pictures would help quite a bit. You mention three open memory slots on the video card? Thats a highly un-usual number from my experience.

You say you want put a board with PCI slots in your riser slot? I don't think you are going to be able to do that, unless the expansion slot is already a PCI slot.

If it is ISA or EISA (probably just ISA) then you're limited to ISA cards. Depending on what vintage it is,
it might have EISA or even a VLB riser slot, but without seeing pictures it is hard to say. If the slot is black
and is 16bit then it is a 16 bit ISA slot. If it is black and shorter it is an 8 bit ISA slot. If the slot is the same
length as the 16 bit ISA slot but is brown, then it is an EISA slot. If it looks like a 16 bit ISA slot but has a smaller, brown card slot at the end then it is VLB.

My guess is you have either a 16 bit ISA slot or maybe even an EISA slot. Pictures would help us figure out what you have. If this system was originally meant as a server system it might be an EISA slot.

Hi snorg,

I'll upload pics tomorrow - I was so impatient to ask my questions, that I didn't took the shots.

The slot is EISA. I forgot to mention it.

Rgrds

Hm, I got somewhat disappointed when I had a second look at the case "contents".

Haven't tested the CPU yet (need to arrange jumpers first)

Then we have this overview (there's a piece of metal in the empty part of the box, that holds one HDD and a FDD

And, please ... tell me what the hell is this? It's not EISA.

That slots on the board it self is not EISA..

These brown slots are EISA:

That slots on de boards it self are thinking proprietary ones from that manufacturer..

The brown slot on the riser board is a Vesa Local bus slot.. Its the predecessor for PCI slots..

I see that your system has already:

- A graphics card onboard
- IDE controller onboard
- Floppy controller onboard.

The cirrus chip on the motherboard is the graphics chip for the videocard. Those brown sockets are memory sockets to upgrade the onboard graphics card to more memory so higher resolution would be possible.

I can recommend to buy a pressed air cannister en get rid of all that dust on that motherboard..

1. Purple - PS/2 ( i think) keyboard and mouse connector
2. Pink - VGA port, parallel and serial port;
3. Yellow brushed - onboard graphics card (could be on the VESA local bus connected)(have SOJ memory slots to upgrade video memory..
4. Green - 72 simm system memory slots.
5. White - processor with fan
6. Brown - system cache memory
7. Red - System bios ROM
8. Black - biggest is an IDE controller to connect a harddisk on (maybe a cd-rom if you have luck) the smallest is for the floppy drives.
9. Orange - system battery.

Now that's service Robin4!

I like such OEM boards. They are well built and usually well documented. Also quite stable and almost always with PS/2 connectors. On my Acer I filled the empty video memory sockets and performance increased. Also has a coin battery like my acer.

It's definitely a nice system. I would be surprised if the system doesn't work.

Iam not really in those systems.. They have limited options for upgrading.. Weird thing is that on the other side of the riser board there is also one 16 bit isa slot on the picture.. But the case doesnt have any room on that side to stick a normal isa card in.. And maybe the graphics card isnt great either on performances.. Then you could disable the onboard one.. (there are still are jumpers to disable it near the graphics card self)

But then you wasting one isa /VLB slot on this system.. Then remains one slot left for only a soundcard..

So i really dont like those systems.. But when you have laying around, and doesnt have other systems to cope with. Then its a option to deal with.

Oh, Robin4 ... thanks for that answers and I really appreciate all the work you did.

This particular PC is part of my past - the videocard is OK for me - I can disable it, but I don't plan to (you can see the graphics chip in my first post - cl-gd5428080qc-a). The memory chip is NEC 424260-70 9508MU027, but I cant get the idea of the memory size. I remember playing Transport Tycoon Deluxe and Mortal Combat on this board. Anyway, I think it will be OK.

Took a picture of the manual:

And this is where I need your help. You can see my CPU in the post above - it's a DX4-120. This manual says to leave the:
- JK1: 5-6 ON
- JC1: 4-11 ON

But I see no settings for a CPU FSB - I hope the DX4 won't run at 20x3 = 60Mhz's only?

