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itsvince725

Vince's Conquests

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Yeah. You'd think IBM might have had at least enough foresight to support 4MB but, no.

Another oddity of the first-gen 386 PS/2s (70, 80) is the DMA controller on the motherboard only supports a 24 bit address space. Therefore going above 16MB of RAM even with an expansion card requires some trickery. TL;DR basically boils down to if you're looking to go over 14MB of RAM look for a third-party card that has the BIOS extensions and memory controller to work "plug and play". (It's possible to break the 16MB barrier with options IBM sold but there's some mickey-mouse limitations and config nastiness.)

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I've only found one MCA memory expansion card so far (made by some company called Boca) and I don't know what it does or doesn't support.

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they are common:  https://www.ebay.com/itm/IBM-88F0075-ENHANCED-80386-0-14MB-MEMORY-ADAPTER-MCA-MICRO-CHANNEL-49F5507/141745795876?epid=1866219819&hash=item2100b53324:g:whcAAOSwHnFVzhmd

 

Others exist, if you wait on ebay cheaper ones will come up.  ctesales and nyce-distribution are avenues of last resort.  Their prices are an order of magnitude too high.  C'est la vie.

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Yep, definitely looks like the Bocaram/2 Plus to me. So with 8 1MB SIMMs that would give me 14MB, which should be serviceable enough for old versions of OS/2.

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It looks to me like that Boca card is only 16 bit? Googling for compatibility it looks like it will work in a Model 70, but I can only assume it'll be slower than a 32 bit card. Maybe it's not going to matter that much.

20 years ago I had a small pile of RAM cards for PS/2s that I ended up with... somehow, I don't even remember. Had a couple Orchard 16/32 cards that I think took up to 32MB. Sort of wish I'd held onto them now...

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I'm not a fan of that card to be honest.  Double so at that price.

 

Onboard is fine.  I've never had any real issues.  That said, the XGA2 card is what I would use if onboard was insufficient.  

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4 minutes ago, luckybob said:

I'm not a fan of that card to be honest.  Double so at that price.

I was being mostly tongue-in-cheek, of course. The ATI 8514 Ultra cards are significantly better than IBM's original 8514/A adapters but they're still by no means great. It's just the flippy-form-factor that makes them awesome. (There may have been a few other dual AT/Microchannel cards made but I can't name any off the top of my head.)

The Microchannel version of the ATI Mach 32 Ultra would be one heck of a find. I'm sure eBay would want ONE MILLION DOLLARS for that.

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yes, I would REALLY want one of those for my model 95.  I have little hope in finding one, but stranger things have happened.  I mean I did just find the dual Tualatin board I've spent 10+ years looking for.  

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When it comes to uncommon stuff, I'd be happy just to find a dual-PPro workstation without having to spend ~500 dollars building one.

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Intel PR440FX (BX is a P2 board) is what most people want in a dual PPro board. I had one running for a decade around 2000-2010 as a server (still works but I went with a different machine).

 

I also have a not so common Micronics W6-LI dual PPro board.

 

Scrapper love the PPro chips so even if you found the board cheap you will pay some cash for matching CPU's and then you have to deal with finding the heatsinks for them. Finding a complete working machine cheap these days is something to brag about.

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Back in the Netware days-- I used to run Netware 4 on a PC Server 365  with Dual PPros.  If I remember correctly,  it had a daughter card with the CPU's  and VR modules.  Cool machine. I used to get a kick out the two snakes on the Monitor screen. They got longer as the load on the machine increased.

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IBM made a desktop dual PPro machine. I worked on one for a guy who worked at the local university. A year or two later he was done with school and asked if I wanted to buy the machine for $40 (since I had a dual Ppro I passed). His machine has the 1MB cache 200Mhz CPUs (they were black not the gold metal topped ones you normally see).

 

IBM PC365 I think it was (same as the PC Server 365?).

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