Good on you for persevering.

jdgabard wrote on 2021-01-01, 22:42:

As mentioned above that trace near the batter going from the KB Controller to near the ISA slots does look to have been eaten through by the leakage. This can be fixed by soldering a jump wire. But you need to check it to see if it is connected. If it were me, I'd probably desolder the KB Connector, KB Controller socket, and clean a little better, and inspect it a bit further. Probably wouldn't hurt to replace those either.

Are you getting any beep codes when connecting a speaker or buzzer to the speaker header?

When I start the board without memory, I get the expected 3 beeps for base 64k memory error. And, I think it was before I cleaned it again, I got 6 beeps (A20 error) when having the keyboard controller inserted, but I don't get these anymore, if I insert the keyboard controller, nothing happens.

Are the traces on the Mainboard "open", so if I touch them with my multi meter, would I be able to measure something, so are the traces that I can see conductive or is something protecting them? Do I just solder a wire over the damaged part? I hope you understand what I mean..

And I found a page with the post codes of a AMI Plus BIOS (which I think I have). http://www.bioscentral.com/postcodes/amibios.htm
There it says, that "14" is the code for 8042 controller tested, this should be the first code I won't see when I have the Keyboard BIOS not inserted, right?
As the board now isn't beeping 64k error anymore, I should at least get to "12", right? 😁

And would an old USB Keyboard work over a USB->PS2 and PS2->Din Adapter chain? the usb->ps2 part is working!

And on this point I'd like to thank all of you for answering all my questions, I am learning quite a bit about this 😁

Neolyum wrote on 2021-01-02, 12:10:

And would an old USB Keyboard work over a USB->PS2 and PS2->Din Adapter chain? the usb->ps2 part is working!

Yes, this will work perfectly. PS/2 and DIN connectors use exactly the same electrical protocol, it's just that the PS/2 connector is smaller. Some ancient keyboard expect a RESET signal on the DIN connector, which you won't get from more recent boards (I think, it was never present on PS/2), but as your USB->PS/2 converter works without that RESET pin, it just uses the four signals that are in common between the DIN keyboard connector and the PS/2 keyboard connector.

My POST Card just arrived and leaves me with much confusion.

The following error Codes occur when:
1 - No Keyboard BIOS, Graphics Card inserted: last number: 2C. Every time.
Edit: I saw the LED "IRDY" on the card flashing when booting, sometimes it was on, sometimes off. I started the board again and this time I saw the LED blinking, short bursts of maybe 3Hz and the PC speaker making noises at the same time. The debug code was something in the 40s and then switching to 51(?), the LED blinking with maybe 20Hz, the speaker making the same clicking sounds in the same frequency. As I found that quite disturbing, I turned my power off as fast as I could 😁 Next try did not repeat that.

2 - No Keyboard BIOS, no graphics card: Stranger things 😁
Sometimes no error code, 7 beeps. (General exception error (processor exception interrupt error) / Virtual mode exception error, found both in the internet)
Sometimes it goes on to 4A or 35 or 4F
Sometimes 2 very fast high beeps, then 8 lower pitched beeps with codes 31(prev 2F) and after the beeps 35 or 40(prev 3b). These beeps sound *totally* different from the 3 beeps for 64k memory error or the 6 beeps A20 error. I would describe them as sinus waves, the 3 beeps for example are much more scrambled.
My manual for the post test card says this is 1 long 8 short and means Display / Retrace test failed.

3- With Keyboard BIOS: Bootloop, I see numbers 01,02,05,06,10,13 and reset.

35 is quite often but does not exists in any table I have where 2C and 3b is also present.

After that I tried the second 386 I have, with that one I only get to 06 every time even without RAM. I think that one is dead ^^
Without a CPU in the Socket (so this should enable the soldered one) I get 05, so propably also dead.

Is this also a problem with the CPU I hope is working?
Is it a problem with the Video ROM as 2C is the Video ROM check? Edit2: it is the handover to Video ROM, not video memory, I used the wrong table as reference!

I used AMI BIOS GOLD http://www.bioscentral.com/postcodes/amibios.htm as reference, as the Code 2C only exists for that one. But my BIOS is labeled as AMI BIOS Plus which confuses me.
In the manual the debug numbers correspond to the ami bios gold.

If you want, I can make videos! 😀

Edit2: the card shows when beeping the trace error 31 2F and after that 40 3B.
3B does not exist for ami bios Gold but for AMI Bios win, and this table is printed in my manual, not bios gold, my bad. Why is my bios printing codes for an AMI BIOS win when it's a Plus BIOS?

I just had a closer look on my Graphics Card, a Trident TVGA8900D-R.
Is my Video ROM missing?? There is nothing in that socket and 27256 seems to be that chip. Also the Card never returns back to the BIOS after 2C.

Another question: Does a number on the card mean: that test is done (which I think) or this test is next?

Haha, yes this VGA will not work without ROM...

"The debug code was something in the 40s and then switching to 51(?), the LED blinking with maybe 20Hz, the speaker making the same clicking sounds in the same frequency."
... is not that bad. The sound you hear maybe the counting of the RAM. You should repeat that test.

You can press the button on your post card to show all tests that already have been passed.

Predator99 wrote on 2021-01-04, 13:21:

Haha, yes this VGA will not work without ROM... […]
Show full quote

Haha, yes this VGA will not work without ROM...

"The debug code was something in the 40s and then switching to 51(?), the LED blinking with maybe 20Hz, the speaker making the same clicking sounds in the same frequency."
... is not that bad. The sound you hear maybe the counting of the RAM. You should repeat that test.

