VOGONS


First post, by douglar

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I know that a single VLB card build will almost always have higher signal tolerance and less chance of a show stopping incompatibility than a 2 VLB card build, but is there a general rule of thumb for which VLB slot to use first to get the best chance at a stable single VLB card build ?

For example, I have a shuttle hot 419 mobo with 3 VLB slots and I want to use a single VLB card. Is it a good idea to:

* Use the slot closest to the CPU first to get the shortest paths between card and cpu ?
-- or --
* Use the farthest slot, to reduce echos from the end of the traces?

Are there any other things besides number of VLB cards and bus speed that can affect VLB stability?
Can the total number of RAM modules affect stability?
Do 5v CPUs do better than 3.3V CPUs?

(other than dust & dirt of course, which almost always seems to be an issue when working with a 25+ year old board that had a rough life)

Reply 1 of 42, by TheMobRules

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If you keep the bus frequency at <= 33MHz then you shouldn't have issues getting 2 or 3 VLB cards running at the same time without the need for adding wait states or delays.

For 40MHz YMMV, sometimes you can use it without adding wait states, sometimes you can't, depends on the cards. But keep in mind VLB motherboards usually have jumpers for these settings (see JP33, 34, 55 and 69 of your board).

50MHz bus I wouldn't recommend for 24/7 stability, but feel free to try. Only certain cards work properly with this configuration.

Also, I don't think CPU voltage how close the slot is to the CPU is going to affect much (or anything) in this case.

Reply 2 of 42, by stalk3r

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As said above...I have the same motherboard and I found only one card that runs pretty stable at 50 Mhz , the rest is 40 or less. It does not matter which VLB slot you use as long as there is only one card. Only 2 cards VLB setups have some restrictions on which slot is used. If stability is the only goal , then keep BIOS timings fail-safe and use 33 MHz FSB. Set the Wait state jumper to 1 on the card (provided it has one)...that's pretty much it.

Reply 4 of 42, by Nemo1985

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I have a Biostar MB-1433/50UIV-a rev 3.1
Jumper 36 is MCA3 VESA BUS Slot Select:
1-2 Closed Synchronous Mode
2-3 Closed Asynchronous Mode

I tried both settings but it changes nothing about the performance, what is it then?
Also at 40 mhz it's stable with 1 wait state but if I use 50mhz the pc gives me black screen, I use 15ns cache, could it be a proble with l2 cache?
I'm using vlb video card (ARK Logic ARK1000VL VLB 2mb) and ide vlb controller (Multi I/O Card VLMIO V1.6 PIC).
I tried to take off the vlb controller to check if it boots at 50mhz but it doesn't.
Any suggestion?

Thanks

Reply 5 of 42, by stalk3r

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Nemo1985 wrote on 2020-02-11, 19:48:

Also at 40 mhz it's stable with 1 wait state but if I use 50mhz the pc gives me black screen, I use 15ns cache, could it be a proble with l2 cache?
I'm using vlb video card (ARK Logic ARK1000VL VLB 2mb) and ide vlb controller (Multi I/O Card VLMIO V1.6 PIC).
I tried to take off the vlb controller to check if it boots at 50mhz but it doesn't.

I have such a card, but it did not boot for me either at 50 MHz. It wasn't even stable at 40 if I remember correctly. At least it's a quite fast card.
You should try different cards and settings, trial and error. I tried at least 5-6 different cards before I found one which runs stable at 50 MHz: Chips & Technologies F64300 VLB vga question

Reply 6 of 42, by Nemo1985

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Thank you for the advice, actually is the only VLB card I have (those aren't easy to find nowadays), but I will get a Cirrus logic card soon...
I'm using it on a full umc board (chipset+cpu) so to get decent performance I will probably need to overclock it to 50mhz

Reply 7 of 42, by stalk3r

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Nemo1985 wrote on 2020-02-11, 20:41:

Thank you for the advice, actually is the only VLB card I have (those aren't easy to find nowadays), but I will get a Cirrus logic card soon...
I'm using it on a full umc board (chipset+cpu) so to get decent performance I will probably need to overclock it to 50mhz

VLB cards do not really like 50 MHz bus speed in general, neither do CPUs from this era for that matter.. It does not mean that you won't find a combination that works, it's just not so trivial.

