If the BIOS lets you, tighten your ram timings. I had the same issue and I am amazed on how much it helped

sunaiac wrote:

Your VLB system is too slow.
Write back seems to be disabled too.

How does that quote go... "Fool me once, shame on you. Fool me twice, shame on me."

This board's seller said he included an AMD DX4-100.. but that appears to NOT be the case here. I should've checked right away but I assumed all was well since it did report the speed correctly. GRRRRRR...

Well... what do we have here... 😕

GAH! 😒

Let's put the CORRECT processor in...

CPUID is recognized by SpeedSys now:

...but the L1 cache still shows as "Write Through"

So I have the correct processor in place and the L1 & L2 caches are set to write-back mode in the bios. I'm wondering if there is perhaps a jumper config on the board itself that sets the L1 cache to write-back mode as well. Anyone have any experience with this combination of board and processor?

Once I get WB enabled I'll run through the benchmarks... again.. PFFT. 😒

Welcome to the wonderful world of 486 🤣

Anyone have any experience with this combination of board and processor?

You need to set the jumpers correctly for that CPU. Check your manual (which I belive you own). If not it is available on the ASUS webpage: support.asus.com/download.aspx?SLanguag ... 2G%20(GX4)

Don't short J21 2-3, (as that will enable WT), follow the picture which is 3-4!

You need the 1996 or 1999 BIOS to get the Am5x86-P75 to run. For that you need an EEPROM burner as the BIOS can't be flashed (I had a very good member here help me out to burn it)

Why can't it be flashed??

BIOS file : SV2G0401.AWD
BIOS Ver. : 0401 (#401A0-0401)
Related Mainboard : VL/I-486SV2G(X4) Rev. 2.0 or above
Related Chipset : SiS 85C471 chipset

Description :

1. To support the following CPUs :
a.) AMD 486DX4 (SV8B) : with green & L1 cache write-back.
b.) Intel 486DX4 (&EW) : with green & L1 cache write-back.
c.) Cyrix 486DX4 : with green & L1 cache write-back.
d.) Cyrix 5x86 (M1sc) : with Pentium code inside.
e.) AMD 486DX4 (NV8T) : non-green & L1 cache write-through.

The new CPUs jumper setting as the follow :

A) Cyrix 486DX4 P/O
Cyrix 5x86 (M1sc)

JP16 : 1-2,5-6 (short)
JP17 : 1-2,5-6 (short)
JP18 : 1-2 (short)
JP19 : 1-2,3-4,5-6 (short)
JP20 : (none)
JP21 : (none)
JP22 : 1-2 (short)

B) AMD 486DX4 (SV8B)
Intel 486DX4 (&EW)

JP16 : 1-2,4-5 (short)
JP17 : 1-2,5-6 (short)
JP18 : 1-2 (short)
JP19 : 1-2,3-4,5-6 (short)
JP20 : (none)
JP21 : 3-4 (short)
JP22 : 1-2,4-5 (short)

C) Cyrix 486DX4

JP16 : 2-3,5-6 (short)
JP17 : 2-3,5-6 (short)
JP18 : 2-3 (short)
JP19 : 2-3 (short)
JP20 : 2-3 (short)
JP21 : 1-2 (short)
JP22 : 1-2 (short)

D) AMD 486DX4 (NV8T)
AMD 486DXL4

JP16 : 1-2,5-6 (short)
JP17 : 4-5 (short)
JP18 : 4-5 (short)
JP19 : (none)
JP20 : 4-5 (short)
JP21 : (2-3 short : 2x CLK, 2-3 open : 3x CLK)
JP22 : 1-2, 4-5 (short)

Artex wrote:

Why can't it be flashed??

Old technology. Flashable BIOS'es started showing up around 1994-1995.

From ASUS's old webpage from 1996

VL/I-486SV2G/GO/GOX4/GX4
Note: VL/I-486SV2 or older MB and VL/I-486SV2G/GX4/GO/GOX4 are using the M27C512 EPROM it needs the EPROM writer to do the BIOS upgrade programming.

Argh - the plot thickens...

Interesting!! I appreciate the info. I guess I've been spoiled doing all these BIOS flashes over the years. 😜

vetz wrote:

(I had a very good member here help me out to burn it)

I had no idea that physically programming these chips was the only way to do this back in the day. So people basically had to buy these chip programmers themselves if they wanted an updated BIOS that supported the latest processors, etc?

Would you mind shedding some light on this process? Do I need to buy a new chip, program the 0402 AWD flash file to it, pull the old chip out and replace it with the freshly flashed chip? Sorry, kind of a newb at this kinda thing. I did some digging though and it seems that while these chips are cheap, the burners/programmers are not.

Now that I have the PCI-based Biostar 486 up and running, I'd really like to get this VLB system running at it's full potential as well - with WB caching enabled.

Thanks!

Artex wrote:

I had no idea that physically programming these chips was the only way to do this back in the day. So people basically had to buy these chip programmers themselves if they wanted an updated BIOS that supported the latest processors, etc?

