Hit and miss, caveat emptor.

VLB is directly tied to the cpu's frontside bus speed, and becomes unstable outside the sweetspot of 33mhz. On some cards, they can handle being driven at 25 or 50, but the spec expects 33mhz.

Few 486 systems were pci, and those that were, has a very primitive north and south bridges, and may not fully implement the spec. (Eg, some pci cards may not work)

so if I had a 66mhz or od 100, will it be stable?

If the FSB is 33mhz, yes.

Very well... I already am considering to buy one from a private source and the board will also have about 256k of L2 cache on top. plus the VLB video card will be MUCH faster than my Zenith Z Select 100 XE will be with it's integrated isa video bus.

You can consider dual booting Win95B or Win95C / DOS.
I'd recommend to use either VLB or PCI boards, but due to performance reasons no combined ones.
With PCI you probably won't need voltage regulator. PCI graphics cards are rather cheaper. But do NOT use a PCI SCSI card. PCI boards most likely will support write back L1 cache method. PCI BIOSes most likely will support hard disks > 504 MB but won't go beyond 8.4 GB. PCI is 5 Volt only, and do not expect (far) too new graphics cards to run in that slots. Many PCI boards have a way to connect a PS/2 mouse.
With VLB you also may go to 40 MHz. Most systems tolerate it without adding extra wait states. Most VLB boards support 5 Volt CPU only. Write back L1 just is supported on some boards. Most VLB BIOSes will cap hard disks at 504 MB. You most likely will be stuck to a serial (RS/232) mouse.

AvocadoLongfall wrote on 2023-09-01, 03:59:

Very well... I already am considering to buy one from a private source and the board will also have about 256k of L2 cache on top. plus the VLB video card will be MUCH faster than my Zenith Z Select 100 XE will be with it's integrated isa video bus.

Do not install too much RAM when you have 256 kB of L2 cache.
Using L2 cache in write back mode you have a cacheable area of 32 MB.

I will likely at this point have perhaps about 16-24 megs of ram.

Disruptor wrote on 2023-09-01, 04:07:

PCI BIOSes most likely will support hard disks > 504 MB but won't go beyond 8.4 GB.

I am currently in the process of wrapping up a 486/PCI system with Zida 4DPS V2.11. Although bios detects the 1083MB HDD values correctly, only 503MB is usable, so those limits may apply on these boards. My board has the latest bios, at least stable release.

I’m going to slap XTIDE boot rom to the network card to deal with the issue.

It's just me, but i'd rather use ezbios with the memory area relocation driver, than have to deal with having a nic or other source of adaper rom squatting in the umb region.

wierd_w wrote on 2023-09-01, 05:57:

It's just me, but i'd rather use ezbios with the memory area relocation driver, than have to deal with having a nic or other source of adaper rom squatting in the umb region.

I’ve installed NIC on every DOS system I have, they are simply a must for me. So the ability to install a boot rom on one is pretty much just extra. I have one IBM PS/2 with similar setup and I haven’t found that 8KB on UMB to be a problem. You just need to set it correctly to memory, so you can get at least 64KB contiguous UMB block.

I find this soution very elegant, but that is just me ofc.

You dont want Win95 on 486. It does load and run, but is painful to use and majority of Win95 software was written with Pentium speeds in mind. Sure you can build OD 100MHz 32MBram PCI 486, but at that point you just build a slow Socket 5 system.
VLB vs ISA doesnt matter for Win95 all that much, what matters is the video chip used and its level of 2D hardware acceleration of Windows API. ATI, Matrox, S3 will be fine, ET4000/Cirrus Logic even VLB will be much worse.

One reason I prefer VLB over PCI is that unless you use the PCI motherboard's on-board IDE ports, your other option is to use something with its own boot rom. So make certain you get a motherboard with a decent IDE controller (not UMC) that gives good thoroughput with its driver. ISA/VLB systems work differently in this regard.

In fact, I'll be switching back to VLB because of this. Not that there's anything wrong, it's working fine with the PCI IDE controller, but I don't like the extra boot screen of the controller detecting the HDD. It's "too new" for a 486.

I am also considering possibly obtaining a Trident TGUI9400 for my system. I have heard that it may be faster than an 805 S3 and has GUI acceleration too. The Trident is a VLB card mind you.

I'd argue in favor of a different card for vlb. The pci tridents are pretty good, but I recall pain and suffering from my vlb one. Ymmv.

wierd_w wrote on 2023-09-02, 06:00:

I'd argue in favor of a different card for vlb. The pci tridents are pretty good, but I recall pain and suffering from my vlb one. Ymmv.

As long as the Trident is the 9440AGi it is perfectly competitive according to mpe's comparison: https://dependency-injection.com/wp-content/u … 01-1024x736.png (and full article here: https://dependency-injection.com/vlb-vga-group-test/)

Really for DOS gaming the only VLB card that needs to be avoided is the Viper VLB (Weitek P9000) because it's an ISA VGA card and VLB Windows accelerator card on one card.

This is what I got
https://www.ebay.com/itm/134528434298?hash=it … ABk9SR9rbvsXKYg

wierd_w wrote on 2023-09-02, 06:00:

I'd argue in favor of a different card for vlb. The pci tridents are pretty good, but I recall pain and suffering from my vlb one. Ymmv.

Which vlb card would you recommend?

I did not use many vlb cards; i was young and poor back then.

I just vaguely recall pain with mine, concerning it and my vlb ide controller. I can't recall the specifics. I vaguely recall the card constantly trying to creep out of the slot.

PCI with my first pentium was much nicer, that I do recall.

I see. Is there an all rounder vlb card that works fine with windows and dos?