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386 mobo base 64K error

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Mike Chambers

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Sep 2, 2006
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i have a motherboard here, model Everex EV1830D

it has a 386 DX-20 chip on it. when i try to boot it, i get three short beeps. it has an AMI BIOS chip, so i found that it means "Base 64K RAM failure"

i've never done anything like replacing chips on a mobo before. i was under the impression that these motherboards used the installed SIMMs even for base RAM. i tried different sticks of memory, no help. so maybe i'm wrong on that. can any experienced person here maybe help me out a little? i'd love to get this thing running.

thanks! :)
 
Mike Chambers said:
i have a motherboard here, model Everex EV1830D

it has a 386 DX-20 chip on it. when i try to boot it, i get three short beeps. it has an AMI BIOS chip, so i found that it means "Base 64K RAM failure"

i've never done anything like replacing chips on a mobo before. i was under the impression that these motherboards used the installed SIMMs even for base RAM. i tried different sticks of memory, no help. so maybe i'm wrong on that. can any experienced person here maybe help me out a little? i'd love to get this thing running.

thanks! :)
Click to expand...

What kind of memory sticks have you tried?
What kind of BIOS does it have?
 
Mike Chambers said:
i get three short beeps. it has an AMI BIOS chip, so i found that it means "Base 64K RAM failure"
Click to expand...
One Internet site indicates that 3 beeps from an AMI BIOS means "Base 64K or CMOS RAM failure, fatal", and so a bad CMOS chip is another possibility.
Another possibility is that the 3 beeps are being issued by a BIOS on an expansion card, eg. VGA card.

Mike Chambers said:
i was under the impression that these motherboards used the installed SIMMs even for base RAM
Click to expand...
Yes, that was the norm.
 
Amigaz said:
What kind of memory sticks have you tried?
What kind of BIOS does it have?
Click to expand...

i tried using four 1 MB sticks from another 386 board i have. (i made sure to set the memory jumpers/DIP switches accordingly for the new chips) the BIOS chips are labeled "1830D REV-G2-34 (91)"
 
modem7 said:
One Internet site indicates that 3 beeps from an AMI BIOS means "Base 64K or CMOS RAM failure, fatal", and so a bad CMOS chip is another possibility.
Another possibility is that the 3 beeps are being issued by a BIOS on an expansion card, eg. VGA card.


Yes, that was the norm.
Click to expand...

i have a different 386 board that appears to be dead. i wonder if the CMOS chip from that one would be transferrable to this board. unfortunately, i'm not sure exactly which chip is the CMOS though. (i'm much more of a software guy than a hardware guy lol)

if i took a high-res pic of the board, do you think you would be able to tell?
 
Mike Chambers said:
i tried using four 1 MB sticks from another 386 board i have. (i made sure to set the memory jumpers/DIP switches accordingly for the new chips) the BIOS chips are labeled "1830D REV-G2-34 (91)"
Click to expand...

Some board only work with 9 chip simm's...my Asus 386 board is one of them
 
Druid6900 said:
And a LOT of 386 boards had problems with anything other than 3 chip SIMMs. Make sure all 4 are the same size and speed, of course.
Click to expand...

they're all the same speed, but one is a 3-chip, one's a 2-chip, and the other two are 9-chip. i unfortunately don't have enough of the same type to fill a bank up. :(

two are 1MB, and two are 4 MB.. i have the banks DIP switches/jumpers set to them all being 1 MB figuring that'd work.. guess not, but i've tried all possible combinations. they worked great mixed and matched together in my old 386 before the board went out.

i'm going to order some new RAM. it's so cheap. problem is, i can't find info on exactly what type it needs. i know it's 30-pin SIMMs of course.. i'm just wondering, parity/non-parity? 70ns? 80ns? 2/3/9-chip? i know it'll work with 1 MB chips at least. grr, damn lack of documentation.

i'm looking at this. http://memoryx.net/1mbx981.html

they have plenty of other kinds. i wonder what the safest bet would be?? i'd be happy with 4 MB on the thing.
 