And if I put Am 5X86, what jumper settings should I use? I remember only that the multy should be at 2.0x (the FSB at 33, of course, but as I said - I see no FSB here).

Some more questions as follows:
1) What is ECP settings?
2) If I can put max 256K cache memory, what is the optiomal amount of RAM I should use - 64 MB?
3) I have 9 slots for cache, but I can use a max of 256K, so I need 8 pieces of 32K and the last slot will stay empty?
4) I have the onboard IDE controller - promise pdc20230c. Can I use two devices with it? I mean, it will be great if I can put a regular HDD and a CF CARD (no space for 2 disks). Anyway, do you know the max size HDD I could put, or it depends only on BIOS, not the chip itself? I have a 3.2GB Quantum, that should be in good shape - I can make two partitions of 1.6, that should be fine, probably?

And I actually have a low profile network card, that fit's in the ISA slot on the back - it's an AMD network adapter that I have never heard of 😀

Space Cowboy wrote:

Some more questions as follows: 1) What is ECP settings? 2) If I can put max 256K cache memory, what is the optiomal amount of […]
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Some more questions as follows:
1) What is ECP settings?
2) If I can put max 256K cache memory, what is the optiomal amount of RAM I should use - 64 MB?
3) I have 9 slots for cache, but I can use a max of 256K, so I need 8 pieces of 32K and the last slot will stay empty? Why the hell did they put it - I mean ... they could make only 8 slots?

You will need 9 pieces of 32k. The 9th or 1st is the TAG ram.

However I always wondered about this. In my 486 all 9 chips are the same 15ns. However I have heard that the TAG should be faster. This always interested me...

ECP has to do with the printer port. Not sure exactly, but it might be faster for parallel drives like Zip 100.

Regarding FSB, the board should for sure have jumpers.

With my Acer, I took the machine apart and made High resolution images. Donutking managed to spot the FSB jumpers which I simply was unable to spot 😁

Looks like your missing the metal panel part from that network card.
If your going to use it (i certainly would use it) I highly recommend mTCP http://www.brutman.com/mTCP/ for your network needs

Actually, awergh, I have this piece, I just haven't photoed it 😀 Thanks for the link, it will be of use.

The board in your machine actually seems pretty decent, save for the lack of ISA slots. I used to have a 486 with a Cirrus Logic VLB video card and it was pretty decent, so what I would do is add more ram to the onboard video card, throw in a sound card, and you'd pretty much be set. It doesn't have as many ISA slots as an average 486, because it doesn't need as many. 😁

These are the cache slots

Hm, they start from M6 to M14 (the first M's are for the video memory), but as you can see, on 8 of them, there's an inscription SRAM 32K), and the 9th one down there has no inscription in it

I'm quite confused.

People, I have a major problem - I took that Am 5x86 133Mhz for tests, and now I see I don't have a jumper to set my voltages.

Looking at this manual, do you beleive the board is able to deliver 3.3V?

According to this article in Wiki, the DX4 is supposed to run at 3.3V, and it's listed in my Mb's manual. The Am 5x86 requires 3.45V, but I beleive it will run at 3.3V

http://en.wikipedia.org/wiki/Intel_80486

Space Cowboy wrote:

These are the cache slots […]
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These are the cache slots

Hm, they start from M6 to M14 (the first M's are for the video memory), but as you can see, on 8 of them, there's an inscription SRAM 32K), and the 9th one down there has no inscription in it

I'm quite confused.

