1. No idea, but you may have issues running PCI outside of 33mhz. Some peripherals/bridges are more tolerant, some are not.

2. As far as I know, 4k refresh modules are the ones to watch out for. They appear at half their rated capacity in incompatible boards.

3. I've dealt very little with EDO/FP. Can't speak to it.

4. BANG

EZFlyer wrote:

1. No idea, but you may have issues running PCI outside of 33mhz. Some peripherals/bridges are more tolerant, some are not. […]
Show full quote

1. No idea, but you may have issues running PCI outside of 33mhz. Some peripherals/bridges are more tolerant, some are not.

2. As far as I know, 4k refresh modules are the ones to watch out for. They appear at half their rated capacity in incompatible boards.

3. I've dealt very little with EDO/FP. Can't speak to it.

4. BANG

🤣 thanks

Although, to be accurate, the bang is already "the universe" banging. I was talking about its origin (which, by the way, is also the origin of time, so, it can't even be said to have occurred "before" as there's no time before time, therefore it's not located at all in time... good luck bro! 🤣 )

1) Obviously I would opt for a UMC8881/8886 or SiS496/497 board - e.g. the LuckyStar LS486E, GA-486 AMS, Shuttle HOT433, etc..
The LuckyStar's PCI bus is slower than that of the UMC based boards but can be clocked higher - 60mhz(suspect an auto multiplier or meek timings) and 50 for latter - only cards that can run at this speed are Matrox & NVidia 128/TNT. The LS486E managed 44 mb video speed in speedsys at 60mhz PCI bus.

2) for sure only the Lucky Star LS486E Rev C2 or D(C1 and F do not). Not sure about the HOT433 but mine supported it.

3) EDO is faster in theory and some benchmarks. The real advantage is having access to more modules which may run at higher speeds. There are some 50ns ones, but not all of them are better than some good 60ns ones. Same goes for srams.

1) Another board besides the 8433UUD you already mentioned in the other thread which can run the PCI Bus at 40MHz just fine in my experience given that the PCI card in use can take the increased speed is the LS486e.

2) Can't say for sure.

3) EDO is a later tech and faster in theory, however on a 486 it makes little to no difference. Some claim FPM to be more stable e.g. Feiopa however I just run a single 32MB EDO module in all 486 PCI boards which support that and never had any issues. FPM is more period correct for sure.

4) Stephen P. Morse

I have an Intel Classic PCI Expandable Desktop aka Ninja, which is able to support 40 and 50MHz FSB (and PCI) via a small modification to the PLL and has support for EDO. I also developed an utility to vastly enhance memory performance of it too. I'm not sure if the i420EX supports L1 writeback but there is an option in the chipset settings and my program enables it.
Look for SETARIES here : http://www.tmeeco.eu/TKAYBSC

EDO allows to start a new cycle while old cycle still outputs data. This allows for tighter timings and greater performance as there's no more need for a small wait between access cycles. It is also why boards that don't have support for EDO fail to boot with EDO installed.

IS their a bios setting to look out for, that makes the pci bus run at 40mhz?

I imagine that's mostly jumper business rather than something software controlled.

amadeus777999 wrote:

1) Obviously I would opt for a UMC8881/8886 or SiS496/497 board - e.g. the LuckyStar LS486E, GA-486 AMS, Shuttle HOT433, etc.. […]
Show full quote

1) Obviously I would opt for a UMC8881/8886 or SiS496/497 board - e.g. the LuckyStar LS486E, GA-486 AMS, Shuttle HOT433, etc..
The LuckyStar's PCI bus is slower than that of the UMC based boards but can be clocked higher - 60mhz(suspect an auto multiplier or meek timings) and 50 for latter - only cards that can run at this speed are Matrox & NVidia 128/TNT. The LS486E managed 44 mb video speed in speedsys at 60mhz PCI bus.

2) for sure only the Lucky Star LS486E Rev C2 or D(C1 and F do not). Not sure about the HOT433 but mine supported it.

3) EDO is faster in theory and some benchmarks. The real advantage is having access to more modules which may run at higher speeds. There are some 50ns ones, but not all of them are better than some good 60ns ones. Same goes for srams.

