact have jumpers for color/monochrome mode, but changing it makes no difference.

Well - the combination of pin removal and smonitor app gives satisfying results, so subject closed, thanks for the help guys!

Reply 16 of 22, by Pierre32

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Excuse the bump, but I was just about to start a thread for this, and then happened to find the solution here. The exact same scenario: New 386 build, ET4000AX, and a monitor only displaying in monochrome. The monitor is a Compaq 1024:

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Weirdly enough I have a "newer" (but still pretty old obviously) Dell 1024x768 LCD, and it was displaying colour just fine. Anyway, SMONITOR.EXE sorted me out. I found TVGAUTIL.ZIP on this FTP. Still leaves me with a monochrome BIOS, but I can't complain. Thanks all.

Reply 17 of 22, by waterbeesje

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Just to be sure:
My 386 DX-40 has a jumper on the motherboard to set colour or monochrome. This has nothing to do with the graphics cards or bios but will set a signal to the graphics card to enter b/w mode or not. Could you check if yours has one just to be sure?

Also if the card displays bios in colour in another machine right away, it is probably not related to the card itself.
Maybe the Trident will force itself into colour mode regardless of your motherboard setup?
Has the Trident got a jumper to set b/w or colour mode?

Stuck at 10MHz...

Reply 18 of 22, by Pierre32

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Yep, my motherboard (Asus ISA-386C) has such a jumper. It's labelled MONO/CGA, but the data sheet actually says position 1 is EGA/VGA/MONO, and position 2 is CGA. In any case, this had no effect on the behaviour for me.

The card (which is Tseng, not Trident) has a solitary jumper on it labelled D/E. Not sure what it's for, and swapping it didn't change the behaviour.

I'm not able to test the card in another machine right now, but will be interested to try that when I can.

Reply 19 of 22, by root42

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Pierre32 wrote on Today, 11:03:

Yep, my motherboard (Asus ISA-386C) has such a jumper. It's labelled MONO/CGA, but the data sheet actually says position 1 is EGA/VGA/MONO, and position 2 is CGA. In any case, this had no effect on the behaviour for me.

The card (which is Tseng, not Trident) has a solitary jumper on it labelled D/E. Not sure what it's for, and swapping it didn't change the behaviour.

I'm not able to test the card in another machine right now, but will be interested to try that when I can.

Those jumpers mostly determine which memory address the video card is supposed to appear at: 0xB800 for color cards and 0xB000 for mono MDA cards. Maybe also if a BIOS extension was to be expected (EGA/VGA). I am wondering though why your board puts mono and EGA/VGA into one basket...?

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