brostenen wrote:

soviet conscript wrote:

I have no idea why this is the case, there just sheets of metal with one big hole in them. I suppose the only reason there scarce is because there wasn't much demand. I don't see why someone cant make their own with a cheap piece of sheet metal, a small drill, a dab of hot glue (or tape) and 20 minutes of their time.

I have seen a couple of early ATX cases, that was sold with shields for both AT and ATX boards. The ATX plates was more or less identical the first years.
The cases I saw them bundeled with was A-Open cases. I think people just threw out what was left when a computer was being build.

I have one of those cases with the magic ATX ---> AT I/O sheild, I bought it 1997 😀

There were also an ATX power switch included but also mounting holes for an AT power switch, you used the same power button with both types.

as far as the ATX form factor goes it looks like the models that have a "-X" in the model name around the time period of 95/96/97 were the first to undergo the form factor switch from AT to ATX

for example if u look at the Asus TX97 -- its an AT form factor with the big AT keyboard port
but then the Asus TX97-X -- has ps/2 style keyboard port + the form factor has been adjusted to fit ATX cases

the TXP4-X also is ATX format..
but the Asus VX97 is AT format (no "-" before the 2nd X!)

if i was to focus on getting a full on ISA / AT 486 board (no PCI slots). should i make sure to have a socket for Math co-processor? And what about extended ISA?
is that important? what the difference between EISA + VESA?? im confused 😀

486DX have built in math coprocessor. No need to get an ISA only machine unless you want period correctness - PCI motherboards are easier to work with than ones with VLB or some other kind of local bus.

soviet conscript wrote:

chrisNova777 wrote:

It is possible, several early ATX cases has AT mounts, but there will be a big hole at the I/O ports, unless you can find an AT backplate for ATX (almost non-existant!).

I have no idea why this is the case, there just sheets of metal with one big hole in them. I suppose the only reason there scarce is because there wasn't much demand. I don't see why someone cant make their own with a cheap piece of sheet metal, a small drill, a dab of hot glue (or tape) and 20 minutes of their time.

This annoyed me too. A few months ago I searched eBay up and down and found nothing. I contacted sellers that used to sell them, they also had nothing 🙁

Or finding solid IO shields, you know before they put the holes in them, that alone would help. But I think we need to just accept it and use it without a shield.

if you don't want to find a cheap piece of sheet metal and a drill you could always use cardboard and scissors, maybe paint it silver or aluminum......

it could possibly look better then a big giant hole.

Isn't there a shielding component to the I/O... well, shield?

I thought there was something about the case protecting the innards from electromagnetic interference and the like and you needed to have a more or less complete enclosure for that effect to actually take place, but I could be pulling that out of thin air.

If your still after a 486 motherboard, I'd first go with what's available to you. Its still possible to get one for a good price if your prepared to wait and not hung up on an exact board.
Regarding slots anything other then ISA is a bonus rather then a deal breaker if you ask me.
ISA is ISA, don't worry about EISA or whatever. The ISA standard was well established by then and any isa card will work on a 486 board
VL-BUS or VESA Local bus was new to the 486 era to get round limitations of ISA (or indeed EISA) Mainly used for I/O cards and Video cards. Cards are hit and miss and expensive. I wouldn't worry about VESA if I was you unless you want to play around with the technology.
PCI was at the very end of 486 era. Again can be hit or miss, bit more useful the VESA with planty of PCI video cards on the market but a good ISA video card is fine on a 486 as well.

can anyone offer any expertise with ram capacities + compatibilities??

i just checked the ram requirements of the early versions of cubase..
they are set around 2MB of ram.. but v2.0 requires 8MB of ram

I happen to have 4 x 16MB SIMM modules sitting here on the table...
as long as the board specifies that it takes SIMM memory will it be compatible with these 16MB SIMMs?

im now trying to find a board that has no pci technology at all..
and will take a 486 DX2 66Mhz CPU or 486 DX4 100Mhz even

im hoping that such a board would also be able to accomodate 16mb-32mb of ram, possibly up to 64mb of ram?
whats the max ram capacity/format for boards that have no PCI? is it capped at 8, 16, 32, or 64 MB?
also im not sure about distinguishing between "EDO" or "non-EDO" ram?
i will have to google that info..

was there ever any pentium boards that had only ISA slots (NO PCI) ?????

to explain my intereste i remember reading inside the cubase readme.txt about an error that occurred that caused audio dropouts while recording
that was related to the Video Cards PCI driver taking control of the CPU via Bus Mastering PCI technology.. and that only certain manufacturers gave u the ability to disable or enable this type of direct CPU access in the driver settings dialog.. one of such companies was MATROX..
but i figure if there is no PCI slots on the board at all then theres zero chance of having to worry about this PCI related issue.... and the whole point of building a legacy system was to use the older technology .. so..
basically im asking if theres any boards that would be ISA only + stil let me use a pentium processor....

im guessing this is where The "pentium OVERDRIVE" comes into play?

