I thought you didn't like VLB stuff? 😉

This one is by far the best imho if we're talking pure ISA/VLB mobo's:

http://cgi.ebay.com/VL-I-486SV2GX4-Rev-2-0-48 … =item2ea5ba119e

But there's other ISA/VLB mobo's that are of better quality not listed in this "madman's" ebay shop

Hehe! Yes you're right, I'm not the world's biggest fan of VLB, but I feel that I ought to incorporate a good VLB 486 in to my retro tests. You know a lot about VLB 486s - please can you recommend some good models not featured in this guy's high priced listings? (Sorry if this has been asked before.)

I reckon the ISA486SV2, but I've only owned three boards, and one of them was a PC CHIPS. =/

retro games 100 wrote:

Hehe! Yes you're right, I'm not the world's biggest fan of VLB, but I feel that I ought to incorporate a good VLB 486 in to my retro tests. You know a lot about VLB 486s - please can you recommend some good models not featured in this guy's high priced listings? (Sorry if this has been asked before.)

hehe, some people and myself consider "real" 486 mobo's have VLB slots 😉

If you're looking for a well built, high spec VLB mobo you'll have to go the Eisa route...can't come up with alot of model names right now but my fave is the Everex EV18210 (full at size) and the Eisa model on the pic below (names escapes me)

This is the EV18210

EISA is for servers? I guess that's why they are built to be the best.

Just going back to the VL/I-486SV2GX4 for a moment. I understand there are many revisions for it, including a 2.1. I don't know if there is a higher revision. But is 2.0 considered to the best revision? Thanks a lot.

retro games 100 wrote:

EISA is for servers? I guess that's why they are built to be the best.

Just going back to the VL/I-486SV2GX4 for a moment. I understand there are many revisions for it, including a 2.1. I don't know if there is a higher revision. But is 2.0 considered to the best revision? Thanks a lot.

Not just servers, for workstations too so it's a mobo built to last and it can handle high loads without being a bottleneck

Higher revision is always better.

Another great thing about the Eisa mobo's is that they often have socketed Dallas DSxxxxx trc/cmos etc chips 😀

Rev 2.0 and 2.1 of the VL/I-486SV2GX4 only differ in one detail. 2.1 provides voltages between 3.3V and 5V (3.45V, 3.6V, 4.0V) intended for Cyrix processors.
I have both revisions, the 2.1 is inside my Retro-PC.
Revisions prior 2.0 have no proper support for Writeback-enhanced CPUs.
The latest Bios supports Am5x86, Cx5x86 and also hard drives up to 8 GB.

Thanks very much for the info people! Also, please can someone recommend a VLB VGA card, to go with this mobo? I am interested in: (1st) good image quality, (2nd) good DOS performance. I don't require good Windows 3/9x performance, because I would like to use DOS only for this VLB machine. Thanks a lot! 😀

Tseng Labs ET4000 W32 seems to be "The card to have"

Yep ET4000 W32p is what I'm running in my 486 at the moment. (note the p, there is a W32, a W32i and a W32p, the p is the one to go for). I was running an S3 805 before that, and to be honest I don't notice the difference... I get the same score in 3dbench with both cards. I think I also tried a Cirrus Logic GD5429 and it was only very slightly behind.
At higher resolutions though the differences between the cards become more apparent, although at 640x480 we are still talking less than 10fps in PCPBENCH, even with the ET4000 W32p . Games with SVGA mode like Tie Fighter absolutely chug along on my 486 regardless of video card.

If you're only going to be using it at standard VGA resolution I'd have a look at the 3dbench benchmark thread because that gives you a good idea of what cards are better than others. If you want to use it at 640x480 you might be better off going to a pentium. Having said that, I've only tried a Pentium Overdrive and a DX4-100, if you get a 5x86 and overclock it you might actually get pretty respectable performance in SVGA out of it 😀

Thanks a lot for the advice people! If Amigaz recommends one, and BastlerMike's got one in his retro PC, then getting a 486SV2GX4 myself means a very good buy! 😀 And I'll keep my eyes open for a ET4000 W32p too. In the meantime, my piggy bank's a bit low on "retro credits", but I bought this VLB VGA card seen below. It's made by STB, and it's got Powergraph VL-24 written on the BIOS.

