I grew up with a DTK 486. It used a very interesting "symphony" chipset. Personally I found it to be very fast and stable. My board was ISA only, but it beat the hell out of everyone else's system for memory throughput due to its page-interleave mode. I always wanted to get my hands on a VLB symphony board, but they aren't nearly as common. Symphony must have gone out of business shortly afterwards since they just completely disappeared. It's possible that their VLB boards were terrible and sunk them.

DTK used to produce their own boards and used many Symphony chipsets until about 1993 when there was a huge internal scandal. After that they mainly used OEM "gemlight" boards based on the SiS chipset, which were also pretty good (but in my opinion the PCB quality wasn't as nice as the old DTK boards). I've always been interested in these DTK PCI SiS chipset boards. I've always wanted to play with a PKM 0033S. Too bad they don't seem to have PS/2 support. There appear to be some undocumented jumpers on this board. I wonder if it supports higher FSBs than we know.

PS/2 direct support is not a must IMHO. You can buy a serial optical mouse if you can live without the wheel (I can, I am using Windows scarcely) or buy a special KVM switch that translates serial to PS/2. In this case, however, only ball mice can used (which understand both protocols, of course)

I just went to goodwill actually and found a shrinkwrapped IBM PS/2 mouse with serial adaptor. That should work for the 486, and it's just one extra mouse, no big deal. I can still switch video and keyboard with my kvm.

They had a PS/2 model 70 there too. Tempting, but I already have a 386 class machine, and I don't want to get involved in buying a bunch of MCA stuff for it. Too many damn busses.

I wouldnt ditch that broken VLB board yet.
What is the damage report on the oxidized traces, show us the damage.

As for VLB, they are more unstable, especially when using several, but they have more bandwidth than an PCI card will ever get. But most wont like 50Mhz, and with PCI you can run 50FSB easily.
Of course the later PCI cards use faster video processors than whatever a VLB card ever had, so PCI is the obvious performance winner / due to the faster vga chip choice.
But VLB is more retro and a more cool factor(if you like to gaze at it hardware wise), brown slots with long cards and true local FSB performance, ET4000 W32P i prefer to use over any PCI card in my 486, but sadly it does not like high bus speeds, but blood shows good fps with the tseng though.

And VLB was used in 386 and 486 and 586. 😀, a friend of mine actually has or had a 386DX with VLB.

VLB was intended for the 486 architecture as a local bus. The later adoptions to 386 CPUs on 386/486 combo boards* (OPTi 495slc/slx based) and Socket 4 and Socket 5 boards (OPTi Premium and OPTi Python based) were slow (really slow), no match for the VLB on a 486.

*there are some rare boards that provide decent VLB speed with a 386/486dlc cpu, though.

And no, 50MHz FSB is not easy on any PCI board unless you use a fsb/pci divider. Many controllers and network cards and quite a few graphics cards just refuse to work at this high speed. 50MHz VLB is doable, it's just not simple and needs experience and of course the right board and the right cards.
But I think that make VLB interesting. It's a challenge.. it was in 1993/1994 and it's still a challenge in 2012. I love it 😉

I've come across a couple of OPTi 495slc's recently, and although it initially seemed like a useful board with the 386 / 486 support + VLB slots, it's proved to be incompatible with a couple of my favorite VLB / ISA boards.

OPTi 495SX should have fixed most of the incompatibilities with the 495SLC. It's compatible, but as FGB said not too quick. VLB on Pentium though is not slow. I had a VLB Pentium board based on an OPTi chipset that predated premium. It was just as fast as the 486.

FGB wrote:

www.AmoRetro.de Visit my huge hardware gallery .

Why have you posted this link? Now I will have to waste hours to click through the gallery to see all the hardware. And since I know German, I will have to read all the descriptions. But seriously - nice work 😉

SiS 496/497 has a known bug; second IDE port is useless. First encountered it 15 years ago, and did not find out why the second IDE controller did not work until I tried some Linux.

of course i meant to use 50fsb and a 25mhz pci clock or such by a divider.

btw anyone knows a good muiltio ide vlb card?

I had a Promise EIDE2300 Plus back in the olden times. It has primary VLB IDE, secondary ISA IDE, floppy, and serial and parallel ports.

Someone wanted to see the damage to the dead board. The top looks OK after cleaning it up, I thought I could get away with just replacing the bios socket and chip. But when I turned it over... Well, just look at the attachment. It's mostly in the upper left corner, and more than I think I can repair.

BTW, I got my new 486 board today. I'll take some pictures when I build it, and make a new thread in System Specs.

Well the new board doesn't like my old video card. I have a spare ATI VGA Wonder, and that works so the board is OK. But with the VLB card in it, the board doesn't respond at all. Not even a beep.

The VLB card is a Diamond Stealth 64 DRAM T. There doesn't seem to be anything to configure on it. The motherboard seems to have only one jumper related to VESA function, that's the wait state and I've tried both.

That leaves me with BIOS options. Unfortunately, I don't have an external battery clip so I can't play with those. There's not much that looks relevant though. "Local Bus Ready Delay" perhaps? It seems to be enabled by default. How is this related to the wait state jumper on the board? And would misconfiguration cause a complete lack of responsiveness from the system?

did you clean the VLB-contacts? I know from first hand experience that this area is very prone to collect dirt that, although it might not be visible, makes the surface less conducting. give it a try 😀

I took your suggestion and gave it a good buffing with some deoxit and qtips. I did get a lot of black stuff on the qtips, but I got it all off and it's still not booting. I tried disabling the wait state in the bios, and disabling video bios shadowing. Also tried lowering the frequency to 25/50. Not a hint of life when the VLB card is installed.

The thing works great with the VGA Wonder though. I did have to replace the RAM. Funny, the RAM on the good board was bad, but the ram on the bad board was good. In any case it boots and I got DOS 6.22 installed on an old 6.7gig hard disk I had. Enough for tonight.

I've had compatibility problems with certain cards in my SiS VL/EISA motherboard. If I remember correctly, my Hercules Terminator 64 DRAM (also based on Trio64 like your card) really didn't like my system. And two different cards based on ET4000W32P gave me a black screen when certain soundcards were installed (one was a CS4232 based card, and several YMF719 cards). You may just have incompatible hardware.