Wow bro you know motherboards and tiny details on video cards!!!

Eleanor1967 wrote:

1) Another board besides the 8433UUD you already mentioned in the other thread which can run the PCI Bus at 40MHz just fine in m […]
Show full quote

1) Another board besides the 8433UUD you already mentioned in the other thread which can run the PCI Bus at 40MHz just fine in my experience given that the PCI card in use can take the increased speed is the LS486e.

2) Can't say for sure.

3) EDO is a later tech and faster in theory, however on a 486 it makes little to no difference. Some claim FPM to be more stable e.g. Feiopa however I just run a single 32MB EDO module in all 486 PCI boards which support that and never had any issues. FPM is more period correct for sure.

4) Stephen P. Morse

Wow!
🤣 for the n. 4 I didn't know who that was!!

Tiido wrote:

I have an Intel Classic PCI Expandable Desktop aka Ninja, which is able to support 40 and 50MHz FSB (and PCI) via a small modification to the PLL and has support for EDO. I also developed an utility to vastly enhance memory performance of it too. I'm not sure if the i420EX supports L1 writeback but there is an option in the chipset settings and my program enables it.
Look for SETARIES here : http://www.tmeeco.eu/TKAYBSC

EDO allows to start a new cycle while old cycle still outputs data. This allows for tighter timings and greater performance as there's no more need for a small wait between access cycles. It is also why boards that don't have support for EDO fail to boot with EDO installed.

How can you even modify the PLL and what is PLL????
I'll check your link out...

Wow guys, I have no words!!! THANK YOU!

MB-8433UUD runs the PCI at 40 MHz fine. However, you won't be able to use the onboard IDE at 40 MHz. I suggest an add-on IDE or SCSI card.

Why do you want EDO RAM? There isn't any speed benefit of using it on 486 boards. The wait states are what limit your speed. Best bet is to use FPM 50 or 60 ns. The greater the cache, the higher the FSB, the more RAM you have, the more sensitive the system will be to timings, especially with single-banked cache and EDO (vs. FPM) RAM. To play it safe, stick with FPM and double-banked cache. If using FSB at 40 MHz, I suggest starting with 256K double-banked cache. Get everything stable at 256K + your RAM of interest + 40 MHz before venturing out further.

Most motherboards will run with a 40 MHz PCI bus just fine, minus the onboard IDE. Issues will emerge on border line safe cache and RAM wait states. If you have 256K, 40 MHz, and 32 MB running just fine with all minimal wait states using a Cyrix 5x86-120, for example, don't think that you will be able to keep all these zero wait states if you increase the cache to 1024K and 128 MB of RAM. This issue is especially apparent if you are using a 40 MHz FSB and/or with EDO RAM.

EDIT: I have an insanely long test matrix I have created to this effect using the MB-8433UUD, but haven't gotten around to putting it into an electronic document.

feipoa wrote:

MB-8433UUD runs the PCI at 40 MHz fine. However, you won't be able to use the onboard IDE at 40 MHz. I suggest an add-on IDE o […]
Show full quote

MB-8433UUD runs the PCI at 40 MHz fine. However, you won't be able to use the onboard IDE at 40 MHz. I suggest an add-on IDE or SCSI card.

Why do you want EDO RAM? There isn't any speed benefit of using it on 486 boards. The wait states are what limit your speed. Best bet is to use FPM 50 or 60 ns. The greater the cache, the higher the FSB, the more RAM you have, the more sensitive the system will be to timings, especially with single-banked cache and EDO (vs. FPM) RAM. To play it safe, stick with FPM and double-banked cache. If using FSB at 40 MHz, I suggest starting with 256K double-banked cache. Get everything stable at 256K + your RAM of interest + 40 MHz before venturing out further.

Most motherboards will run with a 40 MHz PCI bus just fine, minus the onboard IDE. Issues will emerge on border line safe cache and RAM wait states. If you have 256K, 40 MHz, and 32 MB running just fine with all minimal wait states using a Cyrix 5x86-120, for example, don't think that you will be able to keep all these zero wait states if you increase the cache to 1024K and 128 MB of RAM. This issue is especially apparent if you are using a 40 MHz FSB and/or with EDO RAM.

