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Building a new (old) computer.

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First post, by Linkintime

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The motherboard is a 486ip2v of unknown brand. I checked a few databases but haven't found it yet. There seems to be Cache slots but I'm not sure what would be compatible. I ended getting a 5x86 instead of a 486 dx2 66 but both would be great. Any suggestions on Cache? I'm hoping to put as much in as possible.

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Reply 1 of 21, by BitWrangler

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Looks like one of these or related models...
https://www.ultimateretro.net/en/motherboards/10125
Or one of bottom half of these
https://www.ultimateretro.net/en/motherboards … ufacturerId=548
Nothing looks exact, some of the Gateway ones are closer, maybe for another OEM.

Unicorn herding operations are proceeding, but all the totes of hens teeth and barrels of rocking horse poop give them plenty of hiding spots.

Reply 3 of 21, by Disruptor

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Warning!
As I have a Saturn II based motherboard too, I can say that DRAM modules have to be installed pair-wise. At least my board won't boot with a single DRAM module.

Reply 4 of 21, by Deksor

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Hello, could you please take a nice picture of your board and dump the bios for proper documentation on ultimateretro ? 😁

Trying to identify old hardware ? Visit The retro web - Project's thread The Retro Web project - a stason.org/TH99 alternative

Reply 5 of 21, by luckybob

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I'm hoping to put as much in as possible.

That's what she said!
*laughs like a school child for 5 minutes, and stops when I see nobody else laughing*

But seriously. That board screams "ACER OEM". And the first board Bitwrangler posted looks right. Too many things line up.

It looks like you need 5x 256kbit sram chips. They are common enough on the ebay. Without going into reasons why, don't buy anything that comes out of China. NEW chips can still be bought: https://www.mouser.com/ProductDetail/Renesas- … MD%2FZNgZjhk%3D (i'm like 95% sure thats the right chip, dont take that link as gospel.)

It is a mistake to think you can solve any major problems just with potatoes.

Reply 7 of 21, by Linkintime

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"As I have a Saturn II based motherboard too, I can say that DRAM modules have to be installed pair-wise. At least my board won't boot with a single DRAM module."
Luckily I got a pair.
"Hello, could you please take a nice picture of your board and dump the bios for proper documentation on ultimateretro ? "
I plan to. I'm hoping there is a program to do it from a floppy.
"It looks like you need 5x 256kbit sram chips. They are common enough on the ebay. Without going into reasons why, don't buy anything that comes out of China. NEW chips can still be bought: https://www.mouser.com/ProductDetail/Renesas- … MD%2FZNgZjhk%3D (i'm like 95% sure thats the right chip, dont take that link as gospel.)"
Thanks looks great.
"I have had problems in my Saturn II based motherboard to run a write back processor.
Please try first with a write through 486."
Noooo! Bummer. I may be going back to a dx2-66 after all. If I do happen to get the 5x86 working I'll let you know.

Reply 8 of 21, by Disruptor

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Linkintime wrote on 2022-01-14, 18:06:

Noooo! Bummer. I may be going back to a dx2-66 after all. If I do happen to get the 5x86 working I'll let you know.

It is alive?
Great!
It has an outstanding memory performance.

Reply 9 of 21, by Disruptor

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HDDs? Since the onboard IDE connector is not soldered, I recommend to use a PCI IDE addon card or a PCI SCSI controller.

Warning. Your empty single SRAM socket may need another SRAM type than is needed for the 4 empty sockets.
Perhaps it is a dirty tag ram socket, perhaps it needs the same SRAM type than the soldered module. I cannot read the type on your photograph.

Reply 10 of 21, by Disruptor

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You can do me a favour please.
Please first try to run your board without additional cache modules at all.
Then install the 4 cache modules. Take care about the direction of the modules.

I'm not sure whether the 5th SRAM socket is a dirty tag ram socket or a socket to extend the cacheable area.
So Please leave it empty until you have read this topic and sent benchmark results to the current topic here.
486 L2: Comparison between Write-Through & Write-Back (with and without dirty tag ram)

Reply 11 of 21, by Linkintime

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I just got it today. I am just testing it out of the case and it boots and recognized all the ram but it says System Battery is dead replace and run setup then real time clock error (which is not surprising with the old Dallas real time clock). I've seen a mod where you dig away on the side to reveal terminals and attach a cr2032 battery. It then says press F2 to run setup. That's not the odd thing. The keyboard wont respond. No lights no anything. If I boot without a keyboard it gives a keyboard error. If one is plugged in no keyboard error but the keyboard won't respond. The motherboard does seem to have a spot for key lock.