Nope, there never was a Pentium ISA-only board.
Honestly, just get a PCI 486 board and, if you have audio dropouts, get an ISA vídeo card (just because you have PCI slots it doesn't mean you have to use them).
Also, some boards/BIOSes allow bus mastering to be disabled entirely. I know my Compaq Deskpro 2000 (Pentium MMX 200) has that.

I don't know of any Pentium class board without PCI. Just stick with your plan for a 486 ISA board. I think thats a great start and those boards are always fun. you'll probibly end up with 1 or 2 VLB slots as well but don't let them intimidate you. They work fine as ISA slots if you choose to not go the VLB route.

EDO RAM is a little faster but it gives some boards "issues". you'll be fine with FPM RAM. The cap for many 486 boards seem to be 32 or 64MB of RAM. honestly 64 is major overkill for the era. even 32 is kinda overkill. most early 90's dos machines will work very well with as little as 8mb of RAM.

if you want a Pentium in a ISA/VLB type board a 83mhz Pentium Overdrive should be compatible with most 486 boards. They aren't quite as fast as "true" Pentiums on a Pentium motherboard but they are still really fast and offer the best FPM performance.

Runicen wrote:

Isn't there a shielding component to the I/O... well, shield?

I thought there was something about the case protecting the innards from electromagnetic interference and the like and you needed to have a more or less complete enclosure for that effect to actually take place, but I could be pulling that out of thin air.

Electronics have to pass government standards for emissions. Setting that aside, your computer will run just fine and it's very unlikely you'll pick up any noise from it on your nearby Hi-Fi wires, or on your remaining antenna radios & TVs.

The technical background you're likely trying to remember is the Faraday cage
https://en.wikipedia.org/wiki/Faraday_cage

thanks for all the replies Guys!!!!

i also forgot to mention that i 100% absolutely need SERIAL + PARALLEL ports - i dont see any headers on some of the 486 only boards.. were serial + parallel ports on these machines added via some type of ISA I/O addon card?

i see ribbon headers/connectors on more recent boards..
Asus P5A-B (near keyboard AT port)
Asus P/I-P55T2P4 (to the left of the ram slots? near com1+2?)
Asus P/I-P55T2P4/S (near the AT keyboard port)
Asus PCI/I-P54SP4 (under the floppy connector? i think thats a parallel header? 26 pin?)
Asus P/I-P55TVP4 (near AT keyboard port)
Asus PCI/I-486SP3G (near at keyboard port)
Asus PVI-486SP3 (near AT keyboard port)
Asus SP97-V (near AT keyboard port)
Asus VX98 (near AT keyboard port)
Asus TX97 (near AT keyboard port)
Asus TX97-LE (near AT keyboard port)

but i dont see any headers or connections on the older pre-pci 486 boards
Asus ISA-486C
Asus ISA-486SV2
Asus VL/I-486SV2QX
Asus VL/I-486SVG0
Asus PVI-486AP4 (only has an IDE header?)

did these boards need some type of I/O addon card?
if this were true this would account for the reason why the manuals all say "multi i/o" or "super multi i/o" as if it was something to brag about at the time !!!

another question i have is.. is it best for old 486 systems to use SCSI for boot drive?

i had thought i was going to use a Compact Flash via CF/IDE adapter, but i was just readin about the PCI-SC200 being used in an asus board for SCSI disk access.. then i remembered.. SCSI Was alot faster then IDE back in those days...
is there any real benefit to use a SCSI card in combination with a SCSI-CF Adapter? does this make sense?

some 486 boards have built in I/O controllers, many do not. if the board does not ISA multi I/O controllers are plentiful and cheap. SCSI is faster and supposedly more reliable but sometimes its a bit more of a pain to set up. they are also a bit more expensive and hard to find and usually (but not always) loud. I recommend keeping it simple and go IDE since your not trying to built some ultimate speed demon setup.

so theres no compatibility issues -- i can literally grab any "ISA I/O controller" and it will work + be compatible?
i guess the upside of this is i might be able to find a parallel port (IEEE 1284 i think they call it ..) that supports ECP or EPP modes?

http://www.startech.com/ca/~ISA1P

what kind of graphics card would i need for a board like this? (not this EXACT Board but a similar board.. )
ie: if u could give me a hint on what to search for .. do i search for VLB? or VESA? + "Graphics" ?
how do i know if a board support "intel overdrive" cpu?
i cant even look up which cpus are supported by most of these boards!!
sorry for all the questions but im really trying hard to make sure i do this right the first time. + order the right things that i need...

i did some searches + saw that people want 200$ for ISA ATI video cards... thanks to idiots over pricing 486 stuff on ebay.

Any isa i/o controller should work or vlb controller if you get a board with vlb slots. Overdrive compatibility depends on the board, you would need to research. Most should work fine in my experence. Look for graphics cards based on the tseng labs et4000 chip. Cirrus Logic put out some decent video chips as well. Vlb versions will be faster in general. Isa cards based on the trident 8900D chip are suprising fast for being a trident card.

If you can find, get a VLB card with IDE/Floppy controller instead of an ISA one. VLB is faster.