EDIT: I have an insanely long test matrix I have created to this effect using the MB-8433UUD, but haven't gotten around to putting it into an electronic document.

I can vouch for this as well.
In all my tests, while I did not witness stability issues with EDO vs FPM, I also did not push my bus speeds beyond 40MHz, and also saw absoutely no speed benefits from EDO over FPM. Not even 0.1fps in Quake or DOOM.
I'll trust feipoa's conclusions. I went with TI 60ns FPM 32MB modules.

aries-mu wrote:

How can you even modify the PLL and what is PLL????
I'll check your link out...

PLL is the chip on most motherboards that creates all the clocks that everything else uses. On that particular motherboard I have there's only room for 25 and 33MHz FSB, but with a small modification you can also get 40 and 50MHz FSB. Unfortunately PCI and FSB speeds cannot differ on it so when running things at 50MHz you have PCI that is this fast too and you might have hard time finding cards that work. In my setup I have an ALI based RAID card for HDD that can do 66MHz PCI and works fine and an ATI 3D Rage II that seems to have no problems with 50MHz either, but one Intel 100Mbit NIC gets unstable and only works sometimes on 50MHz while it works always on 40MHz. I also noticed that ambient temperature started playing a big role also, it has been over 30ºC inside the past week and I actually had to increase wait states on memory to make the machine stable while earlier with sane temperatures it had no issue running with tightest timings.

I have also noticed the temperature effect. It usually manifests itself when you put the case on and let it run for a hour or more. I've also noticed that with tight timings, the system might run well in the winter, but not in the summer. Adding a wait state corrects for the fault.

[quote="feipoa"]MB-8433UUD runs the PCI at 40 MHz fine. However, you won't be able to use the onboard IDE at 40 MHz. I suggest an add-on IDE or SCSI card.

Why do you want EDO RAM? There isn't any speed benefit of using it on 486 boards. The wait states are what limit your speed. Best bet is to use FPM 50 or 60 ns. The greater the cache, the higher the FSB, the more RAM you have, the more sensitive the system will be to timings, especially with single-banked cache and EDO (vs. FPM) RAM. To play it safe, stick with FPM and double-banked cache. If using FSB at 40 MHz, I suggest starting with 256K double-banked cache. Get everything stable at 256K + your RAM of interest + 40 MHz before venturing out further.

Most motherboards will run with a 40 MHz PCI bus just fine, minus the onboard IDE. Issues will emerge on border line safe cache and RAM wait states. If you have 256K, 40 MHz, and 32 MB running just fine with all minimal wait states using a Cyrix 5x86-120, for example, don't think that you will be able to keep all these zero wait states if you increase the cache to 1024K and 128 MB of RAM. This issue is especially apparent if you are using a 40 MHz FSB and/or with EDO RAM.

EDIT: I have an insanely long test matrix I have created to this effect using the MB-8433UUD, but haven't gotten around to putting it into an electronic document.[/quote]

Thanks so much feipoa!

• I do not have an MB-8433UUD, I'm making this on paper, then, once the specs are finalized, little by little, I'll start sourcing the parts, compatibly with my finances.
• Wow, onboard IDE controllers don't work at 40 MHz? On all motherboards?
• What's "double-banked" cache?
• What keywords would you use on like eBay to search double-banked cache?
• Oh I don't "want" EDO RAM, I just thought (for what I remembered) it was faster. If FPM is better, than FPM it is! How would you Google or eBay FPM 50 ns ram, I mean with what keywords? Is there any brand/chip name that can facilitate the search?

[quote="tpowell.ca"]
I can vouch for this as well.
In all my tests, while I did not witness stability issues with EDO vs FPM, I also did not push my bus speeds beyond 40MHz, and also saw absoutely no speed benefits from EDO over FPM. Not even 0.1fps in Quake or DOOM.
I'll trust feipoa's conclusions. I went with TI 60ns FPM 32MB modules.[/quote]

Thanks so much topwell.ca!
• What is "TI" when you wrote TI 60ns FPM 32MB modules? Texas Instruments? What keywords would you use on eBay?