Reply 12 of 21, by Linkintime

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"HDDs? Since the onboard IDE connector is not soldered, I recommend to use a PCI IDE addon card or a PCI SCSI controller.

Warning. Your empty single SRAM socket may need another SRAM type than is needed for the 4 empty sockets.
Perhaps it is a dirty tag ram socket, perhaps it needs the same SRAM type than the soldered module. I cannot read the type on your photograph."

I did get an eide controller card. Gotcha on the Sram sockets. I'll hold off on installing them.

You can do me a favour please.
Please first try to run your board without additional cache modules at all.
Then install the 4 cache modules. Take care about the direction of the modules.

"I'm not sure whether the 5th SRAM socket is a dirty tag ram socket or a socket to extend the cacheable area.
So Please leave it empty until you have read this topic and sent benchmark results to the current topic here.
486 L2: Comparison between Write-Through & Write-Back (with and without dirty tag ram)"

Sure if I get past this boot problem. I'll be happy to try it.

Reply 13 of 21, by Linkintime

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There is a key lock. I did notice it had P24D which is for dx2 writeback.

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Reply 14 of 21, by Linkintime

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Here are some images of the SRAM.

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Reply 16 of 21, by pancakepuppy

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NJRoadfan wrote on 2022-01-20, 02:34:

The date sticker screams Gateway 2000. Its likely the Animga board linked above.

I agree with this, my Gateway P5-90 has the same sort of stickers on the motherboard and add-in cards (but with a slightly higher number and 5 months later date)

Based on the cache chips on your board and the Intel chipset datasheet, you should be able to put 71256SA12TPG (12ns 32Kx8) in all the sockets and have the maximum cache configuration for the board. 12ns is faster than is required for the data cache chips but the tag needs to be at least 15ns (I think). It looks like your board has a 12ns part installed for the first part of tag, and if you buy new parts they all seem to cost the same anyways so might as well get the faster parts for all of them right?

Reply 17 of 21, by Disruptor

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Linkintime wrote on 2022-01-20, 02:33:

Here are some images of the SRAM.

I can't clearly read the picture of the first SRAM, but it seems to be a 71256 (32Kx8) - that is the tag ram.
On the 2nd picture I identify a CY7C187 in the left of the 4 soldered SRAMs, that is a 64Kx1 - that is the dirty tag ram.

So it is clear that the 5th socket is for a 32Kx8 SRAM and it is used as extra tag ram to enhance your cacheable area.
It should be the same module that is used in the other 4 sockets.

Without populating it, the limits are in write back mode 128K L2 -> 32 MB, 256K L2 -> 64 MB. (because of the extra 64Kx1 dirty tag ram it has the same limits as in write through mode)
When you populate it, it uses 2 (out of 8) extr a tag bits and you can try 128 MB RAM (or 256 if possible wth this chipset, but who needs that).

Reply 18 of 21, by Linkintime

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"Without populating it, the limits are in write back mode 128K L2 -> 32 MB, 256K L2 -> 64 MB. (because of the extra 64Kx1 dirty tag ram it has the same limits as in write through mode)
When you populate it, it uses 2 (out of 😎 extr a tag bits and you can try 128 MB RAM (or 256 if possible wth this chipset, but who needs that)."

Looks like I'll have to wait a bit. I can't get a keyboard working. I've tried three PS2 native keyboards. It just has press F2 After the real time clock error. The seller is letting me swap the motherboard. Thanks for the help guys.

Reply 19 of 21, by m0e

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I realize I am late to the party but I am curious if the OP managed to get this board running. I have a Gateway 2000 P4D-33 Baby AT that appears to have this same board installed. I am not sure this is the place to post this but this thread is the only thing I have googled that shows this actual board, If it needs to be moved elsewhere I hope a mod can put it where it belongs. The production date stickers on both the board and the case show June 1994. I was given this computer over a decade ago with the original HDD removed and have held onto it because of the working 5¼” floppy drive and the Iomega tape drive. A couple of years ago someone brought me an identical machine for data recovery, with the original software disks (3 ½” boot disk and CD with OS and drivers) so I made copies of the software. I recently found an 865MB hard drive that still works and would like to get it up and running. My issue is the BIOS doesn’t recognize anything connected to IDE. The IDE port on the board does not have pins but there is a Data Tech single IDE PCI card installed. The BIOS shows IDE 0 master/slave and IDE 1 master/slave but will not auto populate the info for either the hard drive or CD drive. I can manually input the info for the hard drive in the BIOS but I do not see any option to do that for CD drive. Even with the hard drive manually set up in BIOS booting to DOS from the floppy there are no IDE devices found. Any help would be appreciated and if anyone has a manual for either the board or computer or even the IDE card that would be helpful. Thanks in advance.