Reply 8 of 42, by appiah4

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TheMobRules wrote on 2020-02-10, 17:35:
If you keep the bus frequency at <= 33MHz then you shouldn't have issues getting 2 or 3 VLB cards running at the same time witho […]
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If you keep the bus frequency at <= 33MHz then you shouldn't have issues getting 2 or 3 VLB cards running at the same time without the need for adding wait states or delays.

For 40MHz YMMV, sometimes you can use it without adding wait states, sometimes you can't, depends on the cards. But keep in mind VLB motherboards usually have jumpers for these settings (see JP33, 34, 55 and 69 of your board).

50MHz bus I wouldn't recommend for 24/7 stability, but feel free to try. Only certain cards work properly with this configuration.

Also, I don't think CPU voltage how close the slot is to the CPU is going to affect much (or anything) in this case.

While this is the common advice passed around on Vogons it's not true, I've had boards (looking at you ECS 480-UL1) where even two VLB cards (VGA + Multi I/O) failed to work 100% on a 33MHz bus regardless of wait states. Some VLB Multi I/O cards are very anal about how they use the VLB apparently.

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Reply 9 of 42, by douglar

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appiah4 wrote on 2020-02-12, 08:47:

While this is the common advice passed around on Vogons it's not true, I've had boards (looking at you ECS 480-UL1) where even two VLB cards (VGA + Multi I/O) failed to work 100% on a 33MHz bus regardless of wait states. Some VLB Multi I/O cards are very anal about how they use the VLB apparently.

I've got a Trident VLB card that just won't work in protected mode if I add a VLB IDE card. 33mhz bus. Tried two different IDE cards. When I switch to a 16 bit card, it's all good.

Reply 10 of 42, by douglar

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I have a Cirrus Logic 5429 VLB card that was an interesting test case. It wasn't completely stable in the slot closest to the CPU or the slot farthest from the CPU, but has seemed stable in the middle slot. Could just be a matter of cleaner contacts in that slot, or some other peculiarity unique to this board. I was not using any other VLB cards in the build.

Reply 11 of 42, by barleyguy

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This is a curious topic for me, because VLB was never very stable, even when it was brand new. It was a stopgap between ISA and PCI, only lasted a couple of years, and none of the cards for it were very good. So a thread asking about a stable VLB setup is very odd.

That said, the 33 Mhz clock doubled chips like the 486 DX2/66 seemed to work the best. They had a separate 33 Mhz FSB, so matched the speed of the VESA bus perfectly.

EDIT: Note that I'm new here. I feel like I'm walking up to the campfire of the natives and wondering about the funny dance that they're doing. Maybe I'll eventually figure out why people do what they do.

Reply 12 of 42, by Doornkaat

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barleyguy wrote on 2020-02-26, 04:29:

This is a curious topic for me, because VLB was never very stable, even when it was brand new. It was a stopgap between ISA and PCI, only lasted a couple of years, and none of the cards for it were very good. So a thread asking about a stable VLB setup is very odd.

I can not relate to this opinion at all. The bus is not as reliable as PCI but it's not bad. I have had very little trouble with VLB setups as long as I kept it somewhat conservative. There are lots and lots of stable VLB builds. What's odd about wanting one yourself? And why would you say there are no good VLB cards?

barleyguy wrote on 2020-02-26, 04:29:

That said, the 33 Mhz clock doubled chips like the 486 DX2/66 seemed to work the best. They had a separate 33 Mhz FSB, so matched the speed of the VESA bus perfectly.

Do you mean an external 33MHz bus? The 66MHz DX2 is simply a popular choice because it offered a good price/performance ratio at the high times of VLB. I don't see a reason why a clock tripled 100MHz i486DX4 would work less reliable.