You can press the button on your post card to show all tests that already have been passed.

wow so somebody sold me a VGA without ROM. Great. I think it would be easier to just get another VGA, isn't it?

OK, I'll try to get this again. The only thing I can do is rebooting until this happens :x

Its easy to copy that ROM with a programmer, an empty one costs maybe 1€.

Predator99 wrote on 2021-01-04, 13:36:

Its easy to copy that ROM with a programmer, an empty one costs maybe 1€.

OK I will try that! But what do I have to buy? 😁 I don't have a programmer, so I need one and I don't know what kind of chip I have to buy 🙁
Edit for question 2: Can I do the same with the keyboard bios as I believe it's broken?

If someone wants to see it, the video of a few tries of the board posting^^

https://youtu.be/GvzW3ze3J1M

What you hear at the beginning seems indeed to be the RAM being counted up. Therefore the board is more or less OK.

Did you try the Keyboard Controller from your other board? They cannot be copied.

For a copy of the VGA ROM you need i.e. a TLL866 and a W27C512.

Predator99 wrote on 2021-01-04, 15:33:

What you hear at the beginning seems indeed to be the RAM being counted up. Therefore the board is more or less OK.

Did you try the Keyboard Controller from your other board? They cannot be copied.

For a copy of the VGA ROM you need i.e. a TLL866 and a W27C512.

I do not have another board, I just bought 2 386 😒

Thanks for the info! 😀
Can I also read my BIOS with the TLL866? So I can provide the archive with my bios and its string 😀

Yes, you can also read and copy your system BIOS with it.

27c256-100

Is this a correct one?

Any 27c256 should work.
I would prefer EEPROMs, so you don't need UV eraser to reflash it. 😉 (In your link, it shows picture with a window to on the chip)

GigAHerZ wrote on 2021-01-04, 16:13:

Any 27c256 should work.
I would prefer EEPROMs, so you don't need UV eraser to reflash it. 😉 (In your link, it shows picture with a window to on the chip)

Good advice. Parallel EEPROMs have model numbers starting with 28 or 29. There are chips labelled 27c256 that do not have a window - but that does not mean you don't need to get UV light into the chip to get it erased. Instead, it means instead that this chip is not meant to be erased ever, and thus the expensive ceramic case with the quartz glass window was replaced by the cheap plastic case. These chips are properly called OTP-ROMs (one time programmable ROMs), even if they are based on EPROM technology, and thus very different form 1980s PROMs (old fuse/anti-fuse based programmable ROM chips). Some vendors use confusing names like "OTP ERPOM" (and spelling it out as "one time programmable electrically programmable read only memory"). Note how it does not say "erasable" in the spelled out version, although "EPROM" usually means "erasable programmable read only memory".

So, if you want to get a chip you can erase without an UV eraser, look at the model number (like 28c256), don't assume it's electrically erasable just because there is no window.

mkarcher wrote on 2021-01-05, 13:53:

GigAHerZ wrote on 2021-01-04, 16:13:

Any 27c256 should work.
I would prefer EEPROMs, so you don't need UV eraser to reflash it. 😉 (In your link, it shows picture with a window to on the chip)

Good advice. Parallel EEPROMs have model numbers starting with 28 or 29. There are chips labelled 27c256 that do not have a window - but that does not mean you don't need to get UV light into the chip to get it erased. Instead, it means instead that this chip is not meant to be erased ever, and thus the expensive ceramic case with the quartz glass window was replaced by the cheap plastic case. These chips are properly called OTP-ROMs (one time programmable ROMs), even if they are based on EPROM technology, and thus very different form 1980s PROMs (old fuse/anti-fuse based programmable ROM chips). Some vendors use confusing names like "OTP ERPOM" (and spelling it out as "one time programmable electrically programmable read only memory"). Note how it does not say "erasable" in the spelled out version, although "EPROM" usually means "erasable programmable read only memory".

So, if you want to get a chip you can erase without an UV eraser, look at the model number (like 28c256), don't assume it's electrically erasable just because there is no window.

28cxxx and others can have different pinout compared to 27cxxx.
I have lots of 27c512, which are EEPROMs. I only assume, there are 256 variants available as well.

EDIT: Quick search in aliexpress showed, there are such chips available.

The Trident TVGA8900D-R has an integrated BIOS ROM. The socket is purely vestigial, or meant for BIOS ROM updates. http://www.vgamuseum.info/index.php/component … ent-tvga8900d-r
If it didn't have a BIOS, you wouldn't be getting anything at all from the video, no sync or anything, not even a blinking cursor or colored screen. If the motherboard was running 'normally' and you tried plugging a BIOS-less VGA card in, it'd beep angrily at you. The fact that you get a colored screen or blinking cursor indicates that the board sees the VGA BIOS and is able to initialize the card to some degree before something else brings everything to a halt. If that card is not displaying anything useful when plugged into a known working motherboard, check the jumper settings on the card.

If the board can't talk to the keyboard controller it will act quite dead, or misbehave in really weird ways. Check the keyboard controller IC and its socket on your board. It's not worth trying to clean or fix old crusty sockets, you can find brand new, dual-wipe DIP-40 sockets online really cheap.
Some boards like to get particular with the keyboard controller they use too, Phoenix and DTK BIOS fitted boards can be notorious for this, though occasionally you'll come across the odd AMI BIOS board that won't boot with anything other than the keyboard controller it came with.

Eep386 wrote on 2021-01-05, 16:33:

The fact that you get a colored screen or blinking cursor indicates that the board sees the VGA BIOS and is able to initialize the card to some degree before something else brings everything to a halt.

Thats indeed a good point. Totally new to me that there cards with integrated BIOS and I have seen many...