The eight marked with 32k are the sockets for the cache DIP chips.
The non marketed is for the TAG ram chip (this need also be a 32k ram chip) (left bank, the lowest socket)

When installed those DIP chips, you need to take care with the oriontation.. Theres is little notch on the left side on those sockets..
The dip chips do have a little point on the top of the chip.. So that point needs to aligned with the notch on the socket.. (same story on those SOJ graphic card memory chips)

I also saw that the IDE controller is connected internally on the VESA local bus, so no seperate I/O card is needed..
On one floppy drive interface you can install two floppy drives..
On one IDE connector (the board only has one) you can connect two disk drives when needed.. Don`t know if the board is capable to detect flash cards.. Some dont work.. Only works on harddisks.

I dont think this motherboard can use the 40mhz bus speed.. On your manual i dont see any options for it.
The processor you are using now is a AMD DX4 120MHZ Write-back one.. I guess thats a P24D processor.. The P24T setting is for overdrive processors.

I only dont know whats that `CPU clock down mode` is for.(maybe like a sleep mode or so for energy savings) I think then you need to set it as 20mhz bus speed (because of DX4 behind it) Perhaps the 120Mhz version wouldnt be supported on that board..
Its limited till 100 mhz i guess on the normal DX4 processors..

Then you have to set is as: DX4 multi JC1: X3 , CPU clock normal mode 33mhz JK1, Then you need to know if you have a Write -through processor or write back.. When you want to set this 120mhz processor to 100mhz then: Select cpu P24D JC1 and JC2 to internal cache write back... When you have a 100 VT processor then you have a write through one and have to set the settings to write through.

When you want to use a AMD 5x86 then you need to set it as a DX2 66 processor.. Then you also need to set the DX4 multi Jc1 to muliplier 2x.. But i really dont know if this system can cope with DX4 120mhz and AMD 5x86 processors. I guess 100mhz would be the fastest processor for your motherboard.

I think that your onboard graphics card uses 512KB now. I Guess this is upgradable to 2MB of graphics memory, (most VLB are capable to upgrade those to 2MB graphics memory) This memory doesnt provide you more speed from your graphics card.. You only can use higher resolutions..!

To set a 120MHZ processor you need to have a 40mhz system clock with 3 muliplier..

But how about the Voltages? I see no option for changing them, and the regular 486 works at 5V.

My DX4-120 works are 3V and the Am 5x86-133 works at 3.45V.

I doubt the MB will detect what CPU is in it and correct the voltage by itself 😀

This is what really kills me 😀 I have them both in front of me, and I'm not ready to risk to start them before I know (how) I can run lower voltage.

Boards can auto-detect the voltage. I found a guide ages ago which involves sticking a wire between two pins, turning the PC on and measuring the VCore.

Best best however is the Intel 486DX4 overdrive. It comes on a little PCB with a voltage regulator. The 5x86 isn't that much faster and if you want speed then just get a Pentium.

For the voltage you need to look on your motherboard and see if its having two Voltage regulators.. Then it is a auto voltage board.. If there is one it also can support 3.3volt.. If it has nothing then it is a 5 volt motherboard.. Then you need a voltage regulator composer board.. But the question still is, does it support the DX 4 100 mhz version or higher.. So if there isnt any bios upgrade then you still have limited options on this thing.

Look on the right near the cpu socket:

It has two Voltage regulator, so thats an auto voltage motherboard.. It will do both 5 and 3.3 volt.. And yes an AMD 5x86 will run on 3.3 volts.. Some motherboards doesnt have 4 volts or 3.45 volts..
And 3v on a 486 DX4 is actually 3.3 volts.

With AMD 5x85 you need to set the system bus speed to 33 mhz.. then set it to 486 DX 2 setting.. (i think this will do 2x 33 mhz = 66mhz) Then you need to set the DX4 multiplier on x2 is well.. Then it gives your 132 Mhz..
If the board regonize the cpu then you would see AMD 5x86 133 - P75... It the board doesnt regonize you will see: AMD DX2 @ 132Mhz.

Watch out that you place the processor in the same direction as the old does, and need to use the same pin holes.

Alternatively, on some boards the am5x86 at 4X won't boot at all if it is rejected by the BIOS. In this situation you can only run in 3X mode at 100 or 120MHz.