[quote="Tiido"]
PLL is the chip on most motherboards that creates all the clocks that everything else uses. On that particular motherboard I have there's only room for 25 and 33MHz FSB, but with a small modification you can also get 40 and 50MHz FSB. Unfortunately PCI and FSB speeds cannot differ on it so when running things at 50MHz you have PCI that is this fast too and you might have hard time finding cards that work. In my setup I have an ALI based RAID card for HDD that can do 66MHz PCI and works fine and an ATI 3D Rage II that seems to have no problems with 50MHz either, but one Intel 100Mbit NIC gets unstable and only works sometimes on 50MHz while it works always on 40MHz. I also noticed that ambient temperature started playing a big role also, it has been over 30ºC inside the past week and I actually had to increase wait states on memory to make the machine stable while earlier with sane temperatures it had no issue running with tightest timings.[/quote]

Interesting, thanks!
• How exactly do you perform those "small modifications"? I wouldn't even know where to start... a bootable floppy? Under MS-DOS?
• Can I modify the PLL in ANY computer? Even on those super-sealed untouchable stone-sculpted branded Compaq 486s?
• Say you wanted to use a relatively modern ATI 3D Rage II or an S3 Virge or Trio 2 PCI also under MS-DOS and old games and apps, say Sim City 2000, Win for workgroup 3.11, etc. Would they be backward-compatible? What card would you select in these games/apps setups since they won't have those names in their lists that would work just fine?

Wow guys, you know your feces around this stuff! Will you mind if I burst questions out a little more? Just a little: 🤣 😅

• What's a great PCI IDE controller which also supports Ultra DMA 33 and 66 and a 40 MHz PCI bus?
• How do I change these bloody timings? In the BIOS Setup, right?
• I noticed L2 cache chips do not clearly state their "size" in KB on their body, just a bunch of gibberish and numbers. If I find a piece of cache or a motherboard with pictures of its cache on eBay let's say, how do I exactly know the size in KB of the cache?
• Anybody got a 486-compatible PCI motherboard that works fine with bus at 40 MHz for sale at a reasonable price?
• Write-back, burst, pipeline-burst, double-banked (as opposed to single-banked I suppose),... 😕 what is the best fastest L2 motherboard cache for an advanced 486 computer?
• Those black rectangular cache chips: are they compatible with all 486 motherboards? Or does every motherboard want its own cache chips? (I totally hope not! I cannot get into a computer store in 2018 and ask for a given 486 motherboard cache chips 🤣)
• Is it possible to put a 486 on a Pentium motherboard? If no, is there any socket adapter/module/regulator to do so?
• Guys, you mention buses at 50 and 60 MHz regularly, but we're talking about 486 motherboards, not Pentium's:
    ○ Top VLB video cards (1994-1995ish, but backwards compatible with DOS time games) that can work stable long-term on a 50 MHz bus?
    ○ Top VLB SCSI cards, at least UW or higher (totally compatible and bootable in MS-DOS 6.22 and Windows for Workgroup 3.11) that can work stable long-term on a 50 MHz bus?
    ○ Top VLB EIDE cards that support UDMA 33 and 66 that can work stable long-term on a 50 MHz bus?
• On the other hand, going PCI @40 MHz bus:
    ○ Top PCI video cards (1994-1995ish, but backwards compatible with DOS time games) that can work stable long-term on a 40 MHz bus?
    ○ Top PCI SCSI cards, at least UW or higher (totally compatible and bootable in MS-DOS 6.22 and Windows for Workgroup 3.11) that can work stable long-term on a 40 MHz bus?
    ○ Top PCI EIDE cards that support UDMA 33 and 66 that can work stable long-term on a 40 MHz bus?
• Motherboard! If you were me, what motherboards would you choose for:
    ○ 50 MHz tweakable VLB, 486 motherboards, FPM compatible, super L2 cache (whatever the best cache is based on your answer to the above question) compatible, with 4 RAM slots?
    ○ 40 MHz settable PCI, 486 motherboards, FPM compatible, super L2 cache (whatever the best cache is based on your answer to the above question) compatible, with 4 RAM slots?
• RAM (whatever type): Parity or non-Parity????