Would you mind shedding some light on this process? Do I need to buy a new chip, program the 0402 AWD flash file to it, pull the old chip out and replace it with the freshly flashed chip? Sorry, kind of a newb at this kinda thing. I did some digging though and it seems that while these chips are cheap, the burners/programmers are not.

Back in the days you could program them yourself, or buy the chip from ASUS or a reseller (I think I've seen a price of $9.99 going around).

You can either buy a new chip or use an old reprogrammable one. The chips are cheap on Ebay, so no need to use a 20 year old chip IMO. You use a EPROM (USB or RS232) burner and add the file onto the chip. Then you replace the BIOS chip on your board with the new one.

The burners are not very cheap, so getting someone to help you out for the price of a beer or two and you paying shipping might be good idea 😀

vetz wrote:

The burners are not very cheap, so getting someone to help you out for the price of a beer or two and you paying shipping might be good idea 😀

I'm a big fan of this idea. Any fellow Vogoneers out there willing to help a brother out?

😀

My plan is to replace an old 28-Pin EPROM with a flashable 32-Pin EEPROM, once I receive it:
Atmel AT29C512-12P = 512 kilobit = 64 kiloByte
I will hotflash it with a i440BX board, using uniflash software. Then install it in the 486.

I have got a STG G540 programmer, what exactly you want to burn, Artex?

bristlehog wrote:

I have got a STG G540 programmer, what exactly you want to burn, Artex?

Hey Bristlehog - It sounds like I need to purchase a M27C512 EPROM Chip and have it programmed with the latest BIOS for my Asus VL/I-486SV2GX4 Rev. 2.1 board. I believe it's the 0402 bios.

Artex wrote:

bristlehog wrote:

I have got a STG G540 programmer, what exactly you want to burn, Artex?

Hey Bristlehog - It sounds like I need to purchase a M27C512 EPROM Chip and have it programmed with the latest BIOS for my Asus VL/I-486SV2GX4 Rev. 2.1 board. I believe it's the 0402 bios.

You should do the 0402.001 BIOS, which is from 1999. It fixes the Y2K bug. Also don't you have two of these boards?

vetz wrote:

Artex wrote:

bristlehog wrote:

I have got a STG G540 programmer, what exactly you want to burn, Artex?

Hey Bristlehog - It sounds like I need to purchase a M27C512 EPROM Chip and have it programmed with the latest BIOS for my Asus VL/I-486SV2GX4 Rev. 2.1 board. I believe it's the 0402 bios.

You should do the 0402.001 BIOS, which is from 1999. It fixes the Y2K bug. Also don't you have two of these boards?

I do have two of these boards - a rev 2.0 and a rev 2.1. I haven't checked the rev 2.0 board's BIOS yet, but I would imagine that one is outdated too. In that case, I guess I would need two of these chips flashed with the most recent BIOS in case I end up running a Cyrix 5x86 chip in the other..

I think this is the one..
http://www.driversguru.com/driverdetail/92738 … 2g4021.zip.html

Driver Name: sv2g4021.zip
Driver Version: 0402.001
Release Date: 1999-12-21
File Size: 45,31 (KBytes)

Artex wrote:

I think this is the one.. http://www.driversguru.com/driverdetail/92738 … 2g4021.zip.html […]
Show full quote

I think this is the one..
http://www.driversguru.com/driverdetail/92738 … 2g4021.zip.html

Driver Name: sv2g4021.zip
Driver Version: 0402.001
Release Date: 1999-12-21
File Size: 45,31 (KBytes)

Looks like the same which is available on asus.com

The G540 programmer is able to flash M27C512 chip. However, I am unskilled at this, only flashed few GAL chips with the help of carlostex. It seems that M27C512 can only be written once, this creates a risk to screw things up if I do something wrong. Isn't there any option to replace M27C512 by something that is read compatible with it but rewriteable?

bristlehog wrote:

The G540 programmer is able to flash M27C512 chip. However, I am unskilled at this, only flashed few GAL chips with the help of carlostex. It seems that M27C512 can only be written once, this creates a risk to screw things up if I do something wrong. Isn't there any option to replace M27C512 by something that is read compatible with it but rewriteable?

You can erase an EPROM if you have an UV EPROM eraser.

Maybe an EEPROM could work instead though, The Electrically Erasable Programmable Read-Only Memory (EEPROM) was developed to provide an electrical erase function and has now mostly displaced ultraviolet-erased parts. I'm not an expert though.

The G540 is easy to use!

Just got to know the brand and model of the flash chip. I flashed my Biostar that way.

It tells you through a diagram how to insert the chip. It also comes with a little adapter for newer flash chips (the little square ones).

vetz wrote:

Maybe an EEPROM could work instead though, The Electrically Erasable Programmable Read-Only Memory (EEPROM) was developed to provide an electrical erase function and has now mostly displaced ultraviolet-erased parts. I'm not an expert though.

That is what I was saying. There are even 28 pin EEPROMS designed to be a drop in replacement for old EPROMS.