Reply 13 of 42, by TheMobRules

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barleyguy wrote on 2020-02-26, 04:29:

VLB was never very stable

I disagree, at 33/40MHz bus speed, a decent VLB motherboard+card(s) is in most cases very stable. The problem is that this early to mid-90's era of hardware was kind of a "wild west" scenario, with shady nameless manufacturers and dodgy stuff like fake cache.

barleyguy wrote on 2020-02-26, 04:29:

none of the cards for it were very good

Also disagree here. At least for video cards, the high end ones offer as good performance as a 486 allows and are roughly equivalent to their PCI counterparts, while even the crappier ones (Trident for example) still offer a noticeable improvement over ISA (except for specific cases such as those Weitek 9000s in DOS).

barleyguy wrote on 2020-02-26, 04:29:

They had a separate 33 Mhz FSB, so matched the speed of the VESA bus perfectly.

The DX4-100 and 5x86-133 also ran with an external bus speed of 33MHz, but the VESA local bus frequency is not restricted to that value, being a local bus means that it connects directly to the CPU and runs at the same (external) bus speed, be it 25, 33, 40 or 50MHz in the case of the 486 VLB. Higher speeds (>= 40MHz) do have more electrical restrictions when it comes to timings and number of cards on the bus though.

In general, while it was indeed a very short-lived bus, from around 1993 until widespread PCI adoption in 1995-96 it was a solid option. Sure, there were Pentiums with PCI around the same time, but until the prices dropped these were just not an option for the common user.

Reply 14 of 42, by barleyguy

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Doornkaat wrote on 2020-02-26, 05:18:
I can not relate to this opinion at all. The bus is not as reliable as PCI but it's not bad. I have had very little trouble with […]
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barleyguy wrote on 2020-02-26, 04:29:

This is a curious topic for me, because VLB was never very stable, even when it was brand new. It was a stopgap between ISA and PCI, only lasted a couple of years, and none of the cards for it were very good. So a thread asking about a stable VLB setup is very odd.

I can not relate to this opinion at all. The bus is not as reliable as PCI but it's not bad. I have had very little trouble with VLB setups as long as I kept it somewhat conservative. There are lots and lots of stable VLB builds. What's odd about wanting one yourself? And why would you say there are no good VLB cards?

barleyguy wrote on 2020-02-26, 04:29:

That said, the 33 Mhz clock doubled chips like the 486 DX2/66 seemed to work the best. They had a separate 33 Mhz FSB, so matched the speed of the VESA bus perfectly.

Do you mean an external 33MHz bus? The 66MHz DX2 is simply a popular choice because it offered a good price/performance ratio at the high times of VLB. I don't see a reason why a clock tripled 100MHz i486DX4 would work less reliable.

My perspective on this is that I built computers for a living when this stuff was cutting edge, and had to sell it to customers and support it. I never felt VLB was stable enough to bet on. Maybe I just never found the perfect combination of parts, but IMO both ISA and PCI were way more stable than VLB was. (As was EISA for that matter, but it was most common in really expensive workstations so wasn't for mere mortals.)

From the perspective of building a machine for yourself and tinkering with it until it does what you want, I guess VLB could be considered "stable enough". But that was never my experience with it when I had to build it as a product for other people.

BTW, there's no reason a clock tripled 100 mhz chip would be any less stable. Didn't mean to imply that. I simply meant processors with a 33 Mhz bus, and preferably faster than 33 Mhz.

As far as my comment about wondering why people do what they do: I just joined here very recently, and personally I would never choose to build a VLB system. I'd either go slightly older than that, or slightly newer. Specifically because of the reasons I stated about not wanting to mess around with finding a stable combination of components for VLB. So I wonder why someone would choose to build something from this era.

EDIT (additional thoughts): Maybe I should just shut up for a while and try to figure this place out. Or maybe I just don't fit in here, and will never figure it out. Is this a matter of wanting to build a comprehensive list of every PC ever? Or do people have nostalgia for certain eras and want to relive that nostalgia? I'm just really trying to understand the motivation.

