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Need part number for Everex 32 nit memory card.

Chuck(G)

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I suspect that your chances of finding the add-on memory board for this Everex board are slightly worse that of you winning Powerball twice in a row.
The issue is that there is plenty of room for memory on the motherboard, so few, very few, opted to pay extra for the board. And these things are sui generis, usually specific to one model board.
I've got an older 386 somewhere with no memory on the AT-sized motherboard (chipset? what's that). The only memory is on the plug-in memory board, all 13MB of it. Without that memory board, the system won't boot and turns into a wall decoration.
 

Chuck(G)

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picture? there were at least three different connector possibilites for ram cards
the most common was the Intel one
Without digging into a pile and opening a case, I believe it's this one. Memory card is a double-decker, using DIP RAM packages. Micronics didn't even keep the same memory card layout for their 386 systems.
 

mR_Slug

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I'd echo Chucks post. This thing can take 8MB on the board without the expansion card. VERY few would have bought one.

FWIW 4MB was common in the high end of late 1990. This looks like a late '80s board. More than 8MB is the tale end of the 486 era.

See here for 1990 & others:
 

bobconan

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Here is the diagram.
 

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GiGaBiTe

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Here is the diagram.

That's not a diagram, it's just a reference telling you where the slots and sockets are for memory.

The real card is going to have a whole lot more support logic on it. You can't just wire up memory chips directly to the ISA and system bus and expect them to work. What's really going to complicate things are the cache chips, because CPU cache needs a bunch of logic to determine what to hold in the cache, when to retrieve data from the cache, when to flush the cache and a lookup table in TAG memory.

It wouldn't be impossible to lay out a memory card and have it fabricated, but it would involve quite a bit of reverse engineering to know the pinout of the special connector and how the system uses it. You could likely use another similar memory card from the time to get clues on how to build yours, but again, it'd require a lot of extensive and deep electronics knowledge.
 

twolazy

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I have to agree, 8mb is more then enough on a 386. Anything more isnt really going to do anything useful, unless you intend on using it for CAD or graphics programs like Ventura. It would be like having 256gb of ram nowdays, on a regular pc. Sure you can do it, but theres no real benefit past say 32gb...
 

Al Kossow

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You can't just wire up memory chips directly to the ISA and system bus and expect them to work.

The isa connector is probably only there for power.
The logic on the motherboard handles the cache/dram arbitration. What's on the memory card is
address decoding / multiplexing and timing for the drams. It would probably be possible to use
modern big srams and reduce the component complexity even more
Here is what an Intel 2meg card looks like
 

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bobconan

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That's not a diagram, it's just a reference telling you where the slots and sockets are for memory.

The real card is going to have a whole lot more support logic on it. You can't just wire up memory chips directly to the ISA and system bus and expect them to work. What's really going to complicate things are the cache chips, because CPU cache needs a bunch of logic to determine what to hold in the cache, when to retrieve data from the cache, when to flush the cache and a lookup table in TAG memory.

It wouldn't be impossible to lay out a memory card and have it fabricated, but it would involve quite a bit of reverse engineering to know the pinout of the special connector and how the system uses it. You could likely use another similar memory card from the time to get clues on how to build yours, but again, it'd require a lot of extensive and deep electronics knowledge.
Yes , I was just providing it for Al Kassow. I have experience with adding memory for 68HC11's, but that feels simple compared to this.
 
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bobconan

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I have to agree, 8mb is more then enough on a 386. Anything more isnt really going to do anything useful, unless you intend on using it for CAD or graphics programs like Ventura. It would be like having 256gb of ram nowdays, on a regular pc. Sure you can do it, but theres no real benefit past say 32gb...
CAD is actually what I want to do. I added the co-processor. Also thought it might be interesting to try running win 95 on it.
 

bobconan

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The isa connector is probably only there for power.
This was my guess as well. The 32 bit bus is probably the proprietary connector, on the motherboard it appears to be a 16bit ISA connector in reverse. My real hope is that i could use a different 32 bit card and rig it up. I guess I should start with the datasheet for the 80386dx?
 
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twolazy

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What are you going to use for cad? AutoCad R12? R10? 10 works great on 8mb, 12 takes advantage of more ram, but you ideally want a 486 or better. Dont bother with 13, its super buggy...
 

bobconan

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What are you going to use for cad? AutoCad R12? R10? 10 works great on 8mb, 12 takes advantage of more ram, but you ideally want a 486 or better. Dont bother with 13, its super buggy...
Was hoping for r11 because of the win 3.1 extentions. I do know I want a digitizer but am having trouble sourcing one with drivers.
 
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bobconan

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After spending an hour on Usenet(Google groups) I have discovered the part number for the Everex step 386 memory Expansion to be EV-1817. Maybe this will be helpful to someone else. I doubt I will actually ever find one.
 
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