Last edited:
SIMMs have to be, pretty much, identical sets. 30-pin have to be the same chip count, speed, parity set-up and capacity size for the set of 4.

72 pin SIMMs have a little more leeway. Chip count and "sidedness" doesn't seem to be an issue, as long as the capacity size and speed is the same for each pair.

Since, in my experience, a much greater percentage of 386 boards balk at the 9-chip SIMMs, you're probably better off getting the 3-chip ones. As for speed, well the maximum RAM speed is the reciprocal of the CPU clock speed.

There are boards that don't care what you throw into them as long as they are matched.

YMMV
 
modem7 said:
One Internet site indicates that 3 beeps from an AMI BIOS means "Base 64K or CMOS RAM failure, fatal", and so a bad CMOS chip is another possibility. Another possibility is that the 3 beeps are being issued by a BIOS on an expansion card, eg. VGA card.
Click to expand...
If you remove all expansion cards, and you still hear the 3 beeps, then you know it is the motherboard generating the beeps.
If you then remove all memory SIMMs, and you still hear the 3 beeps, I would think that that is a good sign that the problem is "base 64K".

Amigaz said:
Some board only work with 9 chip simm's...my Asus 386 board is one of them
Click to expand...
Looking at the board description on Total Hardware, the 256KB SIMMs are described as "256K x 9" and the 1MB SIMMs are described as "1M x 9", and so maybe this is one of those boards.

Druid6900 said:
And a LOT of 386 boards had problems with anything other than 3 chip SIMMs. Make sure all 4 are the same size and speed, of course.
Click to expand...
Yes, all SIMMs in a bank (repeat, bank) must be the same type. And that is reflected in the document on Total Hardware.

Mike Chambers said:
I'm going to order some new RAM. it's so cheap. problem is, i can't find info on exactly what type it needs. i know it's 30-pin SIMMs of course.. i'm just wondering, parity/non-parity? 70ns? 80ns? 2/3/9-chip? i know it'll work with 1 MB chips at least. grr, damn lack of documentation.
Click to expand...
Parity is a definate. The "9" in 9 chip SIMMs represents 8 data bits plus 1 parity. The "3" in 3 chip SIMMs represents two 4-bit data chips plus 1 parity. But per above, Total Hardware is suggesting 9 chip SIMMs. As for speed, 80nS will be good for a 386-20.


Mike Chambers said:
i'm looking at this. http://memoryx.net/1mbx981.html
Click to expand...
Looks good.


Looking again at the EV1830D description on Total Hardware, the following jumper setting is not clear to me.


Code: 
                       USER CONFIGURABLE SETTINGS
                Function                     Jumper          Position

  »   Memory type select 256K SIMMs            W1            Pins 2 & 3

      Memory type select 1MB SIMMs             W2            Pins 1 & 2
                                                              closed


Is this a typo, ie. only one jumper is involved to switch between 256K SIMMs and 1M SIMMs ???

If two jumpers are involved, I think it must be:
256K SIMMs --> W1 = 2/3 , W2 = 2/3
1M SIMMs ----> W1 = 1/2 , W2 = 1/2
 
Wow this is bring back RAM headaches.
My general rule of thumb with picky motherboards is to try each pair one at a time. If I find one type (chip count and/or speed) that works I stick with that adding one pair at a time. I also run memtest86 when they are all in to make sure they are working right.
If the test finds an error I take them all out and add one pair at a time and run a memtest to see when the error appears.

I have had 2 motherboards I can think of that were very picky, but once I found a happy combo everything was good.
To make my life easy I always test each pair of ram alone in some computer to make sure it is still working. 2 loops in memtest86 is good enough for me when I do this.

Have fun :)
Joe
 
ok it actually doesn't boot all the way lol. it tests the RAM and half the time stops at 512 KB and the rest of the time stops at 1024 KB.

i'm going to order 8 sticks of 3-chip 80ns 1 MB SIMMs and just fill both banks with identical RAM. the motherboard is probably fine.
 
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