The photo looks like it's from the 90s too but I think that's the Opti VLB/PCI Pentium chipset. PCI performance will be lacking. VLB and Pentiums don't make sense together because VLB is based on the 486 bus. This chipset is a engineering curiosity created to bait 486 upgraders who wanted to continue using their VLB cards.

For your reading enjoyment,
http://groups.google.com/groups/search?hl=en& … rch&sitesearch=

If you want one of those boards I have one in a box next to me. the only cravat is the pci and the vlb slots dont work. just the isa ones. 😜

I've kept it around jsut because of its rarity.

luckybob wrote:

If you want one of those boards I have one in a box next to me. the only cravat is the pci and the vlb slots dont work. just the isa ones. 😜

I've kept it around jsut because of its rarity.

You should nail it to a wall or something 😵

Well looks like they existed and some selled them. Check this advertisment and page after with specifications....

http://books.google.cz/books?id=Od_7AEHBZvgC& … graphic&f=false

A Pentium board with EISA and VLB? Crazy.

Dant wrote:

I was looking on Ebay recently for a 486 motherboard with VLB and PCI slots for a build I was considering when I came across this: http://www.ebay.com/itm/Fastest-VLB-Motherboa … =item1e67384119

After I balked at the ludicrous price they were asking, I recognized that this is a Socket 5 Pentium board... with VLB slots. To me that is a complete impossibility, I always thought VLB was deeply entrenched in the architecture of the 486. So, how is this possible, and how well would it work?

Some Nexgen nx586 motherboards have VL-Bus slots but they don't also have PCI slots. It's either one or the other. The nx586 is weird, though, because a lot of apps see it as an insanely fast 386 (486/Pentium specific instructions are emulated) instead of as a Pentium class chip, so that might account for why VL-Bus works with them. They also have a dedicated logic chip on board (not the BIOS chip) that sits between the CPU and the buses like a traffic cop in a busy intersection so the VL-Bus slots may see what they need to see to function on the logic chip rather than the nx586 itself.

I've always wanted a VLB/EISA pentium system.

I had a ISA VL Pentium board at one point. It was somewhat of a lemon, but it was really fun to play with. I believe opti made several variations of the VL Pentium set. One of them must have been pretty decent, because it found it's way into AMI motherboards and AST systems.

I believe there may have been at least one other company that did a VL Pentium chipset. It may have been UMC or SiS.

here is a better picture of the board I have. You see its the same as the one in the auction.

I have the "evil" though of buying that $400 board, and swapping it with mine that doesn't work, and returning it. Just to put the screws to that over-pricing jackoff.

Apparently the PCI bus on Opti Premium is quite nasty.

Those aren't the ONLY problems. According to OPTi documentation on the chipset, it has a few built-in bugs that sound quite ser […]
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Those aren't the ONLY problems. According to OPTi documentation on the
chipset, it has a few built-in bugs that sound quite serious (and might
be why mine crashes so often). Back-to-back DMA transfers (whatever that
means) will cause a system crash. So will bus-mastering PCI devices.

As far as I know there is only one Chipset for the Pentium who does this task. It is the Opti Premium Chipset with a VLB to PCI […]
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As far as I know there is only one Chipset for the Pentium
who does this task. It is the Opti Premium Chipset with
a VLB to PCI Bridge, also comming from Opti.

The Premium Chipset is mainly a VLB Chipset.
It supports 2 VLB Master and one Slave.
The PCI to VLB Bridge takes one of the Master Slots and forms
4 PCI Master Slots out of this.
So you have 1 VLB Master, 1 VLB Slave and 4 PCI Master slots.

Because implemented via the VLB the PCI can only be as fast as
the VLB slot, but because there is a lot of wok to do, it is much
slower. I think actualy the PCI to VLB Bridge brings
about 10MB/sec maximum transfer-rate. But I think Opti is going
to improve this.

The VLB slots itself are not slower as on other boards. But the
PCI are. Also the other system perofomance (DRAM Cache etc.) is
the same as on other boards.
So only the PCI Slots are much slower!