Thank you all SOOOO MUCH!!!

I modified the post above ↑

The modification is done on hardware level. Typical PLL chip has configuration pins that go to some jumpers that then set the speed. In case of the Intel board there's only two settings possible out of 8 that the PLL can do so I added another jumper to make 4 of the 8 settings available. 25, 33, 40 and 50MHz, others are very slow speeds like 4, 8 and 16MHz which aren't useful.
One will need soldering skills and preferably know how to handle a multimeter and trace out where things go, it seems you wouldn't be capable of performing those modifications without learning a whole lot more about the matter.
Here's a photo of what I did on my board : http://www.tmeeco.eu/BitShit/PCschit/NinjaPLL.jpg
I was lucky and there were spots for two resistors, of which one was populated. I then removed that one and soldered a pin header on top that can be jumpered and so now I have extra speed settings at my disposal.

In theory such modifications are possible on all motherboards, other question is if the settings one can add are useful or even work on the particular board. I have one other 486 board that needs no such mods, you chan choose any of the clocks the PLL can output, but the board is stable only at 33MHz and lower, it will go unstable at 40MHz and won't boot at all at 50MHz.

Tiido wrote:

The modification is done on hardware level. Typical PLL chip has configuration pins that go to some jumpers that then set the sp […]
Show full quote

The modification is done on hardware level. Typical PLL chip has configuration pins that go to some jumpers that then set the speed. In case of the Intel board there's only two settings possible out of 8 that the PLL can do so I added another jumper to make 4 of the 8 settings available. 25, 33, 40 and 50MHz, others are very slow speeds like 4, 8 and 16MHz which aren't useful.
One will need soldering skills and preferably know how to handle a multimeter and trace out where things go, it seems you wouldn't be capable of performing those modifications without learning a whole lot more about the matter.
Here's a photo of what I did on my board : http://www.tmeeco.eu/BitShit/PCschit/NinjaPLL.jpg
I was lucky and there were spots for two resistors, of which one was populated. I then removed that one and soldered a pin header on top that can be jumpered and so now I have extra speed settings at my disposal.

In theory such modifications are possible on all motherboards, other question is if the settings one can add are useful or even work on the particular board. I have one other 486 board that needs no such mods, you chan choose any of the clocks the PLL can output, but the board is stable only at 33MHz and lower, it will go unstable at 40MHz and won't boot at all at 50MHz.

waaaat? 😳 🤣

Ok the only soldering I did is:
• Watch 2 Youtube videos on soldering
• Bought a learning kit with a little board and all the little components to build and solder: initially it didn't work, the solderings of the on/off switch and of one of the 2 red flashing lights were loose, I fixed them, and it worked perfectly
• Ready to go: I unsoldered the 3V lithium CMOS battery and soldered an external enclosure for 2xAA batteries

That's all, but tracing, figuring out that trace goes where and the multimeter thing, I have no idea.

I guess in my case it would be better to source a motherboard that already has the 40 MHz setting and is stable at that speed, including the PCI, correct?

aries-mu wrote:

4) What's the origin of the universe?

Thanks!

PS: a joke is not meant for real, therefore I hope it's not an off-topic thing 😉

aries-mu wrote:

EZFlyer wrote:

4. BANG

🤣 thanks

Although, to be accurate, the bang is already "the universe" banging. I was talking about its origin (which, by the way, is also the origin of time, so, it can't even be said to have occurred "before" as there's no time before time, therefore it's not located at all in time... good luck bro! 🤣 )

You're literally asking the origin of the first thing. Whether it's the universe or you assert something else, something would've had to simply exist for as long as anything has existed. 😀

firage wrote:

You're literally asking the origin of the first thing. Whether it's the universe or you assert something else, something would've had to simply exist for as long as anything has existed. 😀

Man you won't believe how inspiring your sentence is, NOT in the "direction" that appears immediately, but towards something else.
I don't wanna go off topic tho.

aries-mu, the onboard IDE controller on UM8881/8886 chipset boards, like the MB-8433UUD, will not work at 40 MHz. You will need to use a BIOS-controlled 2/3 PCI divisor to run the PCI bus at 27 MHz for the onboard IDE to work. I don't recall if the IDE controllers on SiS 496/497 boards work at 40 MHz.

The simple answer is that double-bank cache allows for less wait states, especially on marginally stable configurations, compared to single-banked cache. Double-bank cache allows for interleaving. Double-bank cache generally uses 9 SRAM chips, while single-banked cache uses 5 chips. The MB-8433UUD natively allows for up to 256K of double-banked cache, or 512K of single-banked cache. The MB-8433UUD can be modified with some effort to allow for up to 512K or 1024K of double-banked cache.

Normally,
9 pieces of 32Kx8 DIP-28 SRAM modules make 256K double-banked
4 pieces of 32Kx8 DIP-28 SRAM modules + 1 piece of 64kx8 makes 256 single-banked
8 pieces of 64Kx8 DIP-32 + 1 piece of 32Kx8 makes 512K double-banked
4 pieces of 128Kx8 DIP-32 + 1 piece of 32kx8 makes 512K single-banked
8 pieces of 128kx8 DIP-32 + 1 piece of 64Kx8 (or sometimes 128kx8) makes 1024K double-banked

Personally, I would search for FPM RAM as it is more versatile and doesn't degrade performance. For example, on eBay, you might search for "SIMM 72 32 MB FPM" 72 is for 72-pin SIMMs. 32 MB is the module size. Every time I search for RAM, I also check the datasheets for the individual IC's on the module, because sometimes you get 3.3V SIMMs being sold as 5 V. All consumer-ended 486 board's I've seen use 5 V.

When searching online for SRAM, it is best to hunt down some part numbers and search from there. E.g. 'IS61C1024' for 128kx8 modules, 'W24512AK' for 64kx8 modules, or 'W24257AK' for 32kx8 modules.

You generally cannot modify the PLL in the computer, however, there are very often undocumented jumper settings which yield 50, 60, and 66 Mhz outputs. Sometimes you need to solder on a missing jumper header, or sometimes the jumper headers are already in place and you just need to try different jumper combinations.

Promise Ultra 100 is an IDE controller which works on my 486's. The drawback, though, is that I cannot get a CD-ROM drive to work with it in DOS. This seems to be a known limitation. The CD-ROM will work in Windows though. For such situations, I tend to use the Promise for the HDD and the onboard IDE for the CD-ROM, but then you run into that 40 MHz FSB issue when using the onboard IDE. So if I am using the FSB at 40 MHz, I tend to use a SCSI controller card, which allows for bootable CD-ROM's, CD-ROM access in DOS, and HDD access. If you like, you can just use an ISA SCSI card, e.g. 1540/1542/1520/1522, just for the CD-ROM and us the Promise for the IDE HDD. SCSI HDD's are getting hard to find, especially the quiet ones. Although, there are SD to SCSI solutions, http://store.inertialcomputing.com/

Advertising items for sale is prohibited on this forum, so best not to ask.

Wait states rae adjusted in the BIOS. FSB frequencies are adjusted on the hardware, usually by jumpers. The PCI freq is normally the same as the FSB, unless you go into the BIOS and set the PCI freq. to be 1/2 or 2/3 of the FSB. 2/3 option is very rare and I've only seen it on UM8881/8886 based boards, namely the M919 and MB-8433UUD (it is automatic on the M919).

There is no pipeline burst for 486. you are limited to direct-mapped cache. Not possible to buy cache at the "computer store" in 2018. Online shopping is infinitely larger than the "computer store".

Not possible to run a 486 in a Pentium motherboard. The exception are high-end workstations or servers from around 1992-1995 which used riser cards for their CPUs. You could get 486 or Pentium riser cards. Such systems sometimes allowed for dual 486 risers.

I do not have any experience with VLB or PCI cards at 50 MHz.

Adaptec AHA-2842A is a nice VLB SCSI controller because it has a jumper which allows you to run the CPU's L1 cache in write-back mode, assuming the motherboard supports WB L1 cache.

If anyone knows of PCI Ultra 33/66/100 IDE controller which allows for DOS CD-ROM access and/or CD-ROM bootability, please let me know.