I don't have nostalgia for any particular era of computing really. My very first computer as a kid was a TRS-80 model one with 16k of RAM and a cassette player. And I've used or built virtually everything since then. When I look towards building a retro machine, I would tend to choose something I see as "good" in both the hardware realm and the OS realm. I'm genuinely not criticizing, but trying to understand what's up around here. Also, sorry for the topic hijack.

Reply 15 of 42, by appiah4

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People arguing against the 'fact' that VLB was not a very stable bus probably need to test out more boards than the few they got lucky with. Shit gets incredibly annoying as soon as you try to add a VLB Multi-I/O to the system or try a 40MHz or above FSB.

Retronautics: A digital gallery of my retro computers, hardware and projects.

Reply 16 of 42, by brostenen

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appiah4 wrote on 2020-02-26, 12:05:

People arguing against the 'fact' that VLB was not a very stable bus probably need to test out more boards than the few they got lucky with. Shit gets incredibly annoying as soon as you try to add a VLB Multi-I/O to the system or try a 40MHz or above FSB.

I think that I have been very lucky with VLB so far. This might be because I never had any low quality boards. I have only had brands such as FIC, Edom and A-Open. Edom ran 2xVLB cards at 33mhz in 1995 to 1998 at my place, and the other brands are what I have had since around 2015 or something. They both have run 2xVLB cards at 40mhz.

I think you are spot on, that low quality stuff will run unstable.

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Reply 17 of 42, by ynari

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There's no doubt that VLB was a stopgap bus that wasn't very good, but I have to say my 486 box was bomb proof, the Multi I/O was quite fast, and the Cirrus Logic 5426 compatible and reasonably quick. I did use a 5V 33MHz 486 with it at the time though. When I rebuild it, it's going to have a DX2-66 clocked down to 40MHz (as it's a bit too hot and quick otherwise), so we'll see what it's like..

Reply 18 of 42, by Intel486dx33

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See my post on my 486dx4-100 VLB build.
In particular see the Intel Overdrive CPU I used and read the Gigabyte motherboard manual.
That manual has allot of good info on it as to what IRQ, DMA, and settings to use which apply to most motherboards
I use it always as a reference on all my 386/486 builds.

Link:
486 Multimedia dream build ( 1993/94 ).

Reply 19 of 42, by TheMobRules

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appiah4 wrote on 2020-02-26, 12:05:

People arguing against the 'fact' that VLB was not a very stable bus probably need to test out more boards than the few they got lucky with. Shit gets incredibly annoying as soon as you try to add a VLB Multi-I/O to the system or try a 40MHz or above FSB.

The VLB boards I own are made by ASUS, MSI, Gigabyte, Acer/AOpen and Biostar. All of those work stable at 40MHz with 2 VLB cards (video and I/O) after setting the appropriate jumpers. Granted, my experience is mostly based on SiS, UMC and Bioteq chipsets, so I can't say anything about VIA or Opti chipsets for example, but I tend to avoid those as they're generally slower (I also have a nameless Unichip based board but it sucks regardless of whether I'm using the VLB slots or not).

barleyguy wrote on 2020-02-26, 05:33:

EDIT (additional thoughts): Maybe I should just shut up for a while and try to figure this place out. Or maybe I just don't fit in here, and will never figure it out. Is this a matter of wanting to build a comprehensive list of every PC ever? Or do people have nostalgia for certain eras and want to relive that nostalgia? I'm just really trying to understand the motivation.

I guess not everyone here is interested in the same thing, some may be looking for the most practical build for retro-gaming, others might just like tinkering with old hardware (because of nostalgia or curiosity), and some maybe a bit of both. Also, most sections in the forum don't even deal with retro hardware at all (VOGONS is Very Old Games On New Systems after all...). So I don't think there's any need to "fit in". You probably also had a motivation of your own to join in, right?