I would be very interested in OC'ing the 486SV2GX4 VLB board, using an AMD P75. I would like to see if it's capable of doing 4x multi @ 50 MHz bus speed = 200 MHz CPU clock speed. Also, I noticed when I was testing a 386 mobo using a Cirrus Logic VGA ISA card, this ISA card coped the best when I increased this mobo's bus speed to high values. I wonder, when you set a VLB 486 to use a bus speed of 50 MHz, do most VLB VGA cards cope OK? I know that if you set the bus speed to 50 MHz for a 486 PCI board, bad things can happen!

STB Powergraph VLB 1MB Local Bus Video PC VGA Card P86c

The general consensus about overclocking and VLB is that it works together like oil and water. As soon as I get my PC-chips M915i board out of Russia i will be able to fully give this a proper test but until then I'm just twiddling my thumbs.

Some motherboards have an option to allow the vlb bus to run a-sync with the processor. Again this is something that going to be fun to test.

That looks like an S3 805 so it should be fine. As for overclocking VLB it was pretty notorious for having issues with fast bus speeds. That's why the 486DX50 was less popular than the DX2-50.

The VESA Local Bus is a direct extension of the 486's memory bus (or "front side bus"), hence the term "Local Bus".

As such it's quite intolerant of higher than spec clock rates.

VLB is rated to work at 50MHz if the video is integrated into the motherboard. Otherwise you can do one card at 40MHz or two cards at 33MHz. Some people have good results with two cards at 40MHz, but it depends on the quality of the cards and the motherboard.

I have the Hercules Dynamite Power (ET400032P). This card works flawlessly at 50MHz, and many others have confirmed this as well.

Thanks for the info people! The jumper settings for the Asus VLI-486SV2GX4 revision 2.0/2.1 mobo can be found here. In it, there is no mention of a CPU voltage option for 5v. It seems that you can only go up to 4V. This reminds me of the limited CPU voltage options available for another Asus 486 mobo, the PCI based PVI-486SP3 model.

However, Vogons user 5u3 explained how to bypass this limitation, by removing a pin (S4) from the AMD P75 CPU. By doing this, the voltage detection on the CPU was not activated, and the chip ran at 5V. This is what I want to do, because I'll probably need 5V going through this P75 CPU if I am to succeed in OC'ing it using a configuration of 4x multi + 50 MHz bus speed.

I'll have to wait a couple of weeks for my new old bits to arrive. I'll post back with an update then. Regarding a VLB VGA card that works @ 50 MHz - I'll just have to keep my fingers crossed that one of the very small handful of cards I have will work. Failing that, I could attempt to get everything working, but use an ISA VGA card. And if it all works, I'll try to get a VLB based ET4000. 😀

I've just received this mobo, the Asus VL/I 486SV2GX4 revision 2.1. Unfortunately, it looks like the battery leaked, because there is fur on parts of the mobo. However, it POSTS OK and seems to work. I have installed a P75, but the BIOS POST screen says that it's an AMD DX4 S, @ 120 MHz. ChkCPU seems to think that the CPU is running at 133 MHz, with a multi of 4, and a bus clock speed of 33. So, the BIOS POST message seems to be incorrect.

Also, ChkCPU thinks the L1 cache is in write-through mode. The mobo's BIOS is the initial version, and I would like to flash upgrade it. I tried Uniflash, but it would not run, because it said that it couldn't find the PCI bus.

Questions please, people: Are these jumper settings correct, especially for the P75 setting? http://www.motherboards.org/files/manuals/1/C … I-486SV2GX4.htm

Please can someone tell me what flash program I need to run, in order to flash upgrade this mobo. I was able to get the latest BETA BIOS from Asus website, by looking inside their socket 5 folder. Thanks a lot for any help! 😀

Some good news - while I am waiting for some kind person to advise me on the correct jumper settings for a write-back P75, 😀, I have got this CPU running at 200 MHz, and more importantly, Quake 1 timedemo works. Now, please understand that the BIOS settings are set to slow, and the CPU is running desperately slowly because it's in write-through mode. But at least it's a start. BTW, I'm using an S3 805 VLB card. My Quake timedemo score is about 50% worse than my best PCI 200 MHz score.

I wonder if flashing the BIOS will enable the system to fully recognise this P75 CPU, and consequently, the BIOS POST will display the correct CPU identification and speed, and also run it in Write-Back mode?