But there is an other problem. I think it is the main-problem.
It is getting all the cards PCI VLB and ISA work togher.
And I get really crasy about this problem!

luckybob wrote:

I have the "evil" thought of buying that $400 board, and swapping it with mine that doesn't work, and returning it. Just to put the screws to that over-pricing jackoff.

I'd say go for it, this wiredforservice deserves it (makes me wonder what he'd take as an offer...) only problem is they'd likely notice the different color PCB and different placement of the VLB slots...

Also, these OPTI implementations are absolutely terrible if what swaaye says is true. Why would they not bother putting a proper PCI implementation in and rather just bridge an already unstable VLB slot to it?

I dunno, I've heard some bad things from people about that wiredforservice dude, there's a good chance he'll just tell you to suck it and wear the negative feedback.

DonutKing wrote:

I dunno, I've heard some bad things from people about that wiredforservice dude, there's a good chance he'll just tell you to suck it and wear the negative feedback.

This. When you sell thousands of items a year getting one or two negs isn't going to destroy your reputation. The problem is that ebay/Paypal can decide to give a refund anyway so he could end up out the merchandise and the money.

As far as I know there is an older VL Pentium chipset from opti called "Viper", and an even older one that I couldn't find a name for (the one I had, no PCI support).

There seem to be various Chipsets from Opti for Pentium and VLB

Opti Python Opti Cobra?????
http://pclinks.xtreemhost.com/chipsets_pentium.htm

I have an AMI Excalibur (afaik) with Opti 82c596/82c597. Some months ago i tried to get it to work but it was very difficult to find RAM the Board accepted and RAM-Speed was very slow. I then gave it up. Maybe this year Ill give it another try;)

The VLB Pentium board I had used the opti 82C571/82C572 chipset. It was also extremely picky about memory combinations like your board. I was never really able to find much information on the chipset in this board. It was interesting though in that it could support both 486 and Pentium CPUs. I am pretty sure that this must have been the first VL Pentium chipset from opti.

The chipset on your board is called "Opti Premium" as you can see on the chips. I believe that one was fairly common at the time. I've never used one myself though.

There is a 3rd Opti VL-Pentium chipset I am aware of called "viper". I'm not actually sure if it was ever released, but I remember reading a lot about it in the early 90s. I'm not sure if it was something that came before or after the Premium chipset.

As you said, there may be others as well.

You should keep trying with the AMI board. AMI made pretty good quality stuff, and they usually had pretty good memory throughput when configured correctly.

The "Viper" chipset (82C556) is Opti's first chipset to implement true PCI Design (c't 11/95). The VL chipset you are referring to is called "Python" (82C546) and is the 3.3V capable variant of the "Premium" (82C596) chipset (ct 12/94). However, in some references this chip is also called "Cobra" 😕
Couldn't find anything about the 82C571 though.

Apparently there are at least two versions of Viper. The older one is VLB/PCI hybrid. The pure PCI design as you mentioned, is called "Viper-M".

This is the most complete list of OPTi chips I've been able to find to date:

http://www.plasma-online.de/index.html?conten … cture/opti.html

I noticed that OPTi even had an AGP chipset. I thought they had given up in the early 90s, but it appears they soldiered on for a little while longer

Also notice there was a dual processor viper chipset. That would be pretty cool to have...

I found a few brochures for OPTi Pentium Products:

Pentium Adaptive WriteBack (82C596/597), 64-bit cache (up to 2MB), 64-bit DRAM
http://bitsavers.trailing-edge.com/pdf/opti/b … ochure_1992.pdf

Pentium uP WriteBack Cache EISA (82C693/696) cache *may* be 64-bit, DRAM is certainly 32-bit (from PCMag)
http://bitsavers.trailing-edge.com/pdf/opti/b … ochure_1993.pdf

486/Pentium WriteBack (82C571/572), 64-bit cache, 32-bit DRAM.
http://bitsavers.trailing-edge.com/pdf/opti/b … ochure_1993.pdf

There are also Pentium boards with EISA based on i430NX chipset. For example Micronics M54PE - 2x socket 5, up to Pentium 200 MHz. 😀
Compared to late socket 7 chipsets, performance of this one is terrible...but maybe still better than OPTi.

http://hw-museum.cz/view-